Anti-Cytokeratin monoclonal antibody, clone MQ35

Background: Squamous cell carcinomas (SqCCs) of the lung are known to arise more often in a central area but reports of peripheral SqCCs have increased, with a pathogenesis that is obscured. In this study, the clinicopathologic characteristics of peripheral lung SqCCs were studied and compared with those of the central type. Methods: This study included 63 peripheral lung SqCCs and 48 randomly selected central cases; hematoxylin and eosin-stained slides of surgically resected specimens were reviewed in conjunction with radiologic images and clinical history. Cytokeratin-7 irnmunohistochemical staining of key slides and epidermal growth factor receptor (EGFRYKRAS mutations tested by DNA sequencing were also included. Results: Stages of peripheral SqCCs were significantly lower than central SqCCs (p=016). Cystic change of the mass (p=007), presence of interstitial fibrosis (p=0.007), and anthracosis (p=.049) in the background lung were significantly associated with the peripheral type. Cytokeratin-7 positivity was also higher in peripheral SqCCs with cutoffs of both 10% and 50% (p=011). Pathogenic mutations in EGFR and KRAS were observed in only one case out of the 72 evaluated. The Cox proportional hazard model indicated a significantly better disease-free survival (p=009) and the tendency of better overall survival (p=106) in the peripheral type. Conclusions: In peripheral type, lower stage is a favorable factor for survival but more frequent interstitial fibrosis and older age are unfavorable factors. Multivariate Cox analysis revealed that peripheral type is associated with better disease-free survival. The pathogenesis of peripheral lung SqCCs needs further investigation, together with consideration of the background lung conditions.

Background Biliary metastasis of colorectal cancer is a manifestation of metastatic liver carcinoma, and is often difficult to differentiate from cholangiocarcinoma. Further, lower bile duct metastasis of colorectal cancer is rare. We report the case of a 74-year-old woman who underwent pylorus-preserving pancreatoduodenectomy for lower bile duct metastasis of rectal cancer. Case presentation The patient had undergone laparoscopic low anterior resection for rectal cancer (pT3N0M0 stage IIA) 6 years ago, laparoscopic anterior liver resection for liver metastasis (Couinaud segment V) 3 years ago, and left and caudal lobectomy with extrahepatic bile duct resection for left intrahepatic bile duct metastasis 6 months ago. A follow-up examination showed a 15 mm mass in the common bile duct, for which she underwent pylorus-preserving pancreatoduodenectomy. Histological and immunohistological examination of the specimens revealed similar cytokeratin (CK) expression patterns, which were negative for CK7 and positive for CK20. Therefore, the definitive diagnosis was metastasis from rectal cancer. Conclusions In summary, we encountered a case of lower bile duct metastasis from rectal cancer, which is often difficult to differentiate from cholangiocarcinoma. In such patients, CK7 and CK20 expression patterns are important in differentiating the two. The mechanism of metastasis in this case was considered to be through cancer cell implantation from lymphatic spread, or through distant metastasis of the primary cancer.