Hepatic Inflammatory Myofibroblastic Tumors Presenting with Recurrent Abdominal Pain

Abstract

Purpose: Inflammatory myofibroblastic tumors (IMTs) are infrequent solid neoplastic mesenchymal proliferations composed of myofibroblastic spindle cells with inflammatory infiltrates with aberrant expression of anaplastic lymphoma kinase (ALK). IMT has a propensity for pulmonary and gastrointestinal tract while other rare locations have been documented. The etiology and pathogenesis of IMT remains unclear, although it was initially thought to represent a reactive process. Factors that have been hypothesized in the pathogenesis include infection, vascular diseases, and autoimmune disorders. We describe a 33-year-old African American female with history of lupus and end-stage renal disease on hemodialysis who presented to the hospital with recurrent abdominal pain. A 0.8 cm hepatic lesion at the dome of the liver was identified 8 months prior, suspected to be a hemangioma. Other etiologies of abdominal pain were entertained as it was least likely to be the culprit. Two months after her initial episode, she re-presented to the hospital with another bout of severe abdominal pain but this time it was localized to the right upper quadrant with associated fevers. She underwent abdominal ultrasound which disclosed a new 2.4 x 2.1 cm lesion in the posterior right hepatic lobe. The previously noted 0.8 cm lesion on the hepatic dome remained unchanged. Though initially thought to be an abscess, it lacked the typical appearance on high resolution imaging. Due to persistent fevers, she underwent CT guided aspiration and biopsy of the lesion. Cultures of the aspirate were unrevealing and the fevers were attributed to line infection. Biopsy showed a fibro-inflammatory process without any specific etiology. She was treated with intravenous antibiotics for line sepsis and had complete resolution of her symptoms only to present 6 months later with recurrent abdominal pain. Unfortunately, a repeat CT of the abdomen showed an increase in the size of the known lesion, now measuring 3.5x3.5 cm. She underwent another CT guided core biopsy of the hepatic lesion which revealed an ALK positive inflammatory myofibroblastic tumor. Due to her debilitating symptoms, she was referred for partial resection, and is currently awaiting surgery. Herein, we describe a case of an aggressively growing ALK positive inflammatory myofibroblastic hepatic tumor. Though multiple factors such as infections, vascular, and autoimmune diseases have been hypothesized in the pathogenesis of IMT, the etiology in our patient remains elusive.