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Q20-40 Answers are here...sorry guys - drtaher - ArchivalUser - 05-12-2009 Molecular studies on an abdominal lymph node containing lymphoma demonstrate t(2;8)(p12;q24) translocation. This is most compatible with which of the following diseases? A. Burkitt's lymphoma B. Mantle cell lymphoma C. Multiple myeloma D. Small cell lymphoma E. Small cleaved cell lymphoma Explanation: The correct answer is A. Burkitt's lymphoma is actually associated with three translocations. The common variant t(8;14)(q24;q32), involving the oncogene myc on chromosome 8, and the heavy immunoglobulin chain on chromosome 14. The other two variants are: t(8;22)(q24;q11), involving myc and the lambda light chain immunoglobulin site, and t(2;8)(p12;q24), involving the kappa light chain and myc. Mantle cell lymphoma (choice B), multiple myeloma (choice C), and small (not cleaved) cell lymphoma (choice D) are associated with the t(11;14)(q13;q32) translocation involving bcl -1 and the heavy chain site. Small cleaved cell lymphoma (choice E) is associated with t(14;18)(q 32;q21), involving the 14 immunoglobulin chain site and bcl-2. A newborn infant is noted to have numerous, light brown macules dispersed across her skin. The significance of this feature is due to its strong association with the development of which of the following tumors? A. Basal cell carcinoma B. Neuroblastoma C. Neurofibroma D. Retinoblastoma E. Wilms' tumor Explanation: The correct answer is C. Congenital "cafe au lait" spots are present in more than 90% of patients with neurofibromatosis. This autosomal dominant disorder is characterized by multiple neural tumors, especially neurofibromas, pigmented hamartomas of the iris (Lisch nodules), and cafe au lait spots, which usually occur over nerve trunks. Although the majority of neurofibromas in this disease are benign, the tumors can be quite disfiguring and psychologically damaging. Basal cell carcinoma (BCC; choice A) is a common, slow-growing tumor of sun-exposed skin. It develops in adulthood after years of chronic sun damage. Although malignant melanoma may arise from large congenital nevi, BCC does not. Neuroblastoma (choice B) is a common childhood tumor that arises anywhere along the sympathetic chain, and most commonly in the adrenal medulla. The tumor usually presents as an abdominal mass and is not associated with skin findings. The ocular neoplasm associated with neurofibromatosis is the Lisch nodule, not the retinoblastoma (choice D). Retinoblastoma is a neuroepithelial tumor usually identified by funduscopic examination of a child with visual changes. Wilms' tumor (choice E) is a neoplasm of primitive renal blastema that may be associated with congenital malformations of visceral organs, notably the adrenals and gonads, but not skin. It also presents as an abdominal mass, and is highly survivable with modern treatment modalities. A neonate develops bile-stained vomiting and progressive abdominal distention, and does not pass meconium over the first two days of life. The anus is patent, and the bowel loops are palpable. Plain radiograph shows bubbly meconium in the right lower quadrant. No localized areas of constriction or other abnormalities are noted. Which of the following is most likely etiologically related to this infant's condition? A. Cystic fibrosis B. Hirschsprung's disease C. Meckel's diverticulum D. Omphalocele E. Polycystic kidney disease 15 Explanation: The correct answer is A. The baby has meconium ileus, which is a manifestation of cystic fibrosis due to the abnormally viscid pancreatic secretions which "get stuck" in the small bowel. Meconium ileus can cause gut perforation with peritonitis and intraperitoneal calcifications (that may be visible on plain film). Meconium ileus complicated by intestinal perforation or formation of fistulas to the bladder or vagina must be treated surgically. Medical treatments for uncomplicated meconium ileus are now available, which use enemas, mucolytic agents, or pancreatic enzymes. Hirschsprung's disease (choice B) is a cause of congenital constipation related to absence of ganglion cells in a segment of bowel. The aganglionic bowel segment is narrowed because the lack of peristalsis keeps stool from moving into the segment. The distal rectum is always involved, and the lesion may extend proximally as far as the small intestine. The bowel proximal to the lesion is usually dilated. A Meckel's diverticulum (choice C) can form due to the persistence of the vitelline duct, which connects the developing gut to the yolk sac. They are classically located in the distal ileum within 30 cm of the ileocecal valve, and may contain ectopic pancreatic tissue or gastric mucosa. Omphalocele (choice D) is characterized