Rosai-Dorfman Disease with Massive Cutaneous Nodule on the Shoulder and Back

Abstract

Rosai-Dorfman disease is a rare, idiopathic, benign, andself-limiting histiocytic proliferative disorder. A 26-year-oldman presented with a single massive cutaneous nodule(reaching 30 cm in diameter) on the left shoulder and back for15 months. The routine hematological and biochemical testswere normal. Magnetic resonance scanning showed the lesioninvolved the skin, subcutaneous tissue, and subjacent musclegroup, accompanied by obvious lymph node enlargement inthe left part of the neck, supraclavicular fossa, and axillaryfossa. The histopathology of the left cervical lymph noderevealed diffuse effacement of the normal nodal architecture,with patchy chronic inflammatory cell infiltrates comprisinglymphocytes and sheets of histiocytes. Some histiocytescontained lymphocytes within their pale cytoplasm. Manymultinucleated giant cells were found; however, caseatinggranulomas were not seen. The skin and muscle biopsyspecimen obtained from the back revealed infiltratinglymphocytes and histiocytes diffusely distributed in thedermis, subcutaneous tissue, and crevices of the muscle fibers. The phenomenon of emperipolesis and the presence ofmultinucleated giant cells were also seen. Immunohistochemicalstaining revealed that the histiocytes were positivefor S-100 protein and CD68 but negative for CD1a. Immunophenotyping of the infiltrating lymphocytes indicatedpositive reactions to CD3, CD45RO, CD5, CD7, CD4, CD8(partly), CD79a, CD20 (partly), and Ki-67 (＜1%). The finaldiagnosis was Rosai-Dorfman disease. Owing to the extensiveand deep involvement of the subcutaneous tissue and muscles,the patient did not undergo surgery to excise the massive skinnodule. The lesion showed no obvious change at the 12-monthfollow-up.