Inflammatory fibroid polyp in the duodenum of a common marmoset (Callithrix jacchus).
A 32-month-old male common marmoset had a firm and white-colored mass in the duodenal wall. The cut surface was smooth and grayish white in color. Histologically, the mass consisted of a proliferation of spindle cells with an oval to spindle-shaped nucleus and scant eosinophilic cytoplasm in a loose myxoid or fibrotic background. Most of the lesion displayed no specific growth pattern whereas some of the cells concentrated around the vessels and created an onion-bulb structure. Additionally, marked inflammatory cellular infiltration, mainly eosinophils, was observed throughout the lesion. Immunohistochemically, the spindle cells were positive for vimentin, α-smooth muscle actin, fascin, and cyclin D1, and negative for S-100, factor VIII-related antigen, and c-kit. These histological and immunohistochemical features did not meet any differential diagnoses such as gastrointestinal stromal tumor, inflammatory myofibroblastic tumor, solitary fibrous tumor/hemangiopericytoma, smooth muscle tumor, schwannoma, and hemangiosarcoma. Collectively, the authors diagnosed the mass as a lesion that corresponded to an inflammatory fibroid polyp (IFP) in humans. IFP is defined as a mesenchymal proliferation composed of spindle stromal cells, small blood vessels, and inflammatory cells, particularly eosinophils, and is currently classified as a nonneoplastic lesion. To the best of our knowledge, this is the first case of spontaneous IFP in nonhuman primates.
Medicinal Safety Research Laboratories, Daiichi-Sankyo Co., Ltd., Tokyo, Japan. yokouchi.yusuke.uw@daiichisankyo.co.jp
Yusuke
Y
Yokouchi
Masako
M
Imaoka
Ayako
A
Sayama
Toshimasa
T
Jindo
Atsushi
A
Sanbuissho
D000199:Actins / Q000378:metabolism; D000818:Animals; D002144:Callithrix; D002352:Carrier Proteins / Q000378:metabolism; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000378:metabolism; D004378:Duodenal Diseases / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D004386:Duodenum / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D007417:Intestinal Polyps / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism; D008992:Monkey Diseases / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D014746:Vimentin / Q000378:metabolism
D000199:Actins; D002352:Carrier Proteins; D008840:Microfilament Proteins; D014746:Vimentin; D019938:Cyclin D1; C020324:fascin