Mesenchymal Tumors of the Liver

Abstract

Purpose: Solitary fibrous tumors (SFT) are neoplasms of ubiquitous distribution. Most commonly they arise from serosal surfaces. Primary SFT arising within the liver parenchyma are extremely rare and the descriptions are limited to isolated case reports. We report a case of 76 yr-old female with SFT of the liver. The patient has a history of breast cancer and underwent lumpectomy with sentinel node and axillary node dissection five years ago. She was presented to the oncologist office with history of marked weight loss. Her follow-up PET scan found increased uptake in the ascending colon. Colonoscopy revealed a 32 mm sessile polyp in the distal part of ascending colon. Histology revealed villous adenoma with focal high grade dysplasia/adenocarcinoma in situ. She underwent laproscopic right hemicolectomy with anastomosis of the terminal ileum to transverse colon. The two year follow-up in the physician's office was noteworthy for nonspecific intermittent abdominal pain and weight loss. PET scan revealed a 6 cm solid mass in the right lobe of the liver. Ultrasound guided FNAC of hepatic lesion was distinctive of spindle cell tumor. No significant pleomorphism, hemorrhage, nor necrosis seen. Immunostains were positive for CD34 and Bcl-2. Desmin and c-Kit mutation analysis were negative. In the absence of any other known extra hepatic tumor locus as evidenced by PET imaging, SFT of liver was diagnosed. Patient was advised to undergo surgical resection of the tumor. However she decided to seek second opinion regarding the surgery and prognosis. Less than twenty five cases of primary hepatic SFT are reported in literature. More common in females (F: M ratio 7:3). Most common symptoms are abdominal discomfort/pain/mass, weight loss, fatigue, and elevated liver functions and, hypoglycemia. The proposed mechanism for the tumor induced hypoglycemia is the production of a high molecular weight protein with non-suppressible insulin like activity. SFT of liver commonly involve the right lobe than the left. Radiologically they appear well demarcated hypo or hyperechogenic masses. Histologically, SFT have spindle cell pattern composed of collagen. They are immunologically positive for vimentin, CD34 and negative for desmin. Large seize, necrosis, high mitotic rate, cellular pleomorphism and atypia, are associated but not predictive of aggressive nature. Due to their rapid growth, the outcome depends mainly on resectability than metastases, which are rarely reported. Due to the limited cases in literature and its varied presentation, it is difficult to establish a long-term prognosis. The absence of metastatic disease at the time of resection and over the ensuing 10 months is encouraging.