A CASE REPORT OF VON HIPPELLINDAU DISEASE WITH METASTATIC FOLLICULAR THYROID CARCINOMA AND RECURRENT PHEOCHROMOCYTOMA

ASSOCIATION OR COINCIDENCE?

Abstract

INTRODUCTION
Von Hippel-Lindau (VHL) disease is a rare autosomal dominant syndrome caused by germ line mutations in the VHL tumor suppressor gene. VHL manifestations encompass a spectrum of tumors, namely retinal and central nervous system hemangioblastomas, renal cell carcinoma, pheochromocytoma, pancreatic endocrine tumours and endolymphatic sac tumours. However, the association between VHL and follicular thyroid carcinoma (FTC) is unknown.

CASE
A 25-year-old lady with unremarkable family history was diagnosed with metastatic FTC and pheochromocytoma 10 years ago. She underwent a right adrenalectomy and was in remission postoperatively confirmed by normal 24-hour urinary catecholamines. As for the FTC, she underwent total thyroidectomy and 2 sessions of radioactive iodine ablation therapy for lymphovascular invasion and bone metastases. Post-ablation whole body scans and thyroglobulin level were normal. Unfortunately, she was lost to follow-up and presented 5 years later with headache, palpitation and uncontrolled hypertension. 24-hour urinary catecholamines revealed elevated noradrenaline and CT scan showed a left adrenal mass, suggestive of a recurrent pheochromocytoma and was treated with left adrenalectomy. Molecular genetic testing demonstrated c.467A>G (p.Tyr156Cys), which is confirmatory of VHL disease.

CONCLUSION
This is the first reported case of bilateral pheochromocytoma and FTC in VHL disease. The association of VHL gene alteration and thyroid carcinoma particularly FTC from literature is scarce. More studies are needed to evaluate the association between VHL and FTC to determine the surveillance strategy, prognosis and appropriate treatment.