A rare case of perivascular epithelioid cell tumor (PEComa) of the pancreas diagnosed by endoscopic ultrasound

Abstract

A 49-year-old woman consulted her general practitioner (GP) regarding epigastric pain that she had experienced for 2 months. Physical examination and laboratory results were unremarkable. An abdominal ultrasound indicated a solid pancreatic tumor, which was confirmed on subsequent CT and MRI. Endoscopic ultrasound (EUS) showed a well-defined heterogeneous, predominantly hypoechoic mass in the pancreatic body, so a neuroendocrine tumor (NET) was suspected. However, EUS-guided fine-needle aspiration (EUS-FNA) was performed and based on (immuno-)histochemical findings, the extremely rare diagnosis of a perivascular epithelioid cell tumor (PEComa) of the pancreas was made. Due to the malignant potential of pancreatic PEComas, laparoscopic left-sided pancreatectomy was performed. We present a case diagnosed by preoperative EUS-FNA highlighting the clinical and endosonographic features which help to distinguish it from its most important differential diagnosis, neuroendocrine tumors (NETs) of the pancreas.

Neuroendocrine pancreatic tumor in a patient with dual diagnosis of tuberous sclerosis complex and basement membrane disease: A case report and review of the literature

“…In our case, the main differential for a pancreatic lesion with such imaging characteristic is pancreatic perivascular epithelioid cell tumor (PEComa) which is reported to appear very similar to pancreatic neuroendocrine tumors on imaging (well-circumscribed, oval or round-shaped not hypovascular mass) [26] . Moreover, mutations of the TSC2 gene are usually found in sporadic PEComas.…”

Comments on and Illustrations of the EFSUMB CEUS Guidelines: Transabdominal and Endoscopic Ultrasound Features of Intrapancreatic Metastases and the Role of Multiparametric Imaging and EUS-Guided Sampling in Rare Pancreatic Tumors

“…The only exception is the intrapancreatic accessory spleen with long lasting enhancement in CEUS and CH-EUS [84,85]. The very rare PEComa has also been described on CH-EUS with marked and prolonged hyperperfusion, with a washout of the lesion at a late stage [82]. The description of a hyperenhancement of RCC metastases in the venous phase of CEUS contrasts with the results of Fusaroli et al in CH-EUS.…”

“…In the study by Kitano et al, a hypoenhanced pancreatic lesion corresponded to PDAC, with a sensitivity and specificity of 95% and 98%, respectively [69,78]. In contrast, good vascularization with hyperenhancement has been described for most neuroendocrine tumors [79,80], RCC metastases, intrapancreatic accessory spleens [81], and the extremely rare PEComa (perivascular epithelioid cell tumor) [82]. Focal inflammatory lesions may be hyperenhanced or isoenhanced.…”