Endocrine Abstracts

Nelson’s syndrome is a recognised complication of bilateral adrenalectomy for Cushing’s disease. The treatment of this condition can be extremely difficult. We report a case who failed to respond to traditional treatments, was given a novel chemotherapeutic agent temozolomide.

A 50 years old lady was diagnosed with pituitary dependent Cushing’s disease in 1998. She underwent transphenoidal hypophysectomy (TSS) twice, followed by conventional radiotherapy. In 2003, she had bilateral adrenalectomy, as combinedmedical treatments had failed to control her disease. She subsequently developed Nelson’s syndrome. She underwent craniotomy and debulking of the cavernous sinus mass with insertion of Gliadel wafers. However ACTH levels continued to rise and stereotactic surgery with Gamma knife was arranged in 2005. MRI in September 2006 showed expansion of the mass with doubling of ACTH levels. She underwent further TSS. Nevertheless ACTH levels continued to rise and she developed oculomotor nerve palsy. In March 2007 her ACTH levels rose to 24 450 from the initial level of 165 ng/l. She was then referred for chemotherapy.

Temozolomide was started orally at a dose of 150 mg/sqm². She has completed her 3rd cycle successfully so far. The ACTH levels dropped to 7133 ng/l.

The incidence of Nelson’s syndrome after bilateral adrenalectomy is estimated to range from 0 to 42%. Neurosurgical intervention and conventional radiotherapy may reduce or delay the subsequent occurrence of Nelson’s syndrome. Stereotactic radiosurgery might be more beneficial. The experience with neuropharmacological agents so far is very limited.

Temozolomide is a DNA-methylating agent of the imidazotetrazine class. It has been mainly used in Gliomas, Melanomas and metastatic brain tumours. Chemotherapy with Temozolomide has shown some benefits in Neuroendocrine tumours, but the role in Nelson’s syndrome is not known. The initial symptomatic and biochemical response of our patient is very encouraging.