Extranodal Rosai-Dorfman Disease with Cutaneous and Periodontal Involvement: A Rare Presentation

Sinus histiocytosis with massive lymphadenopathy (SHML) or Rosai-Dorfman disease (RDD) was first described as a distinct clinicopathological entity by Rosai and Dorfman in 1969. SHML is commonly characterized by painless cervical lymphadenopathy, and its clinical course is generally benign and self-limiting. This disorder commonly involves the lymph nodes but may secondarily involve the skin. However, purely cutaneous disease without lymphadenopathy or internal organ involvement rarely occurs. In the absence of the massive lymphadenopathy that is characteristic of RDD, the diagnosis of purely cutaneous RDD may be complicated by the rare, nonspecific clinical appearance of skin lesions and the broad histopathological differential diagnosis of this disorder. A high level of suspicion of this disease on the part of the clinician or pathologist is often required. We present a case of cutaneous RDD associated with involvement of periodontal tissue.