Combined adenomatoid tumor and well differentiated papillary mesothelioma of the omentum.
Herein is reported a highly rare case of combined adenomatoid tumor and well differentiated papillary mesothelioma of the omentum. A 45-year-old Japanese man was incidentally found to have a mesenteric mass during abdominal ultrasonography. Grossly, a well-circumscribed and non-encapsulated tumor, measuring 24 × 23 × 22 mm, was located in the omentum with no obvious invasion to the surrounding stomach and pancreas. Microscopically, the tumor consisted of two histological distinct components; the majority of it showed irregular arrangement of numerous cysts lined by a single layer of flattened or epithelioid cells and the multifocal minor component exhibited prominent papillary protrusions lined by a single layer of cuboidal cells with relatively uniform nucleus. Immunohistochemically, the tumor cells were diffusely positive for cytokeratin (AE1/AE3), vimentin, calretinin, D2-40 and WT-1, and negative for epithelial membrane antigen (EMA), desmin, S-100 protein and CD68. Ki-67 labeling index of the tumor cells was <5%. The postoperative course was uneventful, though he has not received any adjuvant therapy. Despite the rarity, recognition of such combined cases of mesothelial lesions is important to prevent overdiagnosis.
Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu, Japan. yuha@gifu-u.ac.jp
Yuichiro
Y
Hatano
Yoshinobu
Y
Hirose
Kengo
K
Matsunaga
Yusuke
Y
Kito
Ichiro
I
Yasuda
Hisataka
H
Moriwaki
Shinji
S
Osada
Kazuhiro
K
Yoshida
Akira
A
Hara
D018254:Adenomatoid Tumor / Q000473:pathology* / Q000601:surgery; D014408:Biomarkers, Tumor / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008654:Mesothelioma / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000473:pathology* / Q000601:surgery; D009852:Omentum / Q000473:pathology*; D010534:Peritoneal Neoplasms / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome
D014408:Biomarkers, Tumor