Persistent Rhinosinusitis-Like Symptoms Revealing a Lactotroph Pituitary Neuroendocrine Tumour: A Case Report.

Pituitary neuroendocrine tumours (PitNETs) commonly present with symptoms related to mass effect or hormonal dysfunction, including headache, visual disturbances, and endocrine abnormalities. However, atypical presentations without neurological or hormonal "red flag" symptoms may delay diagnosis, particularly in primary care settings where benign upper respiratory conditions are more frequently encountered. We report the case of a 56-year-old postmenopausal woman who presented with a five-month history of persistent postnasal drip, chronic non-productive cough and a sensation of nasal congestion characterised by fullness in the nasal and retro-orbital region. Despite conservative medical management, persistent symptoms prompted a computed tomography (CT) of the brain and paranasal sinuses, which unexpectedly revealed a sellar mass extending into the left sphenoid sinus. Subsequent magnetic resonance imaging (MRI) confirmed a 3.4cm pituitary macroadenoma with left cavernous and sphenoid sinus invasion, left internal carotid artery encasement, optic nerve involvement, and imaging features of pituitary apoplexy. Hormonal evaluation showed hyperprolactinaemia, and histopathology following endoscopic endonasal resection confirmed a lactotroph PitNET. This case highlights the importance of diagnostic reassessment in patients with persistent symptoms and demonstrates that clinically significant PitNETs can masquerade behind common benign upper respiratory conditions.