Endocrine Abstracts

Pituitary sarcoidosis is a rare form of neurosarcoid, commonly associated with multisystemic sarcoidosis. The most common intracranial site of sarcoidosis leading to endocrine involvement is the hypothalamus and the pituitary gland. The prevalence of hypothalamic–pituitary involvement in multisystemic sarcoiosis is reported to be around 5%.

Granulomatous infiltration of the hypothalamus and the pituitary gland always results in endocrine disorder, GH deficiency and diabetes insipidus in about 40% of cases.

We report a case of pituitary sarcoid without the multi-organ involvement typical observed in systemic sarcoidosis.

Case report: A 24-year-old male presented with 2 months history of headache, fatigue, loss of libido, polyuria and polydipsia. Clinical examination revealed multiple enlarged lymph nodes within the neck. Visual field assessment showed a bitemporal hemianopia. A Computed Tomogram scan revealed mediastinal, hilar and retroperitoneal lymph nodes.

Endocrine tests confirmed diabetes insipidus and panhypopituitarism with undetectable gonadotrophins, low testosterone, cortisol, free thyroxine, and insulin-like growth factor 1.

A pituitary MRI demonstrated an enhancing intrasellar and suprasellar mass in contact with the optic chiasm. There was a loss of the pituitary bright spot.

A lymph node biopsy was performed which revealed well formed non-caseating epitheloid granulomas with numerous giant cells. Ziehl-Nielson staining for mycobacteria and PAS staining for fungi were all negative. A diagnosis of sarcoidosis was made based on clinical, biochemical and histology results.

He was commenced on high dose cortisosteroids, anterior and posterior pituitary hormone replacement with levothyroxine, testogel, hydrocortisone and desmopressin.

Clinical course: Two months after the initial presentation, and the initiation of steroid, the patient described significant improvement in his symptoms. A repeat visual field examination was normal. A follow up pituitary MRI revealed a marked reduction in the bulk of the pituitary mass.