Abstract
Casestudy: Pancreatic neuroendocrine neoplasms (PanNEN) are rare accounting for 2-5% of pancreatic tumors. Although mostly sporadic, 10-20% are associated with inherited syndromes, notably MEN-1, Von Hippel- Lindau disease, neurofibromatosis type 1, and tuberous sclerosis (TS). When compared to sporadic cases, PanNEN in hereditary syndromes occur at a younger age, are often multifocal, cystic, and may show characteristic microscopic patterns. TS is an autosomal dominant multi-system disorder with mutations involving TSC1 or TSC2 genes which function as tumor suppressors by inhibiting mTORC1 kinase. PanNEN is observed in 1.5-1.8% of patients with TS and no surveillance guidelines for the assessment of pancreatic lesions are established. Compared to other syndromes, PanNEN associated with TS are solitary. To our knowledge, only two cases of multifocal PanNEN in TS patients have been reported. We present a case of a 67-year-old gentleman with a history of TS also affecting two daughters. He presented to the emergency department with severe abdominal pain. Abdominal ultrasound suggested acute appendicitis and an incidental 2.0 cm solid lesion was noted in the head of the pancreas. Follow-up MRI revealed two additional non-cystic masses in the pancreatic tail. Endoscopic ultrasound-guided biopsy of a tail lesion revealed monomorphic tumor cells with stippled chromatin without cytologic atypia. Immunohistochemical staining was positive for synaptophysin and chromogranin. Ki-67 labelling index was under 1%. Diagnosis of a well-differentiated neuroendocrine tumor (G1) was made. The patient denied symptoms of the carcinoid syndrome and no biologically active hormones were detected. Gallium PET scan revealed multiple foci of radiotracer uptake throughout the pancreas in addition to those described on MRI. Although PanNEN are rare in TS, malignant behavior has been reported. This case reinforces the importance of early detection through active surveillance, especially as surgical options may be limited in multifocal disease.
Diagnostic and Interventional Role of Endoscopic Ultrasonography for the Management of Pancreatic Neuroendocrine Neoplasms