by herniation of abdominal viscera through the abdominal wall near the umbilicus. In polycystic kidney disease (choice E), cysts of the liver and pancreas may occur; meconium ileus is not associated with this disorder. A 69-year-old woman is brought to the emergency room after falling off a step stool and fracturing her hip. Her past medical history is significant for several bouts of pneumonia during the past year. Laboratory results indicate a normal white blood cell count, but platelets are decreased, and the erythrocyte sedimentation rate (ESR) is elevated. X-rays reveal multiple lytic bone lesions. Serum electrophoresis demonstrates an M-protein spike. Which of the following is the most likely diagnosis? A. Chronic lymphocytic leukemia B. Monoclonal gammopathy of uncertain significance C. Multiple myeloma (plasma cell myeloma) D. Plasmacytoma E. Waldenström's macroglobulinemia Explanation: The correct answer is C. The patient is suffering from multiple myeloma, a neoplastic proliferation of plasma cells (or their precursors) found within the bone marrow. These malignant cells are responsible for the production of excessive amounts of immunoglobulin (usually IgG or IgA), producing an M- protein spike, and increasing the ESR. The decreased platelet count probably reflects infiltration of the bone marrow by myeloma cells. It is not unusual for patients with malignant myeloma to have recurring bacterial infections, particularly pneumococcal pneumonia, because the overall production of normal immunoglobulins of all isotypes is decreased. Lytic bone lesions due to infiltration by myeloma cells may lead to pathological fractures. All of the other disorders listed can be associated with an M16 protein spike, but this is a nonspecific finding. Chronic lymphocytic leukemia (CLL; choice A) is ruled out by the normal white count, since this type of leukemia is generally associated with an absolute lymphocytosis. Patients with monoclonal gammopathy of undetermined significance (choice B) are generally asymptomatic, although they have a predisposition for subsequently developing myeloma, lymphoma, amyloidosis, or Waldenström's macroglobulinemia. Plasmacytoma (choice D) (solitary myeloma) is a rare, isolated plasma cell neoplasm in bone or soft tissues. If the primary cancer is in bone, it is likely to disseminate; extraosseous tumors tend to remain localized. Since this patient had multiple lytic bone lesions, multiple myeloma is the correct diagnosis. Waldenström's macroglobulinemia (choice E) is a disorder involving neoplasms of lymphocytoid plasma cells that produce monoclonal IgM. Hypergammaglobulinemia produces hyperviscosity of the blood which, along with infiltration by tumor produce the characteristic signs and symptoms. Weakness, weight loss, bone pain, hepatosplenomegaly, and lymphadenopathy occur commonly. A 55-year-old woman complains to her physician that the skin of her armpits and groin "keeps getting darker and darker." Physical examination demonstrates velvety brown and warty skin in the axilla and groin. Biopsy of these lesions shows a variably hyperplastic epidermis with many sharp peaks and valleys. Aside from cosmetic considerations, which of the following is the primary medical significance of these lesions? A. They may be a sign of immunosuppression B. They may be a sign of visceral carcinoma C. They may be easily superinfected D. They may be malignant E. They may be premalignant Explanation: The correct answer is B. The lesions are acanthosis nigricans, which looks somewhat like a mole or wart, but is actually due to epidermal hyperplasia. Acanthosis nigricans can be seen in obesity, diabetes, and in patients with underlying cancers, often adenocarcinomas of the chest or abdomen. The lesions are not characteristic of immunosuppression (choice A) and are not easily superinfected (choice C). They are also neither malignant (choice D) nor premalignant (choice E). A 47-year-old woman undergoes endometrial biopsy because she has had repeated episodes of irregular spotting between periods lately. The biopsy shows strips of endometrium bearing long, narrow, coiled glands lined by a single layer of columnar epithelium showing regular, uniform, small nuclei and clear apical vesicles. Which of the following is the most likely diagnosis? A. Atypical hyperplasia B. Complex hyperplasia without atypia C. Proliferative endometrium 17 D. Secretory endometrium E. Simple hyperplasia Explanation: The correct answer is D. Endometrial biopsies are often performed to evaluate patients with menstrual bleeding abnormalities, particularly in perimenopausal or postmenopausal patients. While the biopsies are done to rule out hyperplasias or cancer, most of the specimens actually show only proliferative or