ENDOCRINE TUMOURS: Thyrotropin-secreting pituitary adenoma: a structured review of 535 adult cases

Abstract

Background and Aims: Thyrotropin-stimulating pituitary adenoma (TSHoma) are a rare entity, occurring in 1 per million people. We performed a systematic review of 535 adult cases summarizing the clinical, biochemical, hormonal and radiological characteristics of TSHoma. Furthermore, we discuss the current guidelines for diagnosis and treatment. Methods A structured research was conducted using Pubmed with the following MeSH terms: “thyrotropin secreting pituitary adenoma” OR “TSHoma” OR “thyrotropinoma”. Results Our analysis included 535 cases originating from 18 case series, 5 cohort studies and 91 case reports. Mean age at diagnosis was 46 years. At presentation 75% had symptoms of hyperthyroidism, 55.5% presented with a goitre and 24.9% had visual field defects. Median TSH at diagnosis was 5.16 (3.20-7.43) mU/L with a mean fT4 of 41.5±15.3 pmol/L. The majority (76.9%) of the TSHoma were macroadenoma. Plurihormonality was seen in 37.4% of the adenoma with a higher incidence in macroadenoma. Surgical resection of the adenoma was performed in 87.7% patients of which 33.5% had residual pituitary adenoma. Postoperative treatment with a somatostatin analogue led to a stable disease in 81.3% of the cases with residual tumour. We noticed a significant correlation between the diameter of the adenoma and residual pituitary adenoma (r=0.490, p<0.001). However, in patients pre-operatively treated with somatostatin analogue this correlation was absent. Conclusion TSHoma are a rare cause of hyperthyroidism and are frequently misdiagnosed. Based on our structured analysis of case series, cohort studies and case reports, we conclude that the majority of TSHoma are macroadenoma being diagnosed in the 5-6th decade of life and presenting with symptoms of hyperthyroidism. Plurihormonalitiy is observed in one third of TSHoma. Treatment consists of neurosurgical resection and SSA in case of surgical failure.

Clinical and Therapeutic Characteristics of Pituitary TSH-Secreting Adenoma in Adolescent-Onset Patients: Six Case Studies and Literature Review

“…Arrhythmia and valvular diseases were seen in more than 30% of the TSH-oma cases at our center. Recently, a meta-analysis revealed that atrial fibrillation or heart failure happened in 11.1% of 535 adult TSH-oma cases ( 22 ). Another research found that TSH-oma can significantly induce left atrial enlargement and subclinical atrial fibrillation since excess thyroid hormones can increase the arrhythmogenic activity of the pulmonary veins, and increase the hemodynamic load ( 23 ).…”

Current and Emerging Medical Therapies in Pituitary Tumors

“…They represent a rare cause of central hyperthyroidism characterized by normal or inappropriately high Thyroidstimulating hormone (TSH) concentrations in the presence of elevated free-thyroid hormones (fT3 and fT4) [111]. The treatment of choice for TSHomas is surgery, with a complete resection of the tumor achieved in two-thirds of patients [112]. The rather disappointing results of surgery (especially for the frequently detected macroadenomas) indicate that additional treatment, such as radiotherapy or medical treatment, may be necessary.…”

Long action somatostatin analogues in patients with TSH-secreted pituitary adenomas: treatment experience

“…[7]. К настоящему времени в литературе опубликовано около 535 случаев ТТГ-секретирующих аденом гипофиза [8]. Благодаря использованию в клинической практике высокочувствительных иммунометрических методов определения ТТГ, а также широкой доступности МРТ и КТ, частота выявления тиреотропином постепенно увеличивается [9].…”

“…По данным Р. Beck-Peccoz и соавт., около 25% тиреотропином обладают смешанной секрецией, чаще встречается сочетание гиперсекреции ТТГ и соматотропного гормона (СТГ) (18,3%), реже -ТТГ и пролактина (9,7%) и крайне редко -ТТГ и гонадотропных гормонов (1,7%) [12]. При этом в других исследованиях косекреция ТТГ и других гормонов гипофиза наблюдалась примерно в 40% случаев, в 55% которых выявлена коэкспрессия с СТГ, а в 40% -коэкспресия с пролактином [8,13]. Следует отметить, что положительная иммуноэкспрессия, выявленная по данным иммуногистохимического исследования, не всегда сопровождается повышением концентрации гормонов в крови.…”