Introduction: Crooke’s corticotropinomas are the unique cause of Cushing’s disease. The majority of them are aggressive macroadenomas, refractory to conventional therapy, with a high recurrence rate. The aim of the study was the presentation, in relation to data from the literature, of a case of a patient with ACTH-dependent Cushing’s syndrome caused by recurrent Crooke’s cells corticotropinoma, who achieved 33-month complete remission after treatment with temozolomide (TMZ).

Case report: A 54-year-old man was diagnosed with Cushing’s disease five years earlier on the basis of a typical clinical picture and hormonal tests. MRI revealed 32 × 29 × 24 mm macroadenoma. The patient underwent three subtotal selective transsphenoidal adenomectomies without retirement of hypercortisolaemia. A postoperative pathologic exploration revealed a densely granulated corticotroph Crooke’s cells adenoma with MIB-1 index < 1%. Because of the large size of the tumour with its expansion to both cavernous sinuses and suprasellar region together with a compression of the optic chiasm, the patient was disqualified for gamma–knife. Due to an exhaustion of all conventional therapeutic options the patient was qualified to TMZ therapy. The standard dose of TMZ (150 g/m²) for five days every 28 days was implemented. After three courses of TMZ pronounced regression of tumour size with a marked hormonal and clinical improvement was certified. After six courses, consecutive tumour regression was observed. Nine courses resulted in a total radiological tumour shrinkage and hormonal normalisation. Despite the cassation of TMZ treatment the complete remission of the disease maintained for 33 months.

Conclusion. Temozolomide can be an effective treatment option in invasive Crooke’s cell corticotropinoma. (Endokrynol Pol 2016; 67 (5): 526–533)