Neurofibromatosis type 1 associated with pheochromocytoma: a case report with a brief review of the literature

Abstract

We presented the clinical case of neurofibromatosis type 1 (NF-1) associated with pheochromocytoma (PHEO) in a man under 40 years old without family history. The diagnosis of NF-1 was established based on 4 signs of the disease (multiple café au lait macules, scoliotic changes in posture, the presence of multiple neurofibromas, Lisch nodules). The diagnosis of PHEO was determined by a significant increase of free metanephrin/normethanephrin levels in daily urine, a malignant CT phenotype of the right adrenal tumor, and confirmed by pathomorphological study. Genetic tests revealed a new mutation in one of the alleles of NF1 gene, a deletion of a 566 bp gene fragment, including exon 19 with a size of 73 bp. This mutation leads to splicing of exons 18 and 20, frameshift, and termination of protein synthesis. A study of the level of transcription of the genes associated with PHEO (RET, TMEM127, MAX, FGFR, MET, MERTK, BRAF, NGFR, Pi3, AKT, MTOR, KRAS, MAPK) was conducted, a statistically significant decrease in the level of transcription of the KRAS and BRAF genes and increase in the level of transcription of the TMEM127 gene in comparison with control samples have been detected. This case demonstrates the need for timely recognition of NF-1 for further appropriate patient’s follow up and show the effectiveness of a multidisciplinary approach to the diagnosis and treatment of NF-1-associated catecholamine-secreting tumors.