Rosai-Dorfman disease of the maxilla: A rare case report and literature review

Rosai-Dorfman disease (RDD) is a histiocytic proliferative disease characterized by painless bilateral cervical lymphadenopathy that often affects the extranodular sites, including the head and neck region. However, jawbone involvement in RDD is rare, with only 13 cases reported to date. We report a case of maxillary RDD in a 65-year-old woman with a history of surgical resection of a mesenteric gastrointestinal stromal tumor (GIST) 12 years previously. Subsequently, she was administered imatinib for the treatment of recurrent GIST. Positron emission tomography with computed tomography showed an increased accumulation of 18-F fluorodeoxyglucose on the left side of the maxilla and the colon fossa, both of which were clinically suspected to be metastases of an imatinib-resistant GIST. During intraoral inspection, an elastic soft mass was observed in the buccal gingiva of the left posterior maxilla. A definitive diagnosis was not obtained with the incisional biopsy specimen; therefore, an excisional biopsy was performed under general anesthesia. Histopathologically, the lesion consisted of a sheet-like aggregation of histiocytic cells accompanied by chronic inflammatory cells. Histiocytic cells showed inclusion of inflammatory cells (emperipolesis) and were immunohistochemically positive for both S-100 protein and CD68. Finally, the lesion was diagnosed as RDD. No evidence of RDD recurrence has been observed for more than 6 years in this patient. Excisional biopsy should be considered for RDD, especially when a partial biopsy sample is not large enough to make an accurate histopathological diagnosis.