The clinical and histologic materials, including autopsy findings, from 6 cases with clinical features of so-called lethal midline granuloma were examined. These cases were selected by characteristic biopsy findings observed in the nasal lesions. The histologic features of the nasal lesions were necrosis and infiltration of atypical histiocytic cells. The mean age was 37 years with a 2:1 male to female preponderance. Nasal complaints and fever were frequent manifestation, and physical findings showed necrotic, granulomatous lesions in the nasal cavity in all cases. The survival ranged from 4 to 24 months, giving a mean value of 13 months. Autopsy findings revealed systemic, neoplastic proliferation of atypical histiocytes, from these observation, these 6 cases should be regarded as malignant histiocytosis (MH) with usual presentation.