Endocrine Abstracts

Introduction: Medullary thyroid cancer (MTC) accounts for 5-10% of thyroid cancers.25% of cases may be hereditary related to multiple endocrine neoplasia type 2 A (MEN2A) and associated with pheochromocytoma. Metastases from CMT are preferentially lymph node chains. However, other localizations are possible such as adrenal metastases which remain exceptional.

Observation: We report the case of a 35-year-old patient with CMT for which he underwent thyroidectomy and lymph node dissection classified as PT2N0Mx. A search for an associated pheochromocytoma and primary hyperparathyroidism in the context of MEN2A, metoxylate assay and a phosphocalcic assessment were normal. A thoracic-abdominal-pelvic CT scan showed a right adrenal nodule measuring 18x25 mm with a spontaneous density of 31 HU, an absolute washout of 25% and a relative washout of 16% in favour of malignancy. No other secondary locations were found. In order to assess the secretory or non-secretory nature of the nodule, the biological tests for hypersecretion of glucocorticoids, catecholamines and mineralocorticoids were normal. A MIBG scan was performed, showing a right adrenal neuroectodermal process. The patient underwent surgery and the pathological study came back in favour of a non-secreting pheochromocytoma.

Discussion: Two diagnostic hypotheses presented themselves:

- Non-functional pheochromocytoma which can be observed in 14-55% of cases. Although in the case of MEN2A, the pheochromocytoma is most often bilateral.

- The second is a metastasis of medullary thyroid carcinoma, which remains exceptional.