[A Case of Duodenal Adenocarcinoma in the Third Portion Treated with Partial Duodenectomy].

A 85-year-old man was admitted due to vomiting. Abdominal CT showed the remarkable expansion of the stomach and the stenotic lesion in the third portion of the duodenum. Duodenal endoscopy showed a circular tumor of the third potion of the duodenum, and biopsy disclosed tubular adenocarcinoma. Operation was performed on the basis of a diagnosis of primary duodenal cancer of the third portion. Liver metastasis, peritoneal dissemination, and apparent lymph node enlargement were not observed. The tumor was present in the third portion of the duodenum and partial duodenectomy was performed. Reconstruction was achieved by side to side anastomosis of the duodenum and the jejunum. Histopathological diagnosis was well differentiated tubular adenocarcinoma, SS, ly1, v1. Primary duodenal cancer is a relatively rare disease, and there are few cases of third portion. If pancreatic invasion and lymph node metastasis are not observed as in this case, it is necessary to examine the indication of partial duodenectomy.

Utility and pitfalls of immunohistochemistry in the differential diagnosis between epithelioid mesothelioma and poorly differentiated lung squamous cell carcinoma.

AIMS: The aims of this study were to clarify the usefulness of immunohistochemistry in the differential diagnosis of epithelioid mesothelioma with a solid growth pattern [solid epithelioid mesothelioma (SEM)] and poorly differentiated squamous cell carcinoma (PDSCC), and to confirm the validity of a specific type of antibody panel. Additionally, we aimed to clarify the pitfalls of immunohistochemical analyses. METHODS AND RESULTS: Formalin-fixed paraffin-embedded specimens from 36 cases of SEM and 38 cases of PDSCC were immunohistochemically examined for calretinin, podoplanin (D2-40), Wilms' tumour gene product (WT1), cytokeratin (CK) 5/6, p40, p63, carcinoembryonic antigen (CEA), epithelial-related antigen (MOC31), claudin-4, thyroid transcription factor-1 (TTF-1), and napsin A. WT1 showed the highest diagnostic accuracy (85.1%) as a mesothelial marker, and CEA, p40 and claudin-4 showed higher diagnostic accuracies (95.9%, 94.6%, and 93.2%, respectively) as carcinoma markers. Calretinin (diagnostic accuracy: 75.7%), D2-40 (diagnostic accuracy: 67.6%), CK5/6 (diagnostic accuracy: 63.5%), TTF-1 (diagnostic accuracy: 55.4%) and napsin A (diagnostic accuracy: 52.7%) could not differentiate between SEM and PDSCC. Among these markers, the combination of calretinin and WT1 showed the highest diagnostic accuracy (86.5%) as a positive marker, and the combination of p40 and CEA showed the highest diagnostic accuracy (97.3%) as a negative marker. The combination of CEA and claudin-4 also showed relatively high diagnostic accuracy (94.6%) as a negative marker. CONCLUSIONS: We recommend the combination of WT1 and calretinin as a positive maker, and the combination of CEA and claudin-4 as a negative marker, for differential diagnoses of SEM and PDSCC.