Endocrine Abstracts

Case presentation: A 60-year-old gentleman presented with altered vison. Past medical history included ulcerative colitis, henoch-schonlein purpura (HSP) and Graves’ disease. Family history included a brother that underwent surgery for a pituitary macroadenoma. Pituitary MRI identified a 27 × 16 × 20 mm macroadenoma with chiasmal compression. Perimetry demonstrated bitemporal hemianopia. Clinical assessment showed no stigmata of endocrinopathy. Pituitary function tests were normal apart from hypogonadotrophic hypogonadism and testosterone replacement was initiated. The patient underwent trans-sphenoidal surgery. Post-operative pituitary MRI showed near total resection with minimal residuum and the patient remains well with stable pituitary function. Surprisingly, histology revealed a densely granulated (silent) corticotroph pituitary neuroendocrine tumour containing giant cell non-necrotising granulomas. Additional stains for associated infective organisms were negative. Histological samples did not contain normal pituitary tissue and therefore a diagnosis of granulomatous hypophysitis (GRH) could not be confirmed. Investigations for vasculitis, connective tissue diseases, sarcoidosis and IgG4 disease were negative and a whole-body CT ruled out systemic inflammation. Dual pathology within a pituitary is extremely rare and has only been reported in a few case reports and series. Interestingly, typical clinical and radiological features associated with hypophysitis were absent in this patient. In this patient, a background of inflammatory and autoimmune disorders raised the possibility of a systemic inflammatory disorder. Indeed, GRH in patients with Crohn’s disease has previously been described. Interestingly, Force et al., report that hypophysitis remission was achieved with anti-TNF-α therapy, suggesting a shared underlying pathophysiological mechanism (1). However, ulcerative colitis is typically diagnosed in the absence of granuloma, therefore a shared inflammatory mechanism may be less likely in our case. It is also postulated that GRH may be triggered by autoantibodies against non-secretory pituitary proteins, leading to local immunological mechanisms within pituitary adenomas may drive granulomata formation, independent of systemic signals (2). This rare presentation of dual pathologies highlights the difficult nature of diagnosis and investigation of pituitary lesions. Attention is needed to identify such cases as separate treatments may be required. In this patient, we hypothesise that secondary granuloma may have developed in relation to local intra-adenoma mechanisms, with an alternative hypothesis of systemic inflammation related to inflammatory bowel disease