secretory (as in this patient) endometrium. Secretory endometrium has the features noted in the question stem. Atypical hyperplasia (choice A) is characterized by complex glands lined by cells showing features of atypia, such as cytomegaly, increased nuclear cytoplasmic ratio, prominent nucleoli, and increased mitotic index. Complex hyperplasia without atypia (choice B) is characterized by complex, branching glands without cellular atypia. Proliferative endometrium (choice C) is characterized by smaller, noncoiled, glands lined with columnar epithelium without apical (secretory) vesicles. Simple (cystic) hyperplasia (choice E) is characterized by cystically dilated glands without cellular atypia. Which of the following conditions is the most frequent cause of spontaneous abortion in the first trimester of pregnancy? A. Abruptio placentae B. Chorioamnionitis C. Chromosomal abnormalities D. Placenta previa E. Trauma Explanation: The correct answer is C. At least 10% to 15% of normally fertilized and implanted ova are lost in the first trimester of pregnancy because of spontaneous abortion. Studies using immunoassay of human chorionic gonadotropin (hCG) for early diagnosis of pregnancy suggest that the percentage of fertilized ova lost in the first trimester might be even higher. The great majority of these cases are attributable to chromosomal abnormalities. Chromosomal studies are not routinely performed in such cases, but they are recommended when a malformed fetus has been identified or when habitual or recurrent abortions occur. Abruptio placentae (choice A), a complication of the third trimester, occurs when the placenta detaches prematurely from its implantation site. Retroplacental hemorrhage develops within the space between placenta and uterine wall, leading to interruption or severe reduction in the blood supply to the fetus. Chorioamnionitis (choice B), a complication of the second and third trimesters, results from ascending infections through the vaginal canal. Infection of chorioamnionic membranes may lead 18 to premature rupture of membranes and abortion or premature labor. Placenta previa (choice D) is a placenta implanted in the lower segment of the uterus. When dilatation of this segment begins in late pregnancy, a placenta previa may cause severe bleeding and lead to premature labor. Surprisingly, trauma (choice E) is a rare cause of spontaneous abortion. A 65-year-old woman has a long-standing dementing disorder characterized by deterioration in personality, neglect of personal hygiene, impaired judgment, and disinhibited behavior. MRI demonstrates severe cortical atrophy limited to the frontal lobes and anterior two thirds of the temporal lobes, while the remaining cortex is preserved. No evidence of recent or remote infarcts is found. Which of the following diagnoses is most consistent with these pathologic and clinical features? A. Alzheimer disease B. Creutzfeldt-Jacob disease C. Dementia with Lewy bodies D. Frontotemporal dementia E. Vascular dementia Explanation: The correct answer is D. Not all dementing disorders manifest with the same clinical features. Although there is considerable overlap in clinical symptomatology among different types of dementias, making clinical diagnosis somewhat problematic, there are classic presentations that allow identification of a specific form of dementia with a high degree of confidence. In this case, the patient has symptoms due to frontal lobe damage, eg, disinhibition, impaired judgment, and personality changes. Furthermore, MRI demonstrates a specific pattern of cortical atrophy, restricted to the frontal lobes and anterior portion of the temporal lobes. This combination points toward a group of dementias called frontotemporal dementia, the most frequent form of which is Pick disease. Other forms of frontotemporal dementia are very infrequent. Remember: frontal symptoms in conjunction with frontotemporal atrophy = frontotemporal dementia/Pick disease. Alzheimer disease (choice A) is the most frequent form of dementia in industrialized countries. Although symptoms due to frontal damage may be present in Alzheimer disease, they are usually associated with a more generalized impairment of higher neurologic functions, eg, language, memory, and learned movements. In addition, cortical atrophy in Alzheimer disease is widespread and not limited to the frontal and anterior temporal lobes. Creutzfeldt-Jacob disease (choice B) represents the prototype of prion diseases. Cortical atrophy is not a prominent feature of Creutzfeldt-Jacob disease, which manifests with personality changes, memory loss, and seizures, leading to death after a rapid clinical course (a few months to 1 year). Dementia with Lewy bodies, also known as diffuse Lewy body disease (choice C), is one of the most common forms of dementia in Western countries, possibly more common than vascular dementia. It is characterized by widespread formation of Lewy bodies in the substantia nigra, limbic cortex, and subcortical nuclei, such as the basal nucleus of Meynert. Extrapyramidal symptoms similar to Parkinson disease manifest in this form of dementia as a result of degeneration of dopaminergic pathways. 