Pituitary Hyperplasia Due to Longstanding Primary Hypothyroidism: A Case Report and Comprehensive Review of the Literature.

Hypothyroidism is a frequently diagnosed endocrine disorder. Common signs and symptoms include fatigue, cold intolerance, hoarseness, dry skin, constipation, a slow relaxation phase of deep tendon reflexes, and bradycardia. However, some patients may exhibit atypical signs and symptoms, which can result in diagnostic confusion. Pituitary hyperplasia resulting from longstanding primary hypothyroidism was first described by Niepce in 1851. It is usually asymptomatic, but sometimes, in addition to symptoms of overt hypothyroidism, patients may complain of headaches, hypopituitarism, visual field impairment, and hyperprolactinemia. Furthermore, on imaging, pituitary hyperplasia can be mistaken for a pituitary adenoma. Distinguishing between the two is crucial, as their management differs; the former often responds to thyroid hormone replacement therapy, while the latter might need treatment with surgery and/or radiotherapy. Here we describe a patient who developed pituitary hyperplasia in the setting of longstanding uncompensated primary hypothyroidism due to a lack of compliance with levothyroxine replacement therapy. We also review the clinical, laboratory, and radiologic findings of the case reports available in the literature up to now in order to improve the knowledge and the care of the disease.

Immune-related thyroid dysfunctions during anti PD-1/PD-L1 inhibitors: new evidence from a single centre experience.

The role of anti-thyroid peroxidase antibodies (anti-TPO Abs) in the development of abnormal thyroid function tests (DYSTHYR) during treatment with immune checkpoint inhibitors (ICIs) is not fully understood; moreover, controversial data exist about the relationship between ICI-related thyroid dysfunction (TD) and survival. We retrospectively analyzed the onset or the worsening of DYSTHYR in patients treated with programmed cell death protein-1 (PD-1) or its ligand (PD-L1) inhibitors between 2017 and 2020. In patients without previous TD, we focused on the association between baseline anti-TPO Abs level and DYSTHYR. Furthermore, the relationship between DYSTHYR and progression-free survival (PFS) or overall survival (OS) was explored. We included 324 patients treated with anti PD-1 (95.4%) or anti PD-L1 inhibitors. After a median of 3.3 months, DYSTHYR was registered in 24.7%, mostly hypothyroidism alone (17%). Patients with pre-existing TD (14.5% of the sample) were at higher risk of DYSTHYR compared to patients without previous TD (adjusted OR 2.44; 95% IC 1.26-4.74). In patients without known previous TD, high anti-TPO Abs level, even below the positivity cut-off, was a risk factor for developing DYSTHYR (adjusted OR 5.52; 95% IC 1.47-20.74). DYSTHYR was associated with a longer 12-month OS (87.3% vs 73.5%, p = 0.03); no statistically significant difference in terms of PFS was observed between the DYSTHYR+ and DYSTHYR- group. DYSTHYR is common during anti PD-1/anti PD-L1 treatment, especially in patients with pre-existing TD. In subjects without known previous TD, high anti-TPO Abs level at baseline can be a predictive biomarker of DYSTHYR. An improved OS is observed in patients with anti PD-1/anti PD-L1-induced DYSTHYR.