Abstract

Background A 45-year-old man presented with frontal headache and visual disturbances to our clinic. For the previous 5 years, he had been receiving treatment for long-lasting mild hyperthyroidism with antithyroid therapy, but therapy had not been carefully followed. During the last 2 years he had also complained of erectile dysfunction and loss of libido. On physical examination, he had a small goiter, normal skin, no Graves' ophthalmopathy, normal BMI, and reduced testis volume and pubic hair.

Investigations Serum levels of free T₃ and T₄, serum prolactin, testosterone, serum gonadotropins, insulin-like growth factor 1, adrenocorticotropic hormone, and cortisol were measured. MRI scan, TSH-releasing hormone test, and T₃ suppression test were carried out. Levels of pituitary glycoprotein hormone -subunit and sex-hormone-binding protein were also measured.

Diagnosis Hyperthyroidism caused by a mixed pituitary adenoma that secretes prolactin and TSH.

Management Trans-sphenoidal resection of the pituitary tumor. After surgery, T₃ suppression test failed to completely suppress TSH secretion, which suggested a persistence of residual adenomatous cells. Hyperthyroidism and hypogonadism recurred after 5 years, therefore, treatment with lanreotide was initiated, and resulted in complete resolution of signs and symptoms of the disease.

Author affiliations

1. P Beck-Peccoz is Professor of Endocrinology in the Department of Medical Sciences, University of Milan and Director of the Endocrinology and Metabolic Unit at Fondazione Ospedale Maggiore IRCCS, and L Persani is Associate Professor of Endocrinology at the University of Milan and Director of the Laboratory of Endocrinological Research, Istituto Auxologico Italiano IRCCS, Milan, Italy.

Correspondence to: Paolo Beck-Peccoz¹ Endocrinology and Metabolic Unit, Fondazione Ospedale Maggiore IRCCS, Padiglione Granelli, Via F. Sforza 35, 20122 Milan, Italy
Email: paolo.beckpeccoz@unimi.it

Received 25 May 2006 | Accepted 13 July 2006