Development of Marine-Lenhart Syndrome during the Course of Acromegaly.

A 76-year-old woman was diagnosed with acromegaly and underwent resection of a transsphenoidal pituitary tumor. Central hypothyroidism was detected before surgery and the patient was treated with levothyroxine. Insulin-like growth factor-1 (IGF-1) levels remained abnormal after surgery. Follow-up showed an increase in free thyroxine levels even after discontinuation of levothyroxine; thereafter, Marine-Lenhart syndrome was diagnosed. The initiation of treatment with a somatostatin analog for acromegaly and thiamazole for Marine-Lenhart syndrome was followed by normalization of IGF-1 levels and thyroid function test results. Coexistent thyrotoxicosis is rare in patients with acromegaly; therefore, attention should be paid to elderly patients, as they exhibit only a few symptoms.