Thyrotropin-secreting pituitary adenomas: epidemiology, diagnosis, and management

Abstract

Inappropriate secretion of TSH was first described in 1960 in a patient with evidence of hyperthyroidism and expanded sella on imaging. It was later found that a type of pituitary adenoma that secretes TSH (thyrotropinoma) was the underlying cause. The objective of the present review article is to summarize data on the epidemiology, pathogenesis, diagnosis, and management of thyrotropinomas. The prevalence of thyrotropinomas is lower than that of other pituitary adenomas. Early diagnosis is now possible thanks to the availability of magnetic resonance imaging and sensitive laboratory assays. As a corollary, many patients now present earlier in the course of their disease and have smaller tumors at the time of diagnosis. Treatment also has evolved over time. Transsphenoidal surgery is still considered definitive therapy. Meanwhile, radiation therapy, including radiosurgery, is effective in achieving tumor control in the majority of patients. In the past, radiation therapy was used as second line treatment in patients with residual or recurrent tumor after surgery. However, the availability of somatostatin analogs, which can lead to normalization of thyroid function as well as shrink these tumors, has led to an increase in the role of medical therapy in patients who are not in remission after pituitary surgery. In addition, dopamine agonists have shown some efficacy in the management of these tumors. Better understanding of the molecular pathogenesis of thyrotropinomas may lead to rationally designed therapies for patients with thyrotropinomas.

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

“…SRLs are used for the treatment of TSH-oma [2, 41, 42]. In our study, presurgical medical treatment with SRLs, but not that with methimazole, was associated with a lower prevalence of VFs.…”

“…Accordingly, vertebral morphometry should be performed both at baseline and during follow-up in patients with TSH-oma. Finally, a relevant number of patients with TSH-oma are not cured by neurosurgery with a consequent relapse of hyperthyroidism [2, 42, 55–57]. Based on the preliminary results of our study, SRL treatment may be proposed in all those patients with active disease in place of methimazole for these apparent favorable effects on skeletal health.…”

“…Over the past decades, the incidence and prevalence of TSH-oma have increased due to improved awareness of disease and standardization of diagnostic approaches [2]. …”

Hyperthyroxinemia with a non-suppressed TSH: how to confidently reach a diagnosis in this clinical conundrum

“…They are the least common form of functional pituitary adenoma accounting for only around 2% of all pituitary tumors diagnosed [7,8]. The incidence of TSHoma has increased, likely due to improvements in biochemical and imaging modalities allowing more accurate diagnosis [9][10][11][12]. While these tumors are almost invariably benign, they are often large invasive fibrous tumors at the time of resection.…”

Thyrotoxicosis: Diagnosis and Management

“…Frequently, there are also symptoms generated through local compression by the tumor (headaches and visual field defects). 94 This diagnosis should also be considered in patients with presumed primary hypothyroidism in whom TSH does not normalize with LT 4 therapy. 95 Pituitary imaging with magnetic resonance is the next step, and the most common presentation of a TSHproducing adenoma is a macroadenoma.…”