[Solitary reticulohistiocytic granuloma--a report of three cases and a review of literature].

Case 1 was a 20-year-old male with a nodule on the scrotum. Case 2 was a 14-year-old female with a dome-shaped, reddish-brown nodule on the nose. Case 3 was a 30-year-old male with a dome-shaped, reddish-brown nodule on the forearm. All of the excised specimens showed typical features of solitary reticulohistiocytic granuloma. There were histiocytes and multi-nucleated giant cells in the dermal tumorous nests. They were stained positively with PAS reaction and anti-lysozyme antibody, but were stained negatively with S-100 protein antibody. To clarify the nosology of the reticulohistiocytic granuloma, we reviewed the literatures of multicentric reticulohistiocytosis and adult xanthogranuloma. Multicentric reticulohistiocytosis was considered to be a systemic disease and different from solitary reticulohistiocytic granuloma. However, adult xanthogranuloma showed clinical similarities to solitary reticulohistiocytic granuloma instead of the differences in the histopathologic features.