19 Vascular dementia (choice E) is an umbrella term encompassing dementing conditions that arise from pathology of large or small cerebral vessels. It manifests with memory loss associated with focal neurologic symptoms depending on the location of damage. MRI would identify old or recent infarcts, as well as white matter disease. Conditions associated with vascular dementia include the following: Multi-infarct dementia, which is caused by multiple, scattered brain infarcts secondary to atherosclerosis of large arteries of the circle of Willis and/or carotid arteries. Binswanger disease, which involves rarefaction of cerebral white matter and is caused by hypertension-related arteriolosclerosis. Lacunar infarcts, which consist of small (< 1 cm) infarcts in the striatum and thalamus; this condition is related to arteriolosclerosis. Biopsy of a reasonably well-demarcated mass of the nasopharynx demonstrates a plasma cell proliferation. Serum electrophoresis shows a small monoclonal IgG spike. Bone marrow evaluation fails to demonstrate plasma cell proliferation and no lesions are seen on extensive skeletal x-rays. Which of the following is the most likely diagnosis? A. Heavy chain disease B. Monoclonal gammopathy of undetermined significance C. Multiple myeloma D. Plasmacytoma E. Waldenström's macroglobulinemia Explanation: The correct answer is D. Plasmacytoma (solitary myeloma) involving soft tissue (lungs, nasopharynx, nasal sinuses) is a plasma cell proliferation resembling multiple myeloma but without significant metastatic potential. In contrast, some plasmocytomas involving bone eventually (up to 10 to 20 years) develop into frank multiple myeloma. Heavy chain diseases (choice A) constitute a group of rare lymphoplasmacytic malignancies in which excessive amounts of a defective heavy immunoglobulin chain are produced. They may take the form of gamma heavy-chain disease (from IgG), alpha heavy-chain disease (from IgA) or mu heavy-chain disease (from IgM); malignant cells are usually present in marrow in all of these conditions. Monoclonal gammopathy of undetermined significance (choice B) is a disease of elderly patients with a monoclonal spike on serum or urine electrophoresis, but no identifiable mass or bone marrow lesion; 20% of these patients eventually develop one of the other diseases listed in the answer choices. Multiple myeloma (choice C) is a malignancy derived from a single plasma cell clone with significant metastatic potential. Multiple lytic bone lesions are usually seen. Waldenström's macroglobulinemia (choice E) is a malignancy of lymphoplasmacytic cells that secrete IgM. In this disorder, the bone marrow is diffusely rather than focally infiltrated by lymphocytes, plasma cells, and hybrid forms. A 65-year-old woman presents with a 30-lb weight loss and malaise. Cancer is suspected. Which of the following is the correct list, starting with the most prevalent, of the three most common causes of cancer in women? A. Breast, lung, colon and rectum 20 B. Breast, uterus, lung C. Colon and rectum, lung, ovary D. Lung, breast, ovary E. Ovary, uterus, lung Explanation: The correct answer is A. The correct female incidence sequence is breast (32%), lung (13%), and colon and rectum (13%). The two major causes of cancer death in women are lung (23%) and breast (18%). In men, the incidence sequence is prostate (32%), lung (16%), and colon and rectum (12%). The two leading causes of male cancer deaths are lung (33%) and prostate (13%). The uterus and ovary (choices B, C, D, and E) are not among the three organs most frequently affected by cancer in women. A 50-year-old woman presents with a 5-year history of headaches, generalized tonic-clonic seizures, and bilateral leg weakness. Skull films reveal hyperostosis of the calvarium. Biopsy of the responsible lesion shows a whorling pattern of the cells. Which of the following is the most likely diagnosis? A. Arachnoid cyst B. Glioblastoma multiforme C. Meningioma D. Metastatic breast cancer E. Oligodendroglioma Explanation: The correct answer is C. The most likely diagnosis is an intracranial meningioma. Meningiomas are slow-growing, benign tumors comprising 15% of intracranial tumors; they are most common in the elderly. They originate from either dura mater or arachnoid and are sharply demarcated from brain tissue. Meningiomas often