Case Report: Silent Corticotroph Adenoma Progressing to Cushing's Disease then to Pituitary Carcinoma with Dramatic Treatment Response

Objective: Pituitary carcinomas are rare neuroendocrine tumors with local parasellar invasion and distant metastasis requiring a multimodality approach.

Design: Herein we report a case of a 54-year-old man diagnosed with a silent corticotroph adenoma who developed Cushing's disease that progressed to pituitary carcinoma.

Patients/Methods and Results: In 1998, the patient had a sinusitis evaluation, revealing a sellar mass with elevated ACTH levels. By 2004, he developed Cushing's disease with elevated 24-hour UFC and ACTH level of 300 pg/mL. He had transsphenoidal subtotal removal of an invasive adenoma. After a steady increase in ACTH, cortisol levels, and tumor growth, he had repeat transsphenoidal surgery. In July 2010 with tumor growth and worsening effects of hypercortisolemia, he had endonasal endoscopic tumor debulking. He began temozolomide therapy; however, his condition deteriorated—with tumor growth in the sella, clivus, left cavernous sinus, and left middle fossa. He then had two-stage tumor debulking with a left transcranial approach and a redo endonasal endoscopic approach. Pathology marked tumor progression with Ki-67 from 80%–90%. Whole body PET-CT showed a liver lesion, confirming ACTH-staining pituitary carcinoma when biopsied. He began treatment with cisplatin and etoposide. His most recent brain/pituitary MRI in 2012 shows almost complete resolution of the residual skull base and left middle fossa mass; his ACTH levels fell to <15 pg/mL, and his serum cortisol was <2 üg/dL.

Conclusion: As far as we know, this is the first reported case with dramatic response to combined cisplatin and etoposide therapy for pituitary carcinoma.