Unveiling a Rare Pathology: Case Report of Carcinosarcoma of the Gallbladder

Gallbladder carcinosarcoma (GBCS) is a rare and aggressive biliary tract malignancy, constituting approximately 1.7% of gallbladder cancers, with fewer than 100 cases reported in the English literature as of 2023. These tumors, often affecting gynecological organs, feature both carcinomatous and sarcomatous components. They predominantly occur in females, with a mean presentation age of 66 years. Diagnosis is primarily based on pathological analysis, and the mainstay of treatment is surgical excision.

We present a case of an 81-year-old female with no significant medical history, who was admitted after a fall. A CT scan revealed an 18.2 cm gallbladder mass extending into the liver and colon. The patient underwent tumor resection. Pathological examination confirmed a carcinosarcoma with osteoid and cartilage elements, supported by immunohistochemical staining as gallbladder primary.

Carcinosarcomas are composed of both epithelial (commonly adenocarcinoma) and mesenchymal (spindle cell) components. Their pathogenesis remains poorly understood. Typically diagnosed at advanced stages, these tumors have a poor prognosis, with survival rates ranging from 2.9 to 6 months. Gallbladder carcinosarcomas behave similarly to sarcomas, exhibiting rapid growth and resistance to both radiation and chemotherapy. Current treatment consensus involves surgical excision of the gallbladder, extrahepatic bile duct, regional lymphadenectomy, and possibly pancreaticoduodenectomy depending on tumor extent.

Gallbladder carcinosarcoma is a rare and aggressive malignancy with a poor prognosis even following complete resection. Given the limited number of cases, further research is necessary to improve treatment strategies for these patients.