Category: Pituitary Disorders/Neuroendocrinology
Somatostatinoma is a rare neuroendocrine tumor,associated with other endocrine pathologies in syndromic diseases. We present an interesting case of a duodenal somatostatinoma and primary hyperparathyroidism.
Methods : .
A 62 year old f with a history of GERD,well-controlled DM2,and renal calculi presented with a 6-month history of reflux and anemia. Evaluation with EGD was notable for a 2.5 cm submucosal duodenal mass,protruding from the area of the papilla. Initial pathology showed benign cells. Over 2 years, she had serial EGD and EUS at 6 month intervals with repeat pathology. Her abdominal symptoms persisted without improvement despite treatment with PPI. After numerous benign pathological samples,a biopsy near the ampulla was positive for a well- differentiated neuroendocrine tumor; staining positive for Chromogranin,Somatostatin,Synaptophysin,CD56,and Pankeratin;the Ki67 proliferation index was less than 3% consistent with low grade somatostatinoma. An Octreotide scan was negative. Pre-operative CT scan demonstrated a 2 cm mass that was inseparable from the duodenal wall and the pancreatic head. Whipple’s resection was performed and surgical pathology demonstrated a 2.5 x 2.5 x 2 cm mass with necrosis located in the duodenum extending into the pancreatic head with metastatic involvement in 9 of 28 lymph nodes. During the hospitalization,labs showed PTH mediated hypercalcemia with Calcium 14.3 mg/dL and PTH level of 256 pg/ml;treatment with IV hydration and subcutaneous calcitonin led to resolution of hypercalcemia. Gene sequence analysis for Multiple Endocrine Neoplasia Type 1 was negative for MENIN gene mutation. The patient was discharged with outpatient follow-up.
Discussion : A somatostatinoma is a rare neuroendocrine tumor typically located within the pancreas or gastrointestinal tract,commonly the duodenum. Somatostatinomas are characterized by excessive secretion of somatostatin by neuroendocrine cells of Delta cell origin.These tumors can present with Somatostatinoma syndrome characterized by DM, diarrhea, hypochlorhydria,weight loss, and gallbladder disease;however abdominal pain is the most common initial symptom. Somatostatinomas may be part of syndromic diseases such as MEN1,Neurofibromatosis, Tuberous Sclerosis,Von-Hippel Lindau,and Hypoxia-Inducible Factor 2. Surgical resection is the perferred treatment. Medical therapy with somatostatin analogues is used for metastatic disease or inoperable tumors
Conclusion : This is the first reported case in the literature of a somatostatinoma occuring with primary hyperparathyroidism. Although somatostatinomas can be associated with other endocrine diseases as part of a syndrome, there was not a clear link in our patient.
Linden, New Jersey
Graduating endocrinology fellow
Assistant Professor of Medicine
Rutgers New Jersey Medical School
Newark, New Jersey
M.D. Degree: Rutgers-New Jersey Medical School; Residency: Internal Medicine, Rutgers-Robert Wood Johnson Medical School; Fellowship: Endocrinology, Diabetes and Metabolism, Rutgers-Robert Wood Johnson Medical School