Primary Granulomatous Hypophysitis Presenting with Secondary Hypothyroidism

Abstract

Objective: We present a case of a 45-year-old woman with history of Graves disease treated with thyroidectomy who developed panhypopituitarism due to granulomatous hypophysitis.Methods: The details of the case presentation, evaluation, diagnosis, and treatment are reviewed. On routine follow-up visits for thyroid condition, the patient complained of symptoms of hyperthyroidism, despite being on a previously adequate dose of levothyroxine. Work-up led to the diagnosis of hypophysitis.Results: The patient responded to corticosteroid therapy, but 5 months later, magnetic resonance imaging of the brain showed recurrence of the disease. Eventually, the patient underwent partial transsphenoidal hypophysectomy, later developed recurrence of disease, and had total hypophysectomy. The postoperative pathology report was consistent of granulomatous hypophysitis.Conclusion: Granulomatous hypophysitis is an uncommon inflammatory disease affecting the pituitary. It is commonly misdiagnosed as a macroadenoma because of its clinical presentation. (AACE Clinical Case Rep. 2018;4:e329-e333) Abbreviations: FT4 = free thyroxine; GH = granulomatous hypophysitis; LH = lymphocytic hypophysitis; MRI = magnetic resonance imaging; TSH = thyroid-stimulating hormone CASE REPORTHypophysitis is a rare inflammatory process of the pituitary gland that mimics pituitary macroadenomas. It can be idiopathic or manifest as a part of a systemic autoimmune disease. Granulomatous hypophysitis (GH) and lymphocytic hypophysitis (LH) are the most common subtypes reported in literature (1-3). We present a case of a 45-year-old female with past medical history of hypothyroidism after total thyroidectomy for Graves disease and surgical history of hysterectomy. On presentation, she complained of hyperthyroid symptoms (e.g., fatigue, excess sweating, hot flashes, presyncope, weight loss, and headaches), despite being on a previously adequate levothyroxine dose. Two months prior, her thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were normal. Her physical exam was unremarkable except for a surgically absent thyroid. Laboratory evaluation revealed TSH <0.006 mU/L (normal range, 0.34 to 5.6 mU/L) and FT4 of 1.1 ng/dL (normal range, 0.58 to 1.64 ng/dL); thus, her levothyroxine dose was decreased. Despite this, she continued to have symptoms and low TSH. Secondary hypothyroidism was suspected, as TSH was undetectable and FT4 0.47 ng/dL off levothyroxine. Severe headache, insomnia, and worsening fatigue developed, so imaging was done and magnetic resonance imaging (MRI) revealed a large bilobed enhancing pituitary mass with suprasellar extension and thickening of the pituitary stalk (Fig. 1). Laboratory results showed low am cortisol, estrogen, follicle-stimulating hormone (FSH), insulin-like growth factor See accompanying article, p. e350.

Updating the Rainbow of Flavors of Hypophysitis

“…These new colors in the rainbow of hypophysitis include primary IgG4related pituitary disease and secondary hypophysitis as an oncologic immunotherapy-related endocrinopathy. The case of primary hypophysitis described in this issue of AACE Clinical Case Reports by Dr. Antonios et al (12) further highlights the heterogeneity inherent in the natural history of hypophysitis and underscores the lack of both established diagnostic criteria and evidence-based treatment approaches. Although there is a wide spectrum of subtypes of hypophysitis, it is still a rare disease, and best practice guidelines are needed to determine the most optimal strategies for evaluation and management.…”

“…In this issue of AACE Clinical Case Reports, Dr. Antonios and colleagues (12) reveal another facet of heterogeneity associated with hypophysitis, in the manner of presentation. The authors focus attention on primary hypophysitis proven with histopathology to be granulomatous hypophysitis, presenting atypically and with a recurrent course.…”