Endocrine Abstracts

Introduction: Thymic neuroendocrine (NE) tumors associated with multiple endocrine neoplasia type 1 (MEN1) are rare, variably documented in 1–8% cases. They are malignant and aggressive tumors and form a major cause of mortality in MEN1.

We report a case of thymic NE carcinoma developing rapidly after parathyroidectomy in a MEN1 patient.

Case: A 45 years old man was allowed for headaches, the biology showed a hypercalcemia, a hypophosphoraemia and high PTH. The imaging revealed polar parathyroidal adenoma with hypophyseal adenoma with rates of prolactinemia=1768 mU/ml. The abdominal MRI–Pet Scan–DG and the scintigraphy in the ocréotide allowed to bring to light a metabolic activity of the mass of the thymic cavity with a necrotic and atypical aspect without distant metastases, five pancreatic nodules and bilateral adrenal nodules without arguments in favour of a pheochromocytoma. The patient has benefited from the resection of a retro-tracheal parathyroidal adenoma, from a malignant thymoma of type invasive P3 the pericardium and the mediastinal fat completed by a mediastinalradiotherapy and hypophyseal adenomectomy.

The search of MEN 1 showed itself positive.

Conclusion: Thymic NE tumors in MEN1 are commoner in males and smokers and are almost always hormonally inactive and diagnosed incidentally.They are malignant, aggressive tumors and are widely invasive and metastatic at presentation (usually to bone). They are never the presenting feature of MEN1 and almost always occur after hyperparathyroidism, providing an opportunity for prophylaxis for these tumors at the time of parathyroid surgery.

Thymic NE tumors present later, usually 15–20 years after. In contrast, our patient had a rapid presentation of thymic NE carcinoma.

Conclusion: These two case reports illustrate the interest of a fine analysis of the usual clinical and biological data as well as the contribution of the current techniques of biology and imaging for the etiologic and topographic diagnosis of hormonal hypersecretions of which some are as here, very exceptional.