Oral Juvenile Xanthogranuloma: A Clinicopathological, Immunohistochemical and BRAF V600E Study of Five New Cases, with Literature Review.

Juvenile xanthogranuloma (JXG) is the most common form of non-Langerhans cell histiocytosis and oral mucosal involvement is exceedingly rare. Histiocytic disorders harbor activating mutations in MAPK pathway, including the report of BRAF V600E in JXG of extracutaneous site. However, no information is available for oral JXG. Herein, the clinicopathological and immunohistochemical features of five new oral JXG were evaluated in conjunction with literature review. Also, we assessed the BRAF V600E in oral samples. Five oral JXG were retrieved from pathology archives. Morphological and immunohistochemical analyses were performed. The BRAF V600E status was determined with TaqMan allele-specific qPCR. The series comprised of three female and two male patients, most of them adults, with a median age of 39 years (range 13-68 years). Clinically, the lesions appeared as asymptomatic solitary nodules, measuring until 2.5 cm, with more incident to the buccal mucosa. Morphologically, most of the cases presented classical histological features of JXG, with histiocytic cells consistent with the non-Langerhans cell immunophenotype. BRAF V600E was not detected in the cases tested. This is the first and largest published series of oral JXG affecting adults and a Brazilian population. The molecular pathogenesis of oral JXG remains unknown. Clinicians and pathologists must recognize JXG to avoid misdiagnoses with oral benign or malignant lesions.

Oral juvenile xanthogranuloma in a child: Clinical, histological and immunohistochemical profile of a rare entity.

Juvenile xanthogranuloma (JXG) is a non-Langerhans cell histiocytosis (non-LCH) affecting normolipemic infants and children most frequently in the first year of life, often showing spontaneous regression within 3 to 6 years. Classic JXG is characterized by a yellowish asymptomatic papule or nodule, often located in the skin of the head, neck and upper trunk. Oral JXG has been reported, but is rare. Histologically, JXG is composed mainly of an infiltrate of macrophages with a variable degree of lipidization (foamy macrophages), and (most of the time) scattered Touton-type giant cells. Because of the rarity of oral lesions and possible variations in the clinical and histological presentation, the correct diagnosis can be challenging, requiring a careful clinical and histopathological evaluation with adjuvant immunohistochemical studies. Our review of the English-language literature disclosed 33 cases of oral JXG, including this case report. The purpose of this study is to present a new case of this uncommon entity as well as to review and discuss its main clinicopathologic features and immunohistochemical findings.

Gingival juvenile xanthogranuloma in an adult patient: case report with immunohistochemical analysis and literature review.

Juvenile xanthogranuloma (JXG) is a non-Langerhans cell histiocytosis (nonLCH). It is a benign and self-healing disorder that generally affects infants and children. Oral lesions in adult patients are rare, although the microscopic findings are similar to those observed in other locations. A 56-year-old white man presented with a chief complaint of a gingival mass that had appeared 6 months before and had grown slowly. An intraoral examination revealed the presence of a solitary, softened gingival mass affecting the mandibular lingual gingiva at the right central incisor area. A biopsy of the lesion showed multiple large macrophages and numerous giant cells of Touton type. The immunohistochemistry positivity for CD68, fascin, factor XIIIa, alpha-antitrypsin and negativity for S-100, beta-actin, CD1a, and desmin confirmed the diagnosis of JXG. The occurrence of adult oral JXG is extremely rare. It is a nonLCH that may present variable clinical and microscopic aspects, which leads to a diversity of clinical misdiagnoses. A precise diagnosis of these lesions requires an accurate evaluation of clinical, microscopic, and immunohistochemical features.