04-17-2009, 09:00 AM
A 60-year-old man who is being evaluated for abdominal pain and a 30-pound weight loss undergoes
endoscopy, which demonstrates a broad region of the gastric wall in which the rugae are
flattened. Biopsy of this area shows infiltration by numerous polygonal tumor cells with small,
dark, round or ovoid nuclei pushed to the margin of the cell by large, clear, cytoplasmic
structures. These cells might be expected to have which of the following properties?
A. Keratohyalin granules observed by electron microscopy
B. Melanosomes and premelanosomes by electron microscopy
C. Positive staining for gastrin by light microscopy
D. Positive staining for leukocyte common antigen by light microscopy
E. Positive staining for mucin by light microscopy
endoscopy, which demonstrates a broad region of the gastric wall in which the rugae are
flattened. Biopsy of this area shows infiltration by numerous polygonal tumor cells with small,
dark, round or ovoid nuclei pushed to the margin of the cell by large, clear, cytoplasmic
structures. These cells might be expected to have which of the following properties?
A. Keratohyalin granules observed by electron microscopy
B. Melanosomes and premelanosomes by electron microscopy
C. Positive staining for gastrin by light microscopy
D. Positive staining for leukocyte common antigen by light microscopy
E. Positive staining for mucin by light microscopy