Endocrine Abstracts

Silent corticotroph pituitary neuroendocrine tumours (PiTNETs) are a subtype of nonfunctioning PiTNETs, that present positive immunostaining for adrenocorticotropin (ACTH) and/or show the expression of the transcription factor T-PIT without clinical signs of hypercortisolemia. They constitute 20% of all corticotroph PitNETs and manifest in most cases as macroadenoma with suprasellar extension and a higher tendency to apoplexy. We present a 33-year-old male with aggressive course of silent corticotroph PitNET. The patient was admitted to Emergency Department due to severe headaches and vomiting. Headaches (8-9/10 using numbering rating score (NRS)) and worsening vision loss were present one year before the surgery. In computer tomography, a sellar tumour mass (39x33x55 mm) was found with extrasellar extension, causing pressure on the cerebral aqueduct of the third ventricle, involving left sphenoid sinus. Additionally, features of cerebral edema were described. The patient was transferred to Neurosurgery Department and, external ventricular drainage was performed due to obstructive hydrocephalus. Two days later, debulking transsphenoidal surgery (TSS) was performed. Histopathology results showed silent adenoma subtype 1 (densely granulated), Ki67<1%. Genetic testing was negative for AIPand MEN1mutations. However, 3 months later, magnetic resonance imaging (MRI) showed progression of PitNET (40x39x30 mm) with increasing hydrocephalus. Subsequently, second TSS was performed, complicated with cerebrospinal fluid leak. Biochemically, persistent multiple pituitary hormone deficiencies and diabetes insipidus were diagnosed. Clinically, severe headaches (9-10/10 using NRS) without improvement after analgesic and worsening vision loss were observed. The patient was consulted by multidisciplinary pituitary tumour board and radiotherapy was planned. Pasireotide (10 mg) monthly and 0.5 mg of cabergoline weekly were scheduled, however, due to rapid progression of the tumour and the compression of optic chiasm, emergency TSS (05.2021) with the decompression of the optic nerves was performed. After surgery, chemotherapy with temozolomide (starting dose of 150 mg/m²) for 5 days was introduced. After first cycles, adjuvant stereotactic fractionated radiotherapy (total dose 50.4 Gy in 28 cycles) was performed. Temozolomide at the dose of 200 mg/m² for 5 days every 4 weeks was continued. Severe headaches (9-10/10 using NRS) without improvement after analgesic were still present. Pasireotide (increasing dose from 10 to 40 mg/month) was reimplemented, decrease of headaches from (initially 9-10 to none /10 using NRS) has been observed. In last MRI, after 5 cycles of temozolomide, and during pasireotide and cabergoline treatment, regression of the pituitary tumour (current measurements: 20x30x29 mm) was observed. Additionally, patients is in a very good general condition, reports no headaches.