incite an osteoblastic reaction in the overlying cranial bones. Microscopically, the meningioma cells have a tendency to encircle one another, forming whorls and psammoma bodies. Clinically, they present as mass lesions; seizures may occur. The superior parasagittal surface of the frontal lobes is a favorite site of origin. This can often produce leg weakness, since the leg motor fibers that pass down through the internal capsule originate in parasagittal cortical regions. Treatment of meningiomas is usually surgical. Arachnoid cysts (choice A) are formed by splitting of the arachnoid membrane; most arachnoid cysts arise near the Sylvian fissure. They may present with mass effect, but would be unlikely to produce seizures, prominent focal signs, or reactive hyperostosis. Glioblastoma multiforme (choice B) is an aggressive malignant astrocytoma that would likely have killed the patient long before 5 years had elapsed. Metastatic breast cancer (choice D) would generally look different microscopically (the whorling cell pattern is characteristic of meningioma). It would be unlikely for metastatic cancer to cause a reaction in the overlying bone, or to be present long enough to cause 21 symptoms for 5 years. Oligodendrogliomas (choice E) are glial tumors that could produce the described clinical picture, but usually do not cause hyperostosis of the calvarium or exhibit the characteristic whorling cell pattern microscopically. When a histologic section is taken of an abscess, many of the observed neutrophils show a degenerative change in which the nucleus has undergone fragmentation. This process is known as A. caseous necrosis B. coagulative necrosis C. karyolysis D. karyorrhexis E. pyknosis Explanation: The correct answer is D. Karyorrhexis refers to a pattern of nuclear degradation in which a pyknotic or partially pyknotic nucleus undergoes fragmentation followed by complete lysis. This pattern is common in the neutrophils present in acute inflammation. The type of necrosis seen in an abscess is liquefactive necrosis. Caseous necrosis (choice A) is seen in tuberculosis and some other granulomatous diseases; coagulative necrosis (choice B) is seen following infarctions of many organs (other than the brain). Karyolysis (choice C) is also a degenerative change affecting nuclei. In this case, however, it is seen as a decrease in nuclear basophilia, which is presumably the result of DNAse activity. Pyknosis (choice E) is characterized by nuclear shrinking and basophilia, apparently as a result of DNA condensation. A 52-year-old woman has recently undergone a breast resection for carcinoma. Based on the statistics for breast cancer incidence, which of the following types of carcinoma does this patient most likely have? A. Colloid (mucinous) B. Invasive ductal C. Invasive lobular D. Medullary E. Metastatic bronchogenic Explanation: The correct answer is B. Invasive ductal carcinoma is the most likely candidate. Of the various types of breast adenocarcinoma, invasive ductal carcinoma is by far the most common variant, accounting for approximately 75% to 80% of all invasive breast carcinomas. Invasive ductal carcinoma develops from epithelial cells of the terminal duct. Histologically, it is composed of small, glandular, ductlike structures, lined by variably anaplastic cells. The most common 22 mode of presentation is a palpable mass in the breast. Its prognosis depends mostly on staging (spread of cancer) rather than grading (degree of differentiation). The colloid (mucinous) variant (choice A) is relatively rare (about 1% to 2%) and occurs more frequently in older women. Histologically, this carcinoma is characterized by abundant mucin secretion. It is associated with a better prognosis than the ductal type. Invasive lobular carcinoma (choice C) is the second most frequent histologic type of breast adenocarcinoma, accounting for approximately 10% of all cases. Its presumed cell of origin is the lobular cell. The most typical histologic characteristic is the presence of cancer cells lined up in orderly rows ("single-file"). Medullary carcinoma (choice D) tends to occur in younger women and is associated with a slightly better prognosis. Although a malignant tumor, medullary carcinoma is well circumscribed and surrounded by a florid lymphoplasmacytic reaction. The name is due to its soft consistency. Metastatic cancer may involve the breast like any other organ. Bronchogenic carcinoma (choice E) may also spread to the breast by lymphatic route or by contiguity, but this would be less likely than primary breast cancer. A 55-year-old man is brought to his physician's office with a 3-month history of progressive mental deterioration in the form of memory loss, mood changes, and errors in judgment. His gait is