Short-term Preoperative Octreotide for Thyrotropin-secreting Pituitary Adenoma

Abstract

Background:Thyrotropin-secreting pituitary adenomas (TSHomas) are a rare cause of hyperthyroidism. Somatostatin (SST) analogs work by interacting with somatostatin receptors (SSTRs). This study aimed to evaluate short-term preoperative octreotide (OCT) use in TSHoma patients and to investigate SSTR2 and SSTR5 expression and observe structural changes in tumor tissue.Methods:We reviewed records and samples from eight TSHoma patients treated between July 2012 and July 2015. We tested immunohistochemically for SSTR2/5 expression and examined TSHoma cells for morphological changes. Signed rank sum test was used to compare the efficacy of short-term preoperative OCT treatment.Results:OCT treatment (median time: 7.9 days, range: 3–16 days; median total dose: 1.8 mg, range: 0.9–4.2 mg) led to significant decrease in all patients’ thyroid hormone levels (FT3 [nmol/L]: 8.33 [7.02, 12.29] to 4.67 [3.52, 5.37] [P = 0.008]; FT4 [pmol/L]: 25.36 [21.34, 28.99] to 16.66 [14.88, 21.49] [P = 0.016]; and TSH [μU/ml]: 5.80 [4.37, 6.78] to 0.57 [0.19, 1.24] [P = 0.008]). All the eight tumor specimens expressed high SSTR2 protein levels; 5/8 expressed high SSTR5, but 3/8 that expressed low SSTR5 presented a significantly higher TSH suppression rate (P = 0.036). Electron microscopy showed subcellular level impairments, including clumped nuclear chromatin and reduced cytoplasmic volume. Golgi complexes were observed in the OCT-treated TSHoma specimens.Conclusions:OCT can control hormone levels and damage the ultrastructure of tumor cells and organelles. Short-term response to OCT may be related to SSTR5 expression. Preoperative SST analog treatment for TSHoma could be considered as a combination therapy.

Tirotoksikozun Nadir Bir Nedeni: TSH Salgılayan Hipofiz Adenomu

“…Kavernöz sinüs invazyonunun sık olması ve fibroz içeriğin fazla olması adenomun cerrahi olarak tamamen çıkarılmasını güçleştirmektedir 3 . Makroadenomlarda cerrahi remisyon oranları %50-60 civarındadır 14 . Hastanın cerrahiye hazırlanmasında ya da cerrahinin yetersiz olduğu durumlarda medikal tedavi kullanılabilir.…”

The outcome of TSHoma from a tertiary care institute in India

“…In larger series of TSHoma, 15–30% microadenomas have been reported. [ 10 , 11 ] This finding is of great significance as the incidence of pituitary incidentaloma is also similar, thereby reducing the specificity of pituitary imaging in the diagnosis of TSHoma. However, in the current study, macroadenomas on imaging in conjunction with biochemical and clinical profiles, aided in the diagnosis of TSHoma.…”

“…[ 21 ] Preoperative preparation with somatostatin analogs (SSA) and ATDs along with beta-blockers has been used to make the patient euthyroid and reduces the adenoma size. [ 10 ] Both octreotide LAR ( n = 3) and anti-thyroid drugs ( n = 6) were used in our cases preoperatively and 7/8 cases underwent TSS.…”

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

“…Экспрессия рецепторов к дофамину и тиреотропин-рилизинг-гормону (ТРГ) может сильно варьировать. Рецепторы к соматостатину встречаются в большинстве случаев тиреотропином, что обусловливает эффективность использования аналогов соматостатина у данной группы пациентов [6,[14][15][16][17].…”