Primary hypothyroidism-associated TSH-secreting pituitary adenoma/hyperplasia presenting as a bleeding nasal mass and extremely elevated TSH level

Abstract

A 41-year-old male with primary hypothyroidism and a huge TSH-secreting pituitary tumor presented with a bleeding nasal mass that was initially misdiagnosed as a paraganglioma. Other unique features of the case include lack of complaints related to hypothyroidism, an extremely elevated TSH level of 3474 mU/l, and a low prolactin level. The presence of primary hypothyroidism made differentiating TSH-secreting pituitary adenoma from secondary thyrotroph hyperplasia difficult. A low molar ratio of alpha-subunit to TSH on presentation, together with normalization of TSH level and a 50% reduction in the size of the tumor after 6 weeks of thyroxine replacement therapy, suggested the presence of thyrotroph hyperplasia. However, the lack of further decrease in the size of the tumor that was associated with increased metabolic activity on 18-FDG PET scan, intense uptake on octreotide scan, and an elevated alpha-subunit to TSH molar ratio despite the normalization of free T4 and TSH levels for 16 months suggested the coexistence of thyrotroph adenoma. Together, the findings support the view that thyrotroph adenoma/irreversible hyperplasia can result from long standing primary hypothyroidism.

A Thyroid-stimulating Hormone (TSH) Producing Adenoma in a Patient with Severe Hypothyroidism: Thyroxine Replacement Reduced the TSH Level and Tumor Size

“…All tumors were macroadenomas including a huge one. 8) The TSH levels were much higher (7.5-3474 μIU/mL) than that of TSH-producing adenomas without hypothyroidism: the median and interquartile range was 3.08 and 1.82-4.44 μIU/mL, respectively, in a series of 90 patients. 5) A significant reduction in the TSH level elicited by thyroxine replacement therapy was documented in two reports.…”

“…Our search of the literature found only seven reports of patients manifesting this coexistence since 1996. [7][8][9][10][11][12][13] Their hypothyroidism was attributed to autoimmune thyroiditis in six patients and to thyroid lobectomy to address a benign tumor in one patient. All tumors were macroadenomas including a huge one.…”

Epistaxis as first clinical presentation in a child with giant prolactinoma: Case report and review of literature

“…Other reported causes of epistaxis related to pituitary tumors are an aggressive TSH-secreting adenoma,[11] extensive acidophil-stem-cell adenoma. [10] In patients with acromegaly[12] and another case of rupture of an intratumoral aneurysm enclosed in a large prolactinoma resulting in fatal epistaxis.…”

Cushing's disease in a patient with steroid 21-hydroxylase deficiency

“…A review of the literature demonstrates that hyperplasia or tumors of the pituitary can be found in the context of long-standing hypothyroidism and adrenal insufficiency due to Addison's disease or after bilateral adrenalectomy [19][20][21][22][23][24][25][26][27][28].…”