unsteady, and he requires assistance to prevent falling. He has no history of seizures, head trauma, or incontinence. Computed tomography (CT) scan and lumbar puncture are unremarkable. Physical examination reveals hypertonicity of all extremities, bilateral equivocal plantar response, ataxic gait, and myoclonic jerks in the lower extremities. What is the mechanism by which this infectious agent causes its pathology? A. Amyloid deposition B. Autoimmune destruction C. Chronic inflammation D. Embolization and infarction E. Toxin production Explanation: The correct answer is A. This is the classic presentation of Creutzfeldt-Jacob disease (CJD). Although the pathogenesis is incompletely understood, these patients develop extracellular deposition of abnormal fibrillar proteins in the brain, ie, amyloid. Autoimmune destruction (choice B) is not indicated because there is no immunologic response to the deposition of these extracellular proteins; thus there is no chronic inflammation (choice C) Although embolization and infarction (choice D) could complicate the presentation in the age group typically afflicted with CJD, these processes are not believed to have any direct role in this pathology. No toxin is produced (choice E) to account for the presentation in CJD. A patient consults a dermatologist about a skin lesion on her neck. Examination reveals a 1-cm diameter, 23 red, scaly plaque with a rough texture and irregular margins. Biopsy demonstrates epidermal and dermal cells with large, pleomorphic, hyperchromatic nuclei. Which of the following conditions would most likely predispose this patient to the development of this lesion? A. Actinic keratosis B. Compound nevus C. Dermal nevus D. Junctional nevus E. Melanoma Explanation: The correct answer is A. The lesion is a squamous cell carcinoma of the skin. Actinic keratosis, which is a hyperplastic lesion of sun-damaged skin, predisposes for squamous cell carcinoma. Another predisposing condition to remember is xeroderma pigmentosum, which predisposes for both squamous cell and basal cell carcinomas of skin. A nevus is a mole, containing characteristic cells called nevocellular cells. If the nevocellular cells are located at the dermal-epidermal junction (junctional nevus, choice D), in the dermis (dermal nevus, choice C), or both (compound nevus, choice B), they do not predispose for squamous cell carcinomas of the skin. Malignant melanoma (choice E), however, can arise in pre-existing nevi. A 24-year-old woman gives birth to an apparently normal infant. The neonate begins feeding well by the second day, then at ten days, suddenly develops gastrointestinal obstruction. Which of the following is the most likely cause of this presentation? A. Adhesions B. Congenital pyloric stenosis C. Hirschsprung's disease D. Intussusception E. Volvulus Explanation: The correct answer is D. All of the conditions listed can cause gastrointestinal obstruction, but the clinical presentation is most suggestive of intussusception. In intussusception, there is telescoping of one bowel segment into another, more distal segment. The disorder is relatively common in infants and children due to the poor support offered by their thin mesentery. Intussusception produces intestinal obstruction, and it may produce bowel ischemia or infarction by trapping mesenteric vessels along with the affected segment. In some cases, the intussusception may be reduced by diagnostic barium enema. Adhesions (choice A) can cause bowel obstruction following surgery or inflammatory bowel diseases. Congenital pyloric stenosis (choice B) typically presents as projectile vomiting in a 3-4 week old baby. 24 Hirschsprung's disease (choice C), caused by absence of ganglion cells in the distal bowel, is usually diagnosed in the first few days of life when there is a failure to pass meconium. Volvulus (choice E) is due to rotation of bowel segments. This is usually a disease of the elderly. A middle-aged man with a long history of sexual activity slowly develops testicular enlargement. Needle biopsy demonstrates the presence of obliterative endarteritis with perivascular cuffing of lymphocytes and plasma cells. A diffuse interstitial inflammation with edema and prominent plasma cell infiltrate is also present. Which of the following is the most likely diagnosis? A. Gonorrhea B. Mumps C. Nonspecific orchitis D. Syphilis E. Tuberculosis Explanation: The correct answer is D. This is one presentation of syphilis, which can involve the testis and epididymis in both the acquired and congenital types of the disease. Characteristically, the testis is usually involved before the epididymis. Microscopically, the testis may show either gumma formation or the findings described in the question stem. Gonorrhea (choice A) usually