Endocrine Abstracts

Introduction: Aggressive pituitary tumours are rare (<2% of pituitary macroadenomas) and are characterized by local invasiveness, progressive growth, and multiple recurrences despite conventional treatments. Approximately 30-40% of these tumours are functioning corticotroph adenomas. Diagnosis relies on clinical, imaging evaluation with magnetic resonance imaging (MRI), hormonal, and pathological assessments. Its therapeutic approach is challenging.

Clinical Case: A 53-year-old woman diagnosed in 2015 with Cushing’s disease due to a pituitary macroadenoma underwent transsphenoidal resection, with no apparent residual lesion and normalization of ACTH levels. Histology identified a corticotroph pituitary adenoma with a low Ki67 (<3%) and p53+ in more than 50% of cells. One year later, she experienced a significant tumour recurrence, leading to a second surgical intervention where complete tumour resection was impossible. Therapy with cabergoline and gamma-knife radiosurgery was conducted, resulting in residual tumour. Elevated ACTH levels and hypercortisolism persisted, and therefore metyrapone was initiated. The clinical picture of hypercortisolism worsened, leading to the development of diabetes mellitus, vertebral osteoporotic fractures, and retinal detachment. In 2020, she underwent bilateral adrenalectomy. Since then, there has been a gradual rise in ACTH levels with persistent lesions. In 2023, she experienced a sudden episode of ophthalmoplegia and left eyelid ptosis, consistent with homolateral cavernous sinus syndrome. MRI confirmed left cavernous sinus invasion by the pituitary tumour, prompting urgent transsphenoidal surgery with subtotal lesion resection. Histology revealed a corticotroph pituitary tumour with Ki67 15% and an increased number of mitoses. Postoperative imaging control showed residual intra-sellar lesion with bilateral cavernous sinus involvement. Genetic testing (FoundationOne) did not identify any mutation considered a therapeutic target. Following multidisciplinary discussion, chemotherapy with temozolomide was initiated (administered every 3 weeks, with a dose of 150mg/m² in the first cycle and 200 mg/m² in the following). The treatment was well-tolerated, without hematological complications. An initial reduction in ACTH levels was observed, as well as lesion stability at the end of the 6th cycle.

Conclusion: This case presents an aggressive corticotroph adenoma, illustrating the complexity of its treatment, which requires a multimodal and multidisciplinary approach. Due to tumour progression despite various interventions, temozolomide therapy was initiated.