Endocrine Abstracts

Case history: A male patient presented to the Endocrine clinic age 64, with an 18-year history of erectile dysfunction. He was treated under Urology with phosphodiesterase inhibitors and Nebido injections for hypogonadism. Notably the cause of hypogonadism had not been established. The patient was concurrently reviewed by Oral Medicine due to a 2.5-year history of xerostomia, and Dermatology for a non-healing, erythematous, pruritic lesion on his right lower leg and several white/pink polycyclic patches over the left upper arm. The patient had also been receiving levothyroxine for 10 years for presumed primary hypothyroidism.

Investigations: When under Urology, morning serum testosterone was found reduced at 4.9 nmol/l (reference range 8.0–30.0). Gonadotrophins and SHBG were not tested at that time. Following endocrine review, and whilst on Nebido, investigations for hypogonadism were as expected (testosterone 8 nmol/l; LH<0.3 IU/l; FSH<0.3 IU/l; SHBG 42 nmol/l). The anterior pituitary hormone profile revealed low IGF-1 (3.9 nmol/l; reference range 10.1–28.4), low morning cortisol (129 nmol/l), normal prolactin, TSH <0.05 mIU/l and free T4 of 13.6 pmol/l (on Levothyroxine). The patient was commenced on Hydrocortisone and a subsequent Glucagon stimulation test confirmed GH and ACTH deficiencies (peak GH 0.1 mcg/l; peak cortisol 202 nmol/l). A water deprivation test showed no evidence of diabetes insipidus. During investigations for xerostomia, a raised ACE was found on two occasions. Biopsy of the upper arm cutaneous lesions showed multiple non-caseating granulomas in the dermis consistent with sarcoidosis. A contrast pituitary MRI scan showed an ill-defined, small volume, soft tissue enhancement in the hypothalamic region, in keeping with neurosarcoid. No pituitary lesions were identified. Serum and urinary calcium were normal. Additional imaging revealed lung and salivary glands involvement.

Results and treatment: The patient was commenced on Prednisolone 60 mg daily, reduced gradually to 7.5 mg daily maintenance dose. Significant symptomatic relief, resolution of cutaneous lesions and normalisation of ACE levels were noted. Repeat imaging of the hypothalamic/pituitary region is due in April 2018, to assess for regression of neurosarcoidosis and determine whether further steroid therapy is required as monotherapy or combined with second-line immunosuppressant agents.

Conclusions and points for discussion: Hypothalamic/pituitary sarcoidosis is a rare manifestation of sarcoidosis and usually presents with symptoms of hypogonadotrophic hypogonadism or diabetes insipidus. Endocrine symptoms may precede other multi-systemic symptoms and therefore sarcoidosis should be considered when investigating patients for hypothalamic/pituitary dysfunction, so that appropriate treatment can be commenced early.