Multicentric reticulohistiocytosis, like sarcoidosis, lupus erythematosus, scleroderma, and mastocytosis, is a dermatologic disease with serious internal organ involvement. Dermatologists have played a leading role in the development of knowledge of the systemic manifestations of this disease. Continuing the process of delineation, Orkin and his co-workers in this issue of the Archives report the results of their exhaustive studies of a recent patient having this interesting and important illness.
There have now been reported 23 cases of multicentric reticulohistiocytosis. It is noteworthy that 13 of these patients lived in the United States, 6 in Great Britain. Four of the 23 have been studied at one institution, the University of Minnesota, 2 at the nearby Mayo Clinic, and 3 in Chicago. It is probable that this seeming concentration of patients in a relatively limited geographic area reflects only a high index of awareness of this disease in that region, rather than any