title: Malignant neuroendocrine tumor of the jejunum with osteoclast-like giant cells. Enzyme histochemistry distinguishes tumor cells from giant cells.
abstract: We report a case of a neuroendocrine tumor of the jejunum metastatic to the liver in a 26-year-old woman. Light and electron microscopy of this tumor revealed a poorly differentiated neoplasm composed of clusters of round to polygonal cells compatible with a diagnosis of neuroendocrine tumor. In the absence of identifiable silver-staining granules or immunocytochemical demonstration of a specific hormone product in tumor cells, this tumor cannot be further classified among the various neuroendocrine tumors that may arise in this location. However, interspersed among tumor cells was a distinct population of multinucleate giant cells having an appearance similar to benign osteoclasts. Enzyme histochemistry for 5'-nucleotidase, acid phosphatase, and nonspecific esterase each showed a dichotomous staining pattern for the small tumor cells and giant cells and suggest that the giant cells are not tumor derived, but represent a second, presumably reactive, cell population.
authors.forename: C E
authors.initials: CE
authors.lastname: Alpers
authors.forename: J H
authors.initials: JH
authors.lastname: Beckstead
mesh_terms: D015720:5'-Nucleotidase; D000135:Acid Phosphatase / Q000032:analysis; D000328:Adult; D000469:Alkaline Phosphatase / Q000032:analysis; D003937:Diagnosis, Differential; D005260:Female; D005870:Giant Cell Tumors / Q000473:pathology*; D006801:Humans; D007580:Jejunal Neoplasms / Q000201:enzymology / Q000473:pathology*; D007583:Jejunum / Q000473:pathology*; D008113:Liver Neoplasms / Q000556:secondary; D008854:Microscopy, Electron; D009708:Nucleotidases / Q000032:analysis; D010010:Osteoclasts / Q000473:pathology*; D013194:Staining and Labeling
chemical_list: D009708:Nucleotidases; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D015720:5'-Nucleotidase