Small cell carcinoma of the extrahepatic bile duct: Case report and immunohistochemical analysis

Abstract

A small cell carcinoma of the extrahepatic bile duct in a 75-year-old Japanese man is reported. The patient suffered from obstructive jaundice, and percutaneous transhepatic cholangiography-drainage (PTCD) revealed a massive lesion in the lower common bile duct. Because it was diagnosed as a malignant tumor, pancreaticoduodenectomy was performed. A nodular infiltrating tumor measuring 4.5 x 3.0 x 2.0 cm was located in the intrapancreatic portion of the extrahepatic bile duct. Histologically, the tumor was composed of a dense proliferation of small atypical cells with a little region of high-grade dysplasia in the adjacent epithelium of the common bile duct. Tumor cells were immunoreactive to neuroendocrine markers such as chromogranin A, synaptophysin, CD56, and Leu7. Although carcinoma cells invaded into pancreas and duodenum, there were no histological findings that indicated the carcinoma arose from the mucosa of either the pancreatic duct or duodenum. These results indicated that the tumor was a small cell carcinoma derived from the epithelium of the extrahepatic bile duct; a rare neoplasm with only a few cases reported. A few neuroendocrine cells were recognized in the adjacent epithelium of the extrahepatic bile duct, suggesting that the tumor cells might be derived from them. Using immunohistochemical examination, no p53 abnormality was found. Tumor cells showed positive nuclear staining for p16, while negative for cyclin D1, suggesting that functional retinoblastoma protein (pRB) might be lost in the p16/pRB pathway, as in small cell lung cancer.

Clinicopathologic study of mixed adenoneuroendocrine carcinomas of hepatobiliary organs

“…Several cases of hepatobiliary neuroendocrine neoplasms including carcinoid tumors have been reported, but most involve hepatic carcinoids or biliary neuroendocrine neoplasms arising from or accompanying ordinary adenocarcinomas, mostly in patients with gallbladder cancer and extrahepatic CC [10][11][12][13][14]. One case of hepatic NET G1 (carcinoid tumor), but no pure biliary neuroendocrine neoplasms without ordinary CC, has been registered in our laboratories and affiliated hospitals.…”

“…To date, several cases of hepatobiliary neuroendocrine neoplasms, mostly biliary adenocarcinomas accompanying an neuroendocrine component (MANEC), have been reported [10][11][12][13][14], but the neuroendocrine component in biliary MANEC is not well characterized. In this study, we surveyed neuroendocrine neoplasms in hepatobiliary tumors and characterized hepatobiliary MANEC.…”

Small-cell carcinoma of the extrahepatic bile duct: a case report and review of the literature

“…The squamous or glandular components usually lack endocrine differentiation. According to a review of the 16 previously reported cases [1][2][3][4][5][6] and our case of small-cell carcinoma of the extrahepatic bile ducts, elder age, men, a distal site of the extrahepatic bile duct, all tend to be predominant clinicopathological features. Most of the cases showed a poor prognosis, as is the case with the small-cell carcinoma arising in the other organs.…”

“…To our knowledge, only 16 cases of primary small-cell carcinoma of the extrahepatic bile ducts have been previously reported (Table 1) [1][2][3][4][5][6]. Histopathologically, smallcell carcinoma of the extrahepatic bile duct is characterized by a diffuse proliferation of atypical small round cells with hyperchromatic nuclei and scant cytoplasm, which are also characteristics shared by small-cell lung or gastrointestinal carcinoma [7].…”

“…Histopathologically, smallcell carcinoma of the extrahepatic bile duct is characterized by a diffuse proliferation of atypical small round cells with hyperchromatic nuclei and scant cytoplasm, which are also characteristics shared by small-cell lung or gastrointestinal carcinoma [7]. While the carcinomas in more than half of the above reported cases were associated with well-tomoderately differentiated squamous or glandular components, seven cases, including our case, showed carcinomas without any squamous or glandular components [1][2][3][4][5][6].…”