Rosai-Dorfman disease involving the premaxilla.

Sinus histiocytosis with massive lymphadenopathy (SHML), introduced in 1969 by Rosai and Dorfman, is a benign and self-limited (albeit often relapsing) pseudolymphomatous entity with characteristic histopathologic features. Although the presence of massive cervical lymphadenopathy often aids in the diagnosis of SHML, the disease may present in the absence of detectable nodal involvement (Rosai-Dorfman disease). Therefore, the physician must be aware of such extranodal presentations. A recent review of the 365 cases in the SHML registry has revealed a preponderance of eyelid and/or orbital involvement; only 26 cases were found with subcutaneous or soft tissue involvement in areas other than the eyelid and/or orbit. This is a case report of one such atypical presentation of SHML without clinically apparent lymphadenopathy or eyelid or orbital involvement.