[Pituitary atypical adenoma or malignant corticotrophinoma?]

Pituitary tumors are classified into typical adenomas, atypical adenomas or carcinomas. Carcinoma represents 0.2% of pituitary tumors and is defined by the presence of metastases. It often presents as invasive and secreting macroadenoma, showing features of malignancy ab initio or over time. The high proliferative index (Ki-67) and immunostaining for p53 protein are common indicators of aggressiveness. We report a 58 years old male with invasive sellar incidentaloma. The hormonal study showed gonadal, thyroid, and somatotrophic failure, with increase of corticotropin (ACTH) and cortisol. Transsphenoidal surgery was performed and histology revealed a typical corticotrophinoma. The successive recurrences over 10 years led to five surgical reoperation and radiotherapy. After the third surgery, cellular atypia, Ki-67 of 27% and immunostaining for p53 were revealed. Subsequently, there were lesions suspicious of metastases (lung and lymph nodes), but the biopsy of the lymph nodes was inconclusive. The patient died before chemotherapy. In this case, the progressive loss of differentiation points to the need for early diagnosis, timely and aggressive treatment.