Endocrine Abstracts

Case history: A 54-year-old man was admitted with a history of syncopal episodes. Orthostatic hypotension led to an endocrine referral and subsequent diagnosis of pan-anterior hypopituitarism but with no evidence of posterior pituitary involvement. Although an initial aetiological diagnosis remained elusive, further work-up (see below) led to a histology-confirmed diagnosis of ACE-negative neurosarcoidosis. This diagnostic conundrum could have been contributed by a prior neurological diagnosis of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) which was later revoked to neurosarcoidosis due to endocrine involvement. Following replacement with hormones, there was a remarkable improvement in the patient’s quality of life.

Investigations: Pituitary profile: showed secondary adrenocortical deficiency (ACTH <5 ng/l, cortisol <25 nmol/l); gonadotrophin deficiency (both FSH & LG <1 u/l); sommatotroph deficiency (paired IGF-1 <6 & GH −0.30 ug/l) and normal prolactin – 483 miu/l. Posterior pituitary osmolality data was normal. MRI showed white matter, basal ganglia and brainstem hyperintensities but with normal pituitary morphology. We however felt that despite the lack of posterior pituitary dysfunction, the pituitary stalk appeared inappropriately thickened and hence worthy of further investigations into an aetiological diagnosis – especially systemic infiltrative disorders. Vasculitis screen was negative and so was IgG4 and Aquaporin 4 antibody. ACE levels were thrice negative. CSF studies did not show oligoclonal bands. PET-CT scan demonstrated small volume FDG-avid mediastinal and hilar lymphadenopathy which on biopsy showed non-caseating granulomatous sarcoidosis. It would be worthwhile to mention that based on initial presentation of optic atrophy and slurred speech two years prior to this presentation, neurology had made a former diagnosis of ‘Clinical CADASIL’ but it was noted that genetics for the same were negative and so was skin biopsy.

Results and treatment: Following histological confirmation, neurology revisited their previous diagnosis and agreed to treat the patient as neurosarcoidosis with azathioprine and prednisolone. This has led to significant improvement in his vision and motor-sensory disabilities. Furthermore, hormonal supplementation in the form of growth hormone, levothyroxine and testosterone has further improved the quality of life. He now has no use of crutches!

Conclusions and points for discussion: This complex presentation of pan-anterior hypopituitarism demonstrates that it is important to look for an aetiological diagnosis rather than simply treating deficiencies. Furthermore, neurological involvement in sarcoidosis including pituitary dysfunction occurs in only 5–10% of patients, needing a high degree of clinical suspicion and can be missed by simply relying on negative ACE levels.