Case
A 29-year-old female was referred to endocrinology for management of type-1 diabetes, and secondary amenorrhoea was noted. Her past medical history included type-1 diabetes, hypercholesterolaemia, and depression.
She had a history of chronic headaches, with no acute deterioration. Visual assessment revealed right sided temporal visual field deficit. Investigations showed suppressed gonadotrophins and growth hormone, with the remainder of the pituitary panel being unremarkable (table 1).
An MRI pituitary demonstrated a 15x18x24mm haemorrhagic cystic mass arising from the pituitary fossa, most likely a cystic pituitary macroadenoma (image 1).
She was referred to the neurosurgical team, who proceeded with transsphenoidal resection. Histopathology showed cholesterol clefts with surrounding histiocytes including multinucleated giant cells with haemosideron deposition, in keeping with a cholesterol granuloma.
Her post-operative course was free of complications, with no new hormonal replacement requirements. Her visual symptoms have subjectively improved, but she is yet to complete a formal visual field assessment.
Discussion
Cholesterol granulomas are a rare cause of cystic pituitary lesions, representing less than 1% of pituitary tumours [1]. The exact origin remains unclear, and distinguishing them from other cystic pituitary pathologies continues to be challenging [1,2].
Histological features include presence of cholesterol clefts, fibrosis, multinucleated giant cells and haemosiderin deposits [3]. Visual disturbance or endocrinological deficiencies are the most common presenting features [2,4]. MRI findings are varied, with hyperintensity on T1 weighted imaging and hypointensity on T2 weighted imaging being most frequent [4].
Operative management is recommended, and post-operatively patients should have improvement of visual deficits [4]. Despite often incomplete resection there is minimal risk of recurrence, however pituitary hormonal function rarely recovers [1,4].
Our patient has continued to have elevated cholesterol and suboptimal control of her type-1 diabetes, but the literature did not suggest these were contributing factors in the formation of cholesterol granulomas.