Case report on the effectiveness of combination therapy in highly aggressive resistant prolactinoma

#4301

Introduction: Prolactinomas represent 50% of pituitary neuroendocrine tumours (PitNET), aggressive prolactinomas represent 15% of them.

Aim(s): We aim to illustrate several therapeutic strategies when handling with resistant PitNETS.

Materials and methods: A 42-year-old male presented with headache in 2016. MRI showed a pituitary macroadenoma 3.5x3.8x4.0 cm, prolactin (PRL) level 200,000 mIU/L. We administrated cabergoline in titration, PRL level decreased to 15,098 mIU/L. In 2022 MRI showed adenoma size increased to 3.7x2.6x3.8 cm, PRL was 235,458 mIU/L and we escalated cabergoline dosage to 4.5 mg per week. In 2023 PRL was 108,700 mIU/L. MRI revealed a negative dynamic. We added to the therapy a tamoxifen 20 mg daily. Due to the absence of the remission a transcarinal resection of a pituitary adenoma was performed, histological analysis confirmed a heightened mitotic activity. PRL was 102,279 mU/L. A transnasal transsphenoidal resection was performed in 6 months. Ki-67 12% in hot spots. MRI showed a residual tumour tissue on the left side 3.5x3.1x2.1 cm and on the right side 2.1x1.6x1.2 cm. The patient underwent a radiation therapy of 54 Gy. By 2024 PRL was >70,000 mU/L, subsequent MRIs showed no significant changes. Repeated IHC analysis for receptor expression revealed VEGF expression in 80% of cells, no oestrogen receptors. Tamoxifen was discontinued. We recommended bevacizumab and temozolomide, the patient is currently under observation.

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Authors: Asanova A, Shutova A, Pigarova E, Dzeranova L,

Keywords: prolactinoma, IHC, Pit Net, chemotherapy,