Carcinosarcoma (adenocarcinoma, neuroendocrine carcinoma, undifferentiated carcinoma and chondrosarcoma) of the gallbladder.

We present an extremely rare case of carcinosarcoma with 4 different tumor components in an 88-year-old female. After a diagnosis of acute cholecystitis, we performed percutaneous transhepatic gallbladder drainage in the patient without success, followed by a cholecystectomy and choledocholithotomy. The mass was a 60 × 25 mm polypoid lesion of the gallbladder identified histologically as a carcinosarcoma with adenocarcinoma, neuroendocrine carcinoma, undifferentiated carcinoma and chondrosarcoma components. The biliary-type adenocarcinoma portion exhibited acinar growth patterns with columnar cells having large and markedly hyperchromatic nuclei. These tumor cells were immunohistochemically positive for MUC1 and CDX2. The neuroendocrine carcinoma, small cell type, cells were densely packed and small, with scant cytoplasm, finely granular nuclear chromatin and absence of nucleoli. The mitotic index was high. These tumor cells were immunohistochemically positive for synaptophysin, Ki-67 (index 40%), MUC1, CDX2 and c-Kit. The undifferentiated carcinoma consisted exclusively of spindle cells containing large, markedly hyperchromatic nuclei with a high mitotic index. These tumor cells were immunohistochemically positive for AE1/AE3. The chondrosarcoma was composed of blue-gray chondroid matrix and atypical chondrocytes containing large, hyperchromatic nuclei. These tumor cells were immunohistochemically positive for S100. Its attributes might be suggestive of a greater malignant potential and pathogenesis of carcinosarcoma.