Adult onset Still's disease (AOSD) is a systemic inflammatory disorder of unknown cause characterized by high fever accompanied by systemic manifestations. Since AOSD consists of heterogeneous symptoms and has no definite diagnostic tool, the diagnosis is based upon exclusive criteria. Dermatopathic lymphadenopathy (DL) is characterized by a localized paracortical proliferation of histiocytes and deposition of melanin in the lymph nodes. DL is not only a reactive hyperplasia of the lymph nodes, but has also been reported to be associated with hematological malignancies such as cutaneous T cell lymphoma (CTCL) and Hodgkin's lymphoma. It is therefore important to evaluate CTCL or Hodgkin's lymphoma in a patient with DL, in order to both rule out hematological malignancy and diagnose AOSD. In this report, we first describe a 37-year-old patient with AOSD whose biopsy of lymph node was proved to be DL.