2026 Poster Presentations
P202: METPITNETS DEVELOPMENT AFTER ADENOMA RESECTION AND SUBSEQUENT SRS : A REVIEW FROM LITERATURE
Jan Hemza, MD, PhD, PhD, MPA1; M Nosal, MD1; V Feitova, MD2; M Hermanova, Prof, MD3; 1Dpt. of Neurosurgery, Faculty Hospital at saint Ann; 2Dpt. of Imaging Methods; 3Institute of Pathology
MetPItNETs (Metastatic Pituitary Neuroendocrine Tumor) are extremly rare pituitary tumor. MetPitNETs - pituitary carcinoma can present at any age typically presents in the third to fith decade of life in patients with preexisting pituitary adenoma. 207 patients with primary diagnosis of MetPitNETs described in the literature up to 2023, drawn from 128 full texts and 138 in PDF, in the last year full text views 19, PDF 28.
In WHO 2022 clasification adopted the term Pituitary Neuroendocrine Tumor (PitNET). The first group pituitary hormon-secreting cells the clinical behavior of some pituitary tumors „ adenomas“ referred to as very benign tumors. And 2nd group MetPitNET – Metastatic Pituitary Neuroendocrine Tumor – call before carcinoma.
Incidency of PitNETs acounting approximately 10-20% of all intracranial neoplasms although the vast majority >90% are benign, a small percetage < 2% are aggressive PitNETs (AgPitNETs), pituitary carcinomas -metastatic PitNETs (MetPitNETs) only 0.2% of case.
Medical history and physical exam: Patient, 61 years old, XII/2007 primary dg.: Pituitary macroadenoma, afunctional, operation I/2008 – subtotal resection. Histology. pituitary adenoma M8272/0, mitotic figures are found quite sporadically. VI/2009 – MRI residue, followed by stereotactic radiosurgery (SRS) of the residue (Leksell gamma knife) IX/2009. Further MRI follow-up 2008-2014 every 1y., 2014-2020 á 2yy., (II and XII/2020) and 2023 and 2025. MRI 2023 – macroadenoma residue in a lighter progression of about 3mm in sagittal projection compared to above 2020. After MRI complete craniospinal 2025 with the finding of multiple spread of tumors in the area of the meninges in the posterior cranial fossa, and the upper cervical spine the surgery with histological diagnosis was indicated – diff. dg. meninigomatosis after irradiation or other pathology. Histology : MetPitNET M8272/3, Ki-67 2%diffusely, mitotic activity 1 mitose/10HPF, Immunophenotype neoplasia: synptophysin +, chromogranin +, SSTR2A + Intensive nuclear accumulation of p53 immunohistochemically demonstrated in a significant number of tumor cells, approximately 2% (p53 wildtype).
Discusion: Therefore, reported latency periods of natural develope MetPitNETs vary from 4 month to 18yr, with a mean interval of 6,6yr..
After SRS treatment 5-, 10-, and 15-year risk of malignant transformation was 0.5% (95% CI, 0.0%-0.9%), 0.8% (95% CI, 0.0%-1.8%), and 2.4% (95% CI, 0.0%-5.5%), respectively.
The interval from the initial diagnosis of PitNETs to the transformation ranged from 1 to 20 years, with an average of 6.25 ?} 4.19 years. The transformation often occurred following recurrence of the tumor after surgery. The treatments or events before the transformation were surgery (88.9%), radiotherapy (33.3%) or pituitary apoplexies with clinical symptoms (7.4%), which might promote the transformation of PitNETs as in some malignant tumors.
Conclusion: From the literature, this is probably the first malignant transformation of non-functional adenoma treated in combination surgery and subsequently SRS residues in 1 year.
Malignant transformation occurred after 18 years, of which the average natural transformation is 6.6 years and mailing transformation after SRS increases from 5 to 15 years (0.5%, 0.8%, 2.4%).
Literature: 14