The patient was a 76-year-old female who had been referred to our hospital because of fever of unknown origin on October 15, 1987. On admission, the body temperature was 38.6 degrees C and atonic palsy of the left upper limb was noted. Abnormal laboratory findings included CRP5+, an increase in LDH, Hb 7.9 g/dl. The cause of the fever could not be identified. The fever did not respond to various treatment. The patient developed DIC in late October and died on November 5. In autopsy histological examination revealed tumor cells in the vessels of the generalized organs. A diagnosis of neoplastic angioendotheliosis (NAE) and immunohistologically B lymphoma was made. We reviewed the literature on 37 Japanese cases of NAE. The cases, consisting of 19 males and 18 females, were aged 37-87 years with a median value of 60 years. The symptoms observed during the course were most frequently mental or neurological symptoms and fever, and rash was uncommon. Laboratory findings were non-specific and biopsy was needed for definitive diagnosis. By autopsy, lesions were noted more frequently in the brain, kidneys, and lungs, and the findings in the skin were indeterminate. These observations suggest that when NAE should be considered, kidney, lung or skin biopsy should be performed for definitive diagnosis.