Endocrine Abstracts

Introduction: Primary and metastatic testicular neuroendocrine tumours (por mTNETs) are rare and account for less than 1% of testicular tumours. Testicular mass is the commonest presentation, with radical orchidectomy being treatment of choice. Carcinoid syndrome is rare at 1-3 % of cases. Carcinoid heart disease is even more rare in TNET but notably the right testicular vein drains into inferior vena cava (IVC) and left testicular vein drains into left renal vein then IVC bypassing the liver. We report a rare case of carcinoid heart disease in TNET.

Case report: A 72 year old man, with a background of radical prostatectomy and cystectomy with ileal conduit formation, was found to have a testicular mass. This completely resected with radical orchidectomy with histology revealing a well differentiated NET, Grade 2, Ki 67 of 5 % expressing Chromogranin, CD56 and Synaptophysin. No germ cell (GCNIS) or teratoma were seen. CT and MRI Imaging showed solitary liver metastasis with biopsy confirming metastatic NET but Ki 67 was <2 %. Clinically he had signs of right sided heart failure with CV waves, a systolic murmur consistent with tricuspid regurgitation, pulsatile liver, and lower limbs pitting oedema. His urinary 5-HIAA was 276umol/24 hours (0-37) and Chromogranin A of 3941 ng/mL (0-105). Full staging was performed. Octreoscan SPECT-CT revealed a solitary liver lesion and no other primary. Echocardiogram confirmed a retracted and thickened tricuspid valve leaflets with poor mobility resulting in severe/torrential free flow TR and moderate PR with RV dilatation with good RV function with mild LVSD. Carcinoid syndromic features had improved since orchidectomy. Lanreotide Autogel 120 mg deep sc every 28 days was commenced, with significant improvement with no flushing or diarrhoea after 3 injections. Clinically RHF improved. He declined any further major surgeries.

Conclusion : TNETs are very rare form of NETs whether primary or secondary. Due to their venous drainage into IVC, carcinoid syndrome can develop as well as carcinoid heart disease. Given the rarity of pTNET full work up of the small bowel is underway to ensure there is not a primary or concomitant small bowel lesion.