causes an acute epididymitis and orchitis with prominent neutrophils. Mumps orchitis (choice B) would usually be accompanied by parotitis. Nonspecific orchitis (choice C) is characterized by prominent neutrophils. Tuberculosis orchitis (choice E) is characterized by granulomas with acid-fast bacteria. A 70-year-old woman dies in a nursing home after a heart attack. The time of onset of her clinical symptomatology and the cause of death are uncertain; furthermore, the possibility of neglect is being considered. Therefore, an autopsy investigation is arranged. The forensic pathologist discovers acute thrombosis involving the posterior descending branch of the right coronary artery with resultant myocardial infarction (MI) in the posterior third of the interventricular septum. Histologically, there is coagulation necrosis with associated abundant neutrophilic infiltration. Histiocytes and lymphocytes are scanty. Which of the following is the approximate period between the onset of pain (ie, beginning of ischemic injury) and death? A. 1 hour B. 12 hours C. 2 days D. 5 days E. 10 days 25 Explanation: The correct answer is C. Following irreversible ischemic injury, the heart (and any other organ) displays an orderly sequence of events that progresses from necrosis of parenchymal cells to inflammatory reaction, granulation tissue, and scar healing. Although ischemic injury manifests with pain almost immediately following vascular occlusion, histologic evidence of necrosis lags behind the clinical symptoms. At 1 hour (choice A) after ischemia, there is no morphologic change indicative of necrosis. The first signs of necrosis appear 12 hours (choice B) after irreversible ischemia: myocytes appear intensely eosinophilic and wavy, but there is no inflammatory reaction yet. Acute inflammatory cells (neutrophils) infiltrate the infarcted area beginning 1 day and peaking at approximately 2-3 days after injury. This acute inflammatory response partially overlaps with the subsequent influx of lymphocytes and histiocytes. Reabsorption of necrotic myofibers by histiocytes, as well as proliferation of small blood vessels, marks early formation of granulation tissue at around 5 days (choice D). Granulation tissue is advanced at 10 days (choice E) and consists of fibroblasts, small blood vessels, and residual chronic inflammatory cells within a matrix of young collagen matrix. A 54-year-old man presents with a chief complaint of "burning" abdominal pain in the epigastric region. Endoscopy demonstrates a well-defined, regular gastroesophageal junction located 3 cm above the esophageal hiatus in the diaphragm. Biopsy of the distal side of the junction demonstrates normal gastric mucosa. This lesion is best classified as which of the following? A. Achalasia B. Esophageal ring C. Esophageal web D. Paraesophageal hernia E. Sliding hernia Explanation: The correct answer is E. This patient has a sliding hiatal hernia, which is the most common (90%) form of hiatal hernia. This condition is frequently associated with gastric reflux. Achalasia (choice A) is actually a physiologic, rather than an anatomic variation. In this disorder, the lower esophageal sphincter fails to relax adequately, and esophageal peristalsis is often abnormal. Esophageal rings (choice B) are mucosal folds in the esophagus. They are called esophageal webs (choice C) in the upper esophagus. Schatzki rings are mucosal rings in the lower esophagus, at the gastroesophageal junction. In a paraesophageal hernia (choice D), an area of gastric cardia rolls along with the esophagus through an incompetent hiatus into the thorax. In a paraesophageal hernia, the gastroesophageal junction would not be displaced. Which of the following pulmonary conditions is associated with widespread formation of hyaline membranes in the alveolar cavities? 26 A. Asthma B. Bacterial pneumonia C. Desquamative interstitial pneumonitis D. Diffuse alveolar damage E. Hemodynamic pulmonary edema Explanation: The correct answer is D. Diffuse alveolar damage, clinically referred to as adult respiratory distress syndrome (ARDS), is characterized by diffuse damage to the alveolar/capillary barrier, which may result from diverse acute conditions. The four most frequent causes are trauma, sepsis, shock, and gastric aspiration. The pathogenesis is not entirely clear, but influx of neutrophils and release of cytokines, eicosanoids, and free radicals seem to be crucial in promoting alveolar damage. The most characteristic histopathologic hallmark of diffuse alveolar damage is formation of hyaline membranes within the alveolar cavities. These consist of proteinaceous material of plasma origin and necrotic debris from desquamated epithelium. The condition has a 60% mortality and manifests with acute