Somatostatin Analogue Treatment of a TSH-Secreting Adenoma Presenting With Accelerated Bone Metabolism and a Pericardial Effusion

Abstract

Increased bone turnover and other less frequent comorbidities of hyperthyroidism, such as heart failure, have only rarely been reported in association with central hyperthyroidism due to a thyrotropin (TSH)-secreting pituitary adenoma (TSHoma). Treatment is highly empirical and relies on eliminating the tumor and the hyperthyroid state.We report here an unusual case of a 39-year-old man who was initially admitted for management of pleuritic chest pain and fever of unknown origin. Diagnostic work up confirmed pericarditis and pleural effusion both refractory to treatment. The patient had a previous history of persistently elevated levels of alkaline phosphatase (ALP), indicative of increased bone turnover. He had also initially been treated with thyroxine supplementation due to elevated TSH levels. During the diagnostic process a TSHoma was revealed. Thyroxine was discontinued, and resection of the pituitary tumor followed by treatment with a somatostatin analog led to complete recession of the effusions, normalization of ALP, and shrinkage of pituitary tumor.Accelerated bone metabolism and pericardial and pleural effusions attributed to a TSHoma may resolve after successful treatment of the tumor. The unexpected clinical course of this case highlights the need for careful long-term surveillance in patients with these rare pituitary adenomas.

High Prevalence of Radiological Vertebral Fractures in Patients With TSH-Secreting Pituitary Adenoma

“…Bone resorption was shown to be increased in patients with TSH-oma, with comparable values to those seen in primary hyperthyroidism and closely correlated to serum thyroid hormone levels [14]. Consistently, normalization of bone turnover was observed after treatment of TSH-oma [13]. However, in only one case report, data on fractures were reported [15].…”

“…, suppressed TSH values in primary hyperthyroidism and inappropriately either normal or high TSH values in secondary hyperthyroidism). Due to rarity of the disease, studies on bone involvement in TSH-oma are few and limited to evaluation of biochemical markers of bone turnover [ 13 , 14 ]. Bone resorption was shown to be increased in patients with TSH-oma, with comparable values to those seen in primary hyperthyroidism and closely correlated to serum thyroid hormone levels [ 14 ].…”

“…However, when thyroid hormones increase, bone remodeling is excessively stimulated with consequent bone loss, a decrease in bone mineral density (BMD), and an increase in vertebral and nonvertebral fracture risk [ 9–12 ]. Different from primary hyperthyroidism, only very few studies investigated the impact of secondary hyperthyroidism on skeletal end points, with data being limited to the evaluation of biochemical markers of bone turnover [ 13 , 14 ], whereas the paucity of data on BMD and fracture risk is striking [ 15 ].…”