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Abstract Pancreatic mucinous cystic neoplasm (MCN) has two histological components: tumor epithelia and ovarian-like stroma (OLS). To examine the progression and changes in pancreatic MCNs, we analyzed the distribution, amount, immunohistochemical phenotype, presence of theca cells of OLS, and tumor epithelium in 45 surgically resected MCN cases, comparing them with tumor sizes. The OLS data of female MCN cases were also compared between those who were ≤ 51 years old and those > 51 years old to see the effect of menopause on MCN histology. Non-mucinous type epithelium was present in all low-grade MCNs, but its ratio decreased with tumor size (p 51 years than those ≤ 51 years old, however it did not reach statistical significance. This is the first study to show the intralobular distribution of OLS.

Schwannomas of the colon are rare and difficult to diagnose preoperatively. We report a case of schwannoma of the ascending colon that was resected laparoscopically. A 64-year-old woman was referred to our hospital by her local clinic for further evaluation and management of a submucosal tumor of the ascending colon. A definitive preoperative diagnosis could not be reached despite examinations. Gastrointestinal stromal tumor, leiomyoma and lymphoma were the differential diagnoses. We performed a laparoscopic right hemicolectomy with D2 lymph node dissection. Histological findings with hematoxylin-eosin staining revealed spindle-like tumor cells, and immunohistochemical analysis showed that the tumor was positive for S-100 but negative for c-kit, CD34, smooth muscle actin and desmin, with a Ki-67 index of

Background/Purpose The role of the ampullary mucosa, especially its distended glands at the papilla of Vater, has not been fully explored. Methods Twenty-nine pancreatoduodenectomized specimens from pancreatobiliary diseases and 44 autopsied cases, as controls, were studied histopathologically and immunohistochemically. Results In 12 out of the 29 pancreatoduodenectomized cases the ampullary mucosa was in contact with the duodenal mucosa just at the outlet of the ampulla. In the remaining 17 cases, the ampullary mucosa overgrew beyond the ostium, replacing a portion of the surrounding duodenal mucosa, termed “distended glands,” which measured an average of 1532?µm in length. The muscularis mucosae of the duodenum and the Oddi’s sphincter muscle merged in an “end-to-end, sharp-angled” manner at the ostium in the former, whereas this occurred in an “end-to-side, less sharp, rather right-angled” manner in the latter. Immunohistochemically, the distended glands in some cases showed negative/weakly positive staining for anti-carbohydrate antigen (CA) 19-9 and a high proliferation index evaluated using Ki67. In the autopsied materials, distended glands were found in 24 out of the 44 cases. Conclusions Distended glands of the ampullary mucosa were frequently found and only grew on the Oddi’s sphincter muscle extension. They may represent not only malignant change but also an adaptive phenomenon for bile and pancreatic juice flow. [ABSTRACT FROM AUTHOR]

Primary liposarcoma of bone is exceedingly rare. We report a case of primary pleomorphic liposarcoma in the humerus of a 38-year-old female. Radiographs demonstrated an expansile and osteolytic lesion extending from the head to the proximal part of the shaft in the right humerus. MR study showed a defined lesion in the humerus. The lesion had an iso-signal intensity and partial high-intensity lesion on T1-weighted images and a heterogeneous high signal intensity on T2-weighted images. Wide resection and proximal humeral endoprosthesis replacement were performed. Final pathological diagnosis of the lesion was pleomorphic liposarcoma. This is the second reported case of pleomorphic liposarcoma of the bone, and the first case presenting MRI findings for liposarcoma of bone. [ABSTRACT FROM AUTHOR]