respiratory failure. The pathologic features of asthma (choice A) are relatively nonspecific and are similar, for example, to those of chronic bronchitis, including chronic inflammatory infiltration, hyperplasia of mucous glands, and hypertrophy of smooth muscle. The presence of numerous eosinophils, however, is more characteristic of asthma. Bacterial pneumonia (choice B) is characterized by intra-alveolar exudation of neutrophils, fibrin, and erythrocytes. Bacteria are also present within the alveolar cavities. Desquamative interstitial pneumonitis (DIP) (choice C) is a form of interstitial disease referred to as idiopathic pulmonary fibrosis. In contrast to usual interstitial pneumonitis (another form of idiopathic pulmonary fibrosis), DIP is more responsive to steroid treatment. Histopathologically, DIP leads to hyperplasia of pneumocytes and accumulation of histiocytes that fill the alveolar cavities. Hemodynamic pulmonary edema (choice E) is caused by increased hydrostatic pressure, as occurs in acute left ventricular failure. It is due to escape of fluid from the intravascular compartment into the alveoli. A baby is born with a flat facial profile, prominent epicanthal folds, and simian crease. She vomits when fed, and upper GI studies demonstrate a "double bubble" in the upper abdomen. Which of the following cardiovascular abnormalities might this child also have? A. Atrial septal defect B. Berry aneurysm C. Coarctation of the aorta D. Endocardial cushion defect E. Tetralogy of Fallot Explanation: 27 The correct answer is D. The disease is Down syndrome (trisomy 21). In addition to mental retardation and the characteristic physical findings described in the question stem, duodenal atresia is fairly common, as evidenced by the "double bubble" sign on x-ray. These children are also likely to have various cardiac anomalies; endocardial cushion defect is the most common. Atrial septal defect (choice A) is one of the most common genetic defects in the general population, but is less common than endocardial cushion defect in patients with Down syndrome. Berry aneurysms (choice B), also known as saccular aneurysms, are typically located in the circle of Willis on the ventral surface of the brain. They occur more frequently in patients with adult polycystic disease. Rupture can produce subarachnoid hemorrhage. Coarctation of the aorta (choice C) occurs more commonly in females with a 45, XO genotype (Turner syndrome). Tetralogy of Fallot (choice E) is the most common cause of early cyanosis, consisting of a ventricular septal defect, right ventricular outflow tract obstruction, an overriding aorta, and right ventricular hypertrophy. 0 - ArchivalUser - 05-12-2009 dont' worry about it...can't thank you enough...i was too lazy to do questions...but did all 40, poSSIBLY.. 0 - ArchivalUser - 05-12-2009 THE NUMBERS THAT U SEE SOME TIMES ARE PG NUMBERS IGNORE THEM.... SORRY GUYS I KNOW IT IS KINDA MESS. I WILL SOON THINK OF SOME BETTER WAY ...AND I REALLY HOPE THAT U GUYS GIVE SOME SORT OF INPUT INTO IT SO WE CAN MAKE IT MORE EFFECTIVE AND ENJOYABLE AND GET EVERY ONE INVOLVED. THANKS AND GOOD NITE. 0 - ArchivalUser - 05-12-2009 Do you think that these questions represent the spirit of the real step 1 ? please give us an answer guys out of your experience and opinions 0 - ArchivalUser - 05-12-2009 I am still in the process.... i probably know lot less than u do... what I think of the questions is just a way to ask ourself ...."do i really understand this topic"?.... if yes than good if not ....go and hit the books and make sure that section is really understood well. But reading is crucial till the very last day.... Questions and reading combined is the best..... morning for reading ...afternoons for questions.... 0 - ArchivalUser - 05-12-2009 what way were you thinking of doc? i can't think of any other way these questions cud be as fun. 0 - ArchivalUser - 05-12-2009 Okay, i totally agree ... but what i mean, are these questions representative of the spirit of the real exam, or is the real exam usually harder than this ? I never solved questions thats why i am asking 0 - ArchivalUser - 05-12-2009 chessmaster....it all depends on your luck really.. i've heard of ppl getting easy questions, and some..not so much. but to answer your questions...you woudln't know 'til you take the exam yourself. do the nbmes hope it helped, and didn't make you run in circles 0 - ArchivalUser - 05-12-2009 i would say exam is not harder than this. It is just the way it is written. if u pay close attention to each question...all the clues are there to ans the question. I would consider it to be good comparison to the exam. 0 - ArchivalUser - 05-12-2009 hehehe ... thanks for everything ... When do you start studying in the morning ??? |