A challenging TSH/GH co-secreting pituitary adenoma with concomitant thyroid cancer; a case report and literature review

Abstract

Background Thyroid stimulating hormone (TSH) secreting pituitary adenoma (TSHoma) with coexisting thyroid cancer is extremely rare, and proper treatment of both diseases may pose a unique clinical challenge. When TSHoma has plurihormonality, particularly involving the co-secretion of growth hormone (GH), management can be more complicated. Herein, we present a difficult-to-manage case of papillary thyroid cancer with an incurable TSH/GH-secreting pituitary adenoma. Case presentation A 59-year-old man was referred to our hospital due to memory impairment and inappropriate TSH level. Sella magnetic resonance imaging revealed a huge pituitary mass extending to the suprasellar area. Clinical diagnosis of TSH/GH co-secreting pituitary adenoma was made based on elevated free T4, total T3, serum α-subunit, insulin-like growth factor-1 levels and non-suppressible GH levels after oral glucose loading. Rectal cancer and multifocal papillary thyroid microcarcinoma (PTMC) were diagnosed during initial screening for internal malignancy; lower anterior resection was performed and close observation was planned for PTMC. Long-acting octreotide therapy was commenced, which resulted in a dramatic reduction in TSHoma size and facilitated control of hormonal excess. Total thyroidectomy and radioactive iodine (RAI) therapy were needed during follow up due to the growth of PTMC. After the surgery, the pituitary adenoma represented resistance to somatostatin analogue therapy and the tumor size gradually increased despite the addition of dopamine agonist therapy. Furthermore, TSH suppressive therapy with levothyroxine was impossible and an adequate TSH level for RAI therapy was unmountable. Late debulking pituitary surgery was ineffective, and the patient gradually deteriorated and lost to follow up. Conclusion We report the first aggravated case of TSH/GH co-secreting pituitary tumor after total thyroidectomy for concomitant multifocal PTMC. Deferring of thyroid surgery until the TSHoma is well controlled may be the optimal therapeutic strategy in patients with TSHoma and coexistent thyroid cancer; ablative thyroid surgery may result in catastrophic pituitary tumor growth.

Clinical features and therapeutic outcomes of GH/TSH cosecreting pituitary adenomas: experience of a single pituitary center

“…All the included GH/TSH cosecreting PAs were macroadenomas, and nearly one-quarter of the PAs were giant adenomas. The mixed PA group presented with a larger median maximum diameter and more cavernous sinus invasion than the age- and sex-matched GH monosecreting PA group, verifying the deductions from a few researchers that PIT-1 lineage plurihormonal PAs are frequently large, and they are also more invasive than mono-secreting PAs ( 12 , 14 , 29 ). The overexpression of PIT-1 is possibly related to cell proliferation in GHPAs, PRLomas and TSHomas, even though the pathophysiological mechanism has not been fully investigated ( 14 , 30 ).…”

“…One patient was diagnosed with papillary thyroid carcinoma and underwent thyroid lobectomy. Mixed PAs complicated with thyroid cancer have rarely been reported and are challenging to treat because of the complex interactions between hormones ( 12 , 18 ). Hence, clinicians should be vigilant to screen the thyroid and prevent misdiagnosis.…”

SFRP2 is a Novel Diagnostic Biomarker and Suppresses the Proliferation of Pituitary Adenoma

“…is is because PAs do not typically present with the typical symptoms that are associated with hormone hypersecretion [6,7]. On the other hand, certain tumors have the potential to spread to the cavernous sinus or the region around the internal carotid artery, making it hard to do a total excision [8]. Surgical treatment is bene cial for NFPAs; however, complete removal of certain tumors is not achievable.…”

Correlation analysis of serum thyroglobulin, thyroid-stimulating hormone levels, and thyroid-cancer risk in thyroid nodule surgery

“…Some studies have demonstrated a potential correlation between TSH and the risk of thyroid cancer[ 27 ]. Elevated TSH levels are considered a risk factor for thyroid cancer as they can stimulate the proliferation and malignant transformation of thyroid cells[ 28 ]. However, not all studies have yielded consistent results, and some studies have failed to establish a conclusive association between TSH and thyroid cancer.…”