Simultaneous Coexistence of Thyrotropin-Prolactin-Secreting Adenoma and Papillary Thyroid Carcinoma

BACKGROUND: The thyrotropin-secreting adenomas are very rare and even more rare when they simultaneously coexist with thyroid carcinoma. So far, only sixteen cases have been reported in the literature. Here, we present a unique case of successful management of a concurrent case of thyrotropin-prolactinoma with papillary thyroid carcinoma. Case Presentation. A 50-year-old Moroccan woman underwent a total thyroidectomy and complementary totalization by iratherapy for papillary thyroid carcinoma, who presented persistence of an inappropriate secretion of the thyroid-stimulating hormone (TSH > 4 mUI/L) despite of levothyroxine suppressive therapy (300 μg/d). After eliminating noncompliance, interfering medicines, and thyroid malabsorption, a pituitary adenoma (12 mm) was documented at magnetic resonance imaging. The patient has had transsphenoidal pituitary adenomectomy with histology confirming a thyrotropin-prolactin-secreting adenoma. After surgery and lanreotide treatment failures, we noted a complete response (TSH < 0.5) with cabergoline treatment (3 mg/week). CONCLUSION: The unusual association of thyroid adenocarcinoma and TSHoma enriches the hypothesis of a potential link between thyrotropic hypersecretion and thyroid carcinogenesis. Our case also illustrates the difficulty of monitoring thyroid carcinoma in nonremission of a TSHoma.