Background: Primary hepatic carcinosarcoma is a rare malignant tumor containing an intimate mixture of carcinomatous and sarcomatous elements. Reports on risk factors, epidemiology, and pathogenesis of the tumor as well as the experience in its treatment are limited.
Method: We present a case of primary carcinosarcoma of the liver in a 69-year-old man who complained of right hypochondrial pain and weight loss for two months.
Results: Magnetic resonance imaging revealed a 14 x 12 cm mass in segments 7-8 and 4 of the liver with vena hepatica invasion. An ultrasonography-guided biopsy showed osteoid tissue without osteoblastic rimming. Vascular structures accompanied the osteoid tissue. The patient underwent surgery after a diagnosis of hemangioma. Intraoperative frozen sections revealed a carcinosarcoma associated with an osteosarcoma and cholangiocellular carcinoma components.
Conclusions: Preoperative diagnosis of this rare primary hepatic malignant tumor may be difficult by biopsy owing to intratumoral heterogeneity. Highly mature areas of the osteosarcomatous component may lead to misdiagnosis of metaplastic bone tissue. Clinicopathologic features of this rare entity are discussed.