Endoscopic ultrasound-guided fine-needle aspiration diagnosis of clear-cell pancreatic endocrine neoplasm in a patient with von Hippel-Lindau disease: a case report

Unveiling lipid-rich ("clear cell") pancreatic neuroendocrine tumor: A small series of two cases with literature review

This study presents two cases of lipid-rich pancreatic neuroendocrine tumors (PanNETs), a rare variant posing significant diagnostic challenges in fine needle aspiration (FNA) cytology and small biopsies. The first case involves an elderly male with a pancreatic tumor, displaying distinct cytoplasmic vacuoles, while the second case is a middle-aged male present with a pancreatic tail mass exhibiting foamy cytoplasm and eccentric nuclei, infiltrating in the stroma. Both cases did not exhibit typical morphologic features of PanNET but demonstrated cytomorphologic features and infiltrative growth patterns that mimicked adenocarcinoma. Further work-up demonstrated that both tumors were immunoreactive for synaptophysin and chromogranin, and were interpreted as well-differentiated, PanNET, lipid-rich variant. The study highlights the overlapping morphological features between lipid-rich PanNETs and other pancreatic neoplasms and underscores the importance of comprehensive cytological and immunohistochemical analysis for accurately diagnosing this variant, particularly due to the risk of misinterpreting it as pancreatic adenocarcinoma. Recognizing lipid-rich PanNETs is crucial for appropriate clinical management, as their identification can significantly impact treatment decisions and patient outcomes.

Synchronous pancreatic tumors in a patient with history of Wilms tumor: A case of pancreatic adenocarcinoma and lipid-rich neuroendocrine tumor diagnosed by cytopathology

Synchronous tumors represent a very small portion of pancreatic tumors. Although there is a higher incidence of secondary malignant neoplasms (SMN) in patients with history of Wilms tumor (WT), pancreatic tumors are very infrequent SMNs in this population. We report the first case of synchronous pancreatic tumors in a patient with history of WT. Two separated pancreatic lesions were identified by abdominal computerized tomography (CT) scan. Fine-needle aspiration of both lesions was performed for cytopathology examination. A pancreatic adenocarcinoma was diagnosed in the head of pancreas, and the pancreatic body lesion was found to be a neuroendocrine tumor (NET). The NET had characteristic vacuolated lipid-rich cytoplasm. Further molecular testing was done on both tumors, but no common cancer-associated mutation was found.

Two unusual variants of pancreatic neuroendocrine tumor and their potential pitfalls on fine-needle aspiration cytology

Endoscopic ultrasound-guided fine-needle aspiration is increasingly utilized for the diagnosis of pancreatic lesions. Although operator dependent, the procedure has good overall performance characteristics and is minimally invasive; however, accuracy and sensitivity are reportedly lower for pancreatic neuroendocrine tumor (PanNET) compared with the more common pancreatic ductal adenocarcinoma (pACA). The underperformance is further exacerbated by the unusual cases of PanNET presenting with variant cytomorphology. We report two separate diagnostically challenging cases: a pigmented PanNET and a clear cell PanNET. We briefly review the literature and emphasize the importance of recognizing these uncommon variants when encountered in aspirate material. Diagn. Cytopathol. 2017;45:371-378. © 2016 Wiley Periodicals, Inc.

Clear cell neuroendocrine tumor of pancreas: Endoscopic Ultrasound-guided fine needle aspiration diagnosis of an uncommon variant

The cytomorphologic features of clear cell neuroendocrine tumor of pancreas have been rarely reported in cytology literature. The cytomorphology of this rare variant mimics many primary and metastatic clear cell tumors of the pancreas. However, a precise cytological diagnosis can be rendered by awareness of this entity and judicious use of immunohistochemistry. We report one such case in a young woman diagnosed on endoscopic ultrasound fine needle aspiration. The tumor cells showed positive staining with synaptophysin, chromogranin, and also with inhibin.

Cytologic features of pancreatic adenocarcinoma with "vacuolated cell pattern." report of a case diagnosed by endoscopic ultrasound-guided fine-needle aspiration

The "vacuolated cell pattern" has only been recently described as a distinct morphologic variant of pancreatobiliary adenocarcinoma. Herein, we report the endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) cytologic features of a case of pancreatic adenocarcinoma with "vacuolated cell pattern" occurring in a 60-year-old man. The aspirate smears and cell block sections from the EUS-FNA of a 23.5 mm hypoechoic pancreatic head mass were highly cellular, showing variably-sized crowded three-dimensional cell clusters, flat sheets, and numerous highly atypical single cells. The background was bloody and showed necrotic debris, but no discernible mucus. The most striking feature of the aspirate was the presence of numerous very large (20-50 µm) vacuoles, occupying the entire cytoplasm, pushing the nuclei to the side and indenting them, that imparted a cribriform appearance to the sheets of neoplastic cells. The non-vacuolated neoplastic cells were large, had abundant dense (squamoid) cytoplasm, irregularly contoured hyperchromatic nuclei, and prominent macronucleoli. Histologic evaluation of the pancreatectomy specimen showed a "vacuolated cell pattern" adenocarcinoma composed of poorly formed glands, solid sheets, and infiltrating single cells with pleomorphic nuclei and large cytoplasmic vacuoles. To our knowledge, this is the first report describing the cytologic features of this rather uncommon morphologic variant of pancreatic adenocarcinoma. Recognition of this morphologic variant of pancreatic adenocarcinoma in ESU-FNA samples allows its differentiation from primary and metastatic signet-ring cell carcinomas.

Multiple endocrine neoplasms and serous cysts of the pancreas in a patient with von Hippel-Lindau disease

INTRODUCTION

Patients with the von Hippel-Lindau (VHL) syndrome have an increased risk of developing pancreatic endocrine neoplasms.

CASE REPORT

A 40-year-old female with a past history of bilateral adrenal pheochromocytomas, whose brother had a history of a malignant pheochromocytoma, was referred to our institution with symptoms of adrenal crisis including general fatigue and insomnia in spite of increasing predonisolone therapy. Screening by ultrasonogram and computed tomography demonstrated multiple well-demarcated, enhancing nodules (maximum, 3 cm) in the head and tail of pancreas and multiple cystic lesions throughout the entire pancreas. Although this patient met the criteria for VHL, magnetic resonance imaging for her brain did not reveal any lesions. Pancreatoduodenectomy with partial distal pancreatectomy was performed. Histologic examination of the resected pancreas revealed multiple well-differentiated endocrine neoplasms accompanied with multiple serous cysts. The patient remains free of disease 5 years after surgery.

Pancreatic manifestations of von Hippel-Lindau disease

Von Hippel-Lindau disease is an uncommon, multisystem, multitumor disorder that can present in sporadic form but is more commonly inherited as an autosomal-dominant disease with high penetrance. Affected patients are at increased risk for developing multiple synchronous or metachronous benign or malignant, cystic, and vascular neoplasms of various organs. The characteristic neoplasms associated with von Hippel-Lindau are hemangioblastoma of the central nervous system and retina, clear cell renal cell carcinoma, and pheochromocytoma, but other lesions are well recognized. Pancreatic lesions, both primary and metastatic, are common, and several differential diagnostic possibilities must be considered.