Primary Leiomyosarcoma of Liver Mimicking Liver Abscess in a 40 Year Female
A 40-year-old female came with complaints of pain in right hypochondrium. She had no history of liver disease or alcohol abuse. Liver function tests were mildly elevated and all tumor markers were normal. USG abdomen was suggestive of hepatomegaly with large thick walled cystic lesion showing thick internal septations? Liver abscess PET-CT revealed intensely FDG avid large well circumscribed heterogeneous lesion in segment IV, VIII of liver extending to segment V, showing necrosis and large enhancing solid component and few enhancing septations within a non-enhancing area, highly suspicious for neoplastic etiology. No scan evidence of abnormal hypermetabolism elsewhere in the body. A liver biopsy of the lesion was done and a diagnosis of spindle cell tumor with nuclear atypia was given, which is followed by extended right hepatectomy resection. Macroscopically, there was a breach in the capsule, and the liver had been replaced by a tumor with a maximum diameter of 16 cm with necrotic and hemorrhagic areas. In microscopic findings, the tumor consisted of the proliferation of spindle cells arranged in fascicles and storiform patterns with large areas of necrosis and hemorrhage. Moderate nuclear atypia was observed with increased mitosis (>19/10 HPF) making it FNCLCC grade 2 (score 5). Immunohistochemical staining for Smooth Muscle Actin (SMA), Vimentin, and h-caldesmon showed diffuse cytoplasmic positivity in all tumor cells with 45% Ki-67 along with negative staining for C-kit, S100, CD34, CD31, CD117, EMA, PanCk, Hep-par1, L-arginase, HMB45, MDM2 and DOG1, informing a final diagnosis of primary hepatic leiomyosarcoma.
