Endocrine Abstracts

Introduction: The association between neurofibromatosis type 1 (NF-1) and neuroendocrine tumors, particularly pheochromocytoma (PC), has not been well characterized in our populations. NF-1 is a genetic disorder that presents with various clinical manifestations, and understanding its relationship with neuroendocrine tumors is essential for effective management.

Case presentation: We describe a clinical case of a 52-year-old man from Venezuela diagnosed with NF-1 in 2019. The diagnosis was based on the presence of four hallmark signs: café-au-lait skin lesions, scoliosis, multiple neurofibromas, and Lisch nodules. The diagnosis of pheochromocytoma was established through significantly elevated levels of free metanephrines and normetanephrines in a 24-hour urine collection, as well as the identification of a malignant phenotype in the right adrenal gland tumor via CT scan. This diagnosis was confirmed by pathomorphological examination. During genetic analysis, a novel mutation classified as of uncertain significance was identified in one of the NF1 gene alleles: a 482 bp deletion that included exons 16 and 22. This mutation caused splicing alterations, resulting in a reading frame shift and premature termination of protein synthesis. Additionally, a study of the transcription levels of genes associated with pheochromocytoma (RET, TMEM127, MAX, FGFR, MET, MERTK, BRAF, NGFR, PI3K, AKT, MTOR, KRAS, MAPK) revealed a significant decrease in KRAS and BRAF transcripts and an increase in TMEM127 transcripts, categorizing the pheochromocytoma in this case as associated with the second group of genetic abnormalities in paragangliomas.

Conclusion: This case underscores the importance of timely recognition of NF-1 and the need for a multidisciplinary approach to manage catecholamine-secreting tumors effectively. Early diagnosis is crucial for developing appropriate follow-up strategies for affected patients.