Voluminous primary intraosseous xanthoma of the mandible in a 15-year-old girl: A clinical case followed over 3 years

The intraosseous xanthoma of the jaw (IOXJ) is a rare benign tumor made of lipid-laden histiocytes whose discovery is most often accidental in young normolipidic people. To this day, there is less than 50 cases reported in the English literature. A 15-year-old female patient was referred for a left mandibular body lesion. A mandibular deformation and episodes of pain/numbness/paresthesia in the lower lip and chin area were described. X-ray imaging showed a wide radiolucent area of 61 mm × 26 mm involving the apices of 31 to 37 but lacked distinctive features to support a definitive diagnostic hypothesis. Although lesion’s biopsy of the lesion was inconclusive but suggested a benign nature. Conservative surgery with thorough curettage was performed. Final histopathological findings revealed macrophages filled with fat within their cytoplasm, referred to as xanthomatized cells; after exclusion of Langerhans cell histiocytosis or Erdheim-Chester disease, the diagnosis of IOXJ was established. The long-term prognosis revealed a satisfying healing without complications after a 3-year follow-up. Diagnosis of primary IOXJ is very difficult task: 1/ the intraosseous site is extremely rare, 2/ it is not associated with other xanthomatous locations (absence of lipid metabolic abnormalities), 3/ there is a wide variation in radiological presentation, 4/ despite the presence of xanthomatized cells, histological diagnosis is essentially based on exclusion.