Sinus and palatal Rosai-Dorfman Disease: Case report and review of the literature

Rosai-Dorfman Disease (RDD) is a rare non-Langerhans cell histiocytosis. We present a unique case of RDD with sinus and palatal involvement managed with surgical biopsy, debulking and radiation, and review the literature on this topic. A 69-year-old female presented with a two-year history of nasal obstruction and left-sided epiphora. CT imaging demonstrated a large soft tissue mass with extension into and bony destruction of the left maxillary sinus and hard palate. An initial biopsy obtained at an outside center reported an inflammatory myofibroblastic tumor. MRI and PET-CT were obtained and identified no additional lesions or lymphadenopathy. A repeat biopsy was performed in clinic but was non-diagnostic. The patient was taken to the operating room for biopsy and debulking of the sinonasal mass, and final pathology demonstrated proliferation of large histiocytic cells with clear cytoplasm and emperipolesis on a background of fibrosis. The tumor stained positive for S100, BCL1 and OCT2, consistent with RDD. The patient then underwent targeted radiation therapy. At 15-month follow-up, MRI showed no evidence of disease recurrence. While RDD is classically described as "sinus histiocytosis with massive lymphadenopathy", this case features extranodal sinus and palatal involvement with no lymphadenopathy. RDD is notoriously challenging to diagnose, and we highlight that our pathology is positive for OCT2, which has recently been found to be a novel and specific marker associated with the monocyte-macrophage phenotype of RDD. We demonstrate that symptomatic extranodal sinus and palatal RDD can be diagnosed and treated with a combination of surgical biopsy, debulking and radiation.