Endocrine Abstracts

Background: Primary ovarian neuroendocrine tumours (NETs) are rare and may secrete serotonin, causing carcinoid syndrome and occasionally carcinoid heart disease (CHD) through direct release of vasoactive peptides. The NETTER-1 trial showed that ^177Lu-Dotatate (PRRT) significantly improves progression-free survival in progressive advanced midgut NETs on somatostatin analogues and is NICE-recommended. Evidence for PRRT in metastatic ovarian NETs with SSTR expression is lacking, though data from large CUP-NET cohorts demonstrate clinical efficacy. A multidisciplinary and personalised approach remains essential.

Case Summary: A 58-year-old woman with type 2 diabetes and asthma presented with presumed postmenopausal symptoms and bleeding. Ultrasound revealed a 13 cm pelvic mass (2021). Preoperative echocardiography for planned hysterectomy unexpectedly showed carcinoid heart disease with thickened, retracted tricuspid valve leaflets and moderate pulmonary regurgitation. She reported long-standing flushing, diarrhoea, fatigue, and pedal oedema. Urinary 5-HIAA (536 µmol/24 h) and chromogranin A (1275 pmol/l) were markedly elevated, confirming carcinoid syndrome. She underwent uneventful tricuspid and pulmonary valve replacement with coronary bypass (2022), followed by pelvic mass resection (2023). Histology confirmed an insular-type ovarian carcinoid (Grade 1, Ki-67 <1%). After 12 months of stability, follow-up ^68Ga-DOTATATE PET-CT (2024) demonstrated hepatic and pulmonary metastases (Krenning 4) with normal markers (5-HIAA 20 µmol/24 h), complicating surveillance. Following NET MDT review, she received compassionate PRRT, which was well tolerated, and follow-up continues.

Discussion and Conclusion: Ovarian NETs are rare. PRRT use in metastatic ovarian NETs is based on limited case reports and extrapolated data but is supported by ESMO 2024 and ENETS guidelines. Early recognition, somatostatin receptor imaging, and multidisciplinary coordination are vital to optimise outcomes. This case illustrates overlapping menopausal and carcinoid symptoms, with carcinoid heart disease diagnosed incidentally. Achieving both tumour and hormonal control is crucial. Compassionate PRRT proved beneficial, underscoring the need for global collaboration to strengthen evidence and ensure access to functional imaging for accurate assessment and follow-up.