[Crow-Fukase syndrome].

In Japan, Crow-Fukase syndrome is a target of active research because of many cases reported. Therefore, the following three topics regarding this syndrome were discussed. 1) Etiology of Crow-Fukase syndrome. Even in reported cases of Crow-Fukase syndrome with monoclonal protein or polyclonal immunoglobulins and no apparent multiple myeloma, there were plasmacytomas in the lymph node or other tissues, and symptoms became improved after removal of these tumors. Therefore, plasma cells seem to be involved. According to recent studies, impairment of the pituitary function may play some role. 2) New pathological findings in the lymph node histology. In the lymph node of patients with this syndrome, we found in its germinal center a peculiar abnormality called angiosclerosis, in which branching tortuous capillaries with thickened wall including many cells were prominent, which may be different from those of Castleman's disease. 3) Nerve conduction studies using a new collision technique. Crow-Fukase syndrome is associated with marked slowing of even the maximal motor and sensory conduction velocities. Therefore, in order to understand its pathophysiology better, submaximal conduction velocities should be measured using the new collision technique because this technique is different from Hopf's method that is affected by the refractory period of nerve fibers.