Endocrine Abstracts

Xanthoma Disseminatum: A rare cause of hypopituitarism

S Ray and PE Belchetz; The General Infirmary at Leeds, Leeds, UK.

Xanthoma disseminatum (XD) is a rare, benign, normo-lipaemic condition characterised by non- Langerhan's cell histiocytosis which usually effects male children or young adults. Patients develop nodular or infiltrating papules that are distributed along flexural areas and mucosal surfaces. Meningeal infiltration causes diabetes insipidus (DI) in upto 40 % of patients and seizures. Anterior pituitary dysfunction is extremely rare.

Our patient presented, aged 5 yrs, with dark lesions on his face and chest. Skin biopsy showed features of XD. Aged 12 years he developed DI and subsequently anterior pituitary dysfunction requiring treatment with thyroxine, hydrocortisone, genotropin and desmospray. Computerised tomography (CT)of the brain revealed characteristic thickening of the pituitary stalk. 2 years later he had an episode of temporal lobe seizure needing carbamazepine therapy.

Various treatment regimen including etoposide, topical nitrogen mustard and thalidomide were tried for his skin lesions with little effect. Disfiguring xanthomata on his eyelids, sclera and cornea seriously affected his vision. Laryngeal involvement causing chronic stridor and dyspnoea required a tracheostomy.

Over the years the skin lesions showed minimal regression. Following recent treatment with cyclophosphamide, the xanthomata have shown good response. Surgical intervention has improved vision in his right eye and his tracheostomy is due to be reversed in the near future. Pituitary function remains stable on replacement therapy.

Treatment options in XD are limited. Most present to dermatologists with xanthomata which tend to regress with time. Some show minimal radiosensitivity while others respond to azothiaprine or cyclophosphomide. Pituitary dysfunction persists lifelong. Supportive treatment and specialist follow-up is recommended.