Solitary Fibrous Tumor of the Liver: Case Report

Abstract

Introduction: Solitary fibrous tumor (SFT) of the liver is a rare mesenchymal tumor. Most patients are asymptomatic. Clinic-radiological features are non-specific. Definitive diagnosis of SFT is usually made based on the histological features and immunohistochemistry data of the resected specimen. In this case report, we describe the case of an elderly female who presented with a large mass in the left lobe of the liver with normal level of tumor markers and atypical radiological findings. The patient successfully underwent resection of the tumor and the diagnosis was confirmed on histopathology. Methods: A 81-year old woman with abdominal pain for the past 2 months. Examination revealed a large mass palpable in the epigastric region. CT and MRI showed a 25×16 cm-sized hypervascular mass arising from the left lobe of liver. The mass displace stomach, the transverse colon and cause a chronic obstructive pancreatitis due to the compression. The level of tumor markers was within the normal limits: AFP 3.3 ng/ml, CEA 2.3 ng/ml, and CA 19-9−27 U/ml. Liver functions were in the normal range. Based on the atypical imaging findings biopsy of the lesion was done. It was suggestive of solitary fibrous tumor. Since the lesion was resectable, surgery was planned. Trans-arterial chemoembolization was done before the surgery without incidences. The patient underwent left lateral sectionectomy. Intraoperatively, a solitary large tumor arising from the segment II and III of the liver was identified and no evidence of distant metastasis. The postoperative course was uneventful. The tumor measured 19 ×14 x9,5 cm-sized, with an external well delimited surface. Microscopic examination showed atypia with spindle cells and collagen bundles between the tumor cells. On IHC, the tumor was positive for STAT6, CD34, Bcl2, and focal and patched positive for CD34 y CD99. There was no evidence of recurrence on follow-up for 7 months. Conclusion: SFT of the liver is a rare entity. Most patients are asymptomatic, but in some cases, abdominal fullness and palpable masses are present. Definitive diagnosis is made based on the histological features and immunohistochemistry data of the resected specimen. IHC remains the most important tool for conclusive diagnosis of SFT. Complete surgical excision is the treatment for hepatic SFT. Follow up is advised as some of the patients with benign tumors on initial histological examination developed distant metastasis later.