Perivascular epithelioid cell tumor of pancreas on the background of chronic liver disease: a case report and review of literature

Abstract

Perivascular epithelioid cell tumours, known as PEComas, of the pancreas are an extremely rare group of neoplasms. This heterogenous entity includes angiomyo­lipo­ma (AML), clear cell sugar tumour (CCST), lymphangioleio­myoma (LAM), and another group of lesions originating from the soft tissues and organs with similar histological and immunophenotype characteristics. To date, only 23 cases have been reported throughout the world with different clinical presentations. We report a 52-year-old lady who presented with a symptomatic mass in the body of the pancreas on the background of hepatitis B virus (HBV)-related chronic liver disease (CLD). She presented with abdominal pain of 2 months' duration. On initial computed tomography (CT) imaging, it revealed a homogenously enhancing lesion in the body of the pancreas. It was T2 isointense on magnetic resonance imaging (MRI), and there was no uptake present in the 68Ga DOTONAC scan. Endoscopic ultrasound with fine needle aspiration (FNA) showed paucicellular material with occasional dysplastic cells. On account of suspicion of a non-functional neuroendocrine tumour, she underwent a distal pancreatosplenectomy. Intra-operatively, the lesion was encapsulated and hard in consistency, and the rest of the pancreas was soft with an undilated MPD. She had a smooth postoperative recovery. Final histopathology revealed benign PEComa of the distal body and tail of the pancreas with HMB 45 and SMA positivity on IHC. Currently, she has been on regular follow up for the last 12 months. PEComas usually present as a histological surprise and are a diagnosis of exclusion. However, knowledge of this exceptionally rare tumour makes diagnosis at the pre-operative level more certain. Resection must be considered, as it leads to a good prognosis and survival.