title: Pseudopapillary solid cystic tumor arising from an extrapancreatic site.
abstract: A case of pseudopapillary solid cystic tumor arising in the omentum of a 46-year-old woman is presented. A well-defined, encapsulated tumor measuring 5.2 x 4.0 x 4.0 cm was histologically characterized by a combination of solid and pseudopapillary growth patterns of tumor cells with abundant pale-to-eosinophilic cytoplasm. No pancreatic tissue was observed within or adjacent to the tumor. Immunohistochemically, the tumor was positive for vimentin, epithelial membrane antigen, and alpha1-antichymotrypsin. Ultrastructurally, the tumor cells contained electron dense granules of variable sizes, most likely representing lysosomes. Flow cytometry showed a diploid DNA content with a high S-phase fraction. The patient was well without recurrence 3 months after diagnosis. It is important to include pseudopapillary solid cystic tumor in the differential diagnosis of omental tumors.
authors.affiliation: Department of Pathology, The Jikei University School of Medicine, Tokyo, Japan. maasafu@jikei.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Fukunaga
mesh_terms: D018292:Cystadenoma, Papillary / Q000737:chemistry / Q000473:pathology*; D003593:Cytoplasm / Q000473:pathology; D003594:Cytoplasmic Granules / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D008875:Middle Aged; D018396:Mucin-1 / Q000032:analysis; D009852:Omentum / Q000737:chemistry / Q000473:pathology*; D010534:Peritoneal Neoplasms / Q000737:chemistry / Q000473:pathology*; D014746:Vimentin / Q000032:analysis; D000514:alpha 1-Antichymotrypsin / Q000032:analysis
chemical_list: D018396:Mucin-1; D014746:Vimentin; D000514:alpha 1-Antichymotrypsin