Primary hepatic leiomyosarcoma masquerading as focal nodular hyperplasia of liver: A wolf in sheep's clothing.

Primary hepatic leiomyosarcoma is a rare hepatic malignancy which requires exclusion of other primary site of origin. Clinical presentation and imaging of this tumor is nonspecific and mimics many other hepatic neoplasms. A 62-year-old female patient presents here with right hepatic mass with insidious onset and radiological features favoring a benign solid lesion suggestive of focal nodular hyperplasia. On right hepatectomy, an encapsulated mass identified about 11 cm in maximum dimension with pushing margin and central scar-like area. Histopathological examination reveals a spindle cell tumor and panel of immunohistochemical markers is required to distinguish it from other morphological mimickers. Diagnosis of primary hepatic leiomyosarcoma requires histopathology along with immunohistochemical examination. It is thus advisable to do preoperative biopsy with immunohistochemistry in all patients having atypical imaging and clinical features.