A Rare Intruder of the Liver: A Case of Undifferentiated Pleomorphic Sarcoma.

Undifferentiated pleomorphic sarcoma (UDS) is a rare and aggressive form of cancer that poses significant diagnostic and therapeutic challenges. The most common sites of this malignancy include the extremities. It is less common in visceral organs and the liver has rarely been reported as a primary site of disease. This subset of cancer is characterized by anaplastic and highly heterogeneous cells that lack specific markers of differentiation, making it difficult to identify and treat effectively. Due to vague symptoms that mirror other pathologies of the affected organ(s), UDS can present like various sarcomas or metastatic processes. A thorough microscopic analysis with the use of ancillary testing including immunohistochemistry can aid in the identification of UDS, as clinical symptoms can be non-specific. It is important to characterize primary malignant lesions since treatment options can range from medical therapy to surgical intervention. We present a unique case of UDS of the liver in a patient with obstructive jaundice.