Estudo Clinicopatológico, imuno-histoquímico e molecular do xantogranuloma juvenil oral

Abstract

Juvenile xanthogranuloma (JXG) is the most common form of non-Langerhans cell histiocytosis in childhood. Although cutaneous lesions are common, oral mucosa involvement is exceedingly rare. Some studies investigated the genetic basis of cutaneous and extracutaneous JXG, however, no data is available for oral JXG. Histiocytic disorders have been associated with activating MAPK pathway mutations, including the report of BRAF V600E in JXG extracutaneous sites. Herein the clinicopathological and immunohistochemical features of five new cases of oral JXG were evaluated in conjunction with a literature review. Also, we assessed the BRAF V600E mutation in oral samples. Five oral JXG were retrieved from two oral pathology services in Brazil. Clinical and demographic data were collected from medical records. Clinicopathological and immunohistochemical analyses were performed. The BRAF V600E status was determined with TaqMan allele-specific qPCR. The series comprised of2 men (40.0%) and 3 women (60.0%), with a mean age of 38.8 ± 22.9 years (range: 13–68 years) and a 1.5:1 female-to-male ratio. The buccal mucosa (n = 3, 40.0%) was the most common location. Clinically, lesions appeared as a normochromic or yellowish asymptomatic nodules measuring from 1.0 to 2.5 cm (1.7 ± 0.6). No cases presented cutaneous lesions. All cases were surgically excised. Morphologically, most cases (n = 4, 80.0%) presented classical histological features of JXG with histiocytic cells positive for CD68, CD163, and factor XIIIa. Considering the BRAF status, BRAF V600E was not detected in the cases tested. This is the first and largest series published affecting adults and a Brazilian population. Molecular pathogenesis of oral JXG remains unknown