MON-083 - Ovarian Carcinoid Tumor Causing Carcinoid Syndrome and Carcinoid Heart Disease in A Patient with ESRD

Background: Primary ovarian carcinoid tumors are rare neuroendocrine neoplasms, representing less than 0.1% of ovarian tumors and approximately 1% of all carcinoid tumors. Although uncommon, up to 30% of affected patients develop carcinoid syndrome, and nearly one-quarter of these patients progress to carcinoid heart disease. Unlike gastrointestinal carcinoid tumors, ovarian carcinoids can cause systemic hormonal manifestations in the absence of hepatic metastases due to direct venous drainage into the systemic circulation.

Case: A 31-year-old woman with end-stage renal disease (ESRD) on hemodialysis presented with chronic diarrhea, nausea, and newly identified severe tricuspid and pulmonary valve regurgitation. Transthoracic echocardiography demonstrated thickened, immobile right-sided valve leaflets, raising concern for carcinoid heart disease. Biochemical evaluation revealed chromogranin A of 406 ng/mL (NORMAL RANGE) and plasma 5-hydroxyindoleacetic acid (5-HIAA) of 3,287 ng/mL (reference < 30 ng/mL). Measurement of 24 hour urinary 5-HIAA was not feasible due to anuria, making plasma 5-HIAA critical for diagnosis.

MRI and CT abdomen and pelvis identified a large pelvic mass measuring 17 x12 x 9 cm initially presumed to be an extrauterine fibroid. Ga-68 DOTATATE PET/CT demonstrated intense somatostatin receptor uptake confined to the pelvic mass without evidence of metastatic disease, supporting the diagnosis of a functional pelvic neuroendocrine tumor. Long-acting octreotide therapy was initiated for hormonal control prior to surgery.

Given her advanced carcinoid heart disease, the patient first underwent tricuspid and pulmonary valve replacement, with pathology confirming serotonin-mediated fibrotic valvulopathy. Definitive surgical management with exploratory laparotomy and right salpingo-oophorectomy revealed a 17-cm ovarian mass. Histopathology demonstrated an insular-type ovarian carcinoid tumor confined to the ovary (FIGO stage IA). Postoperatively, carcinoid symptoms resolved completely.

Conclusion: This case highlights the utility of plasma 5-HIAA as an alternative to urinary 5-HIAA for making the diagnosis of carcinoid syndrome in patients with ESRD. Additionally, Ga-68 DOTATATE PET/CT is a valuable imaging modality in this patient population for tumor localization and differentiation of carcinoid tumors from benign appearing masses on conventional imaging. Early endocrine recognition and coordinated multidisciplinary management can lead to curative outcomes in patients with rare functional ovarian carcinoid tumors.

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