Graves' disease (GD), myasthenia gravis (MG), and polymyositis (PM) ar
e organ-specific autoimmune diseases. The association between GD and M
G is well known, and an association between MG and PM has been reporte
d. However, only one patient with all three diseases has been reported
. We describe a patient with GD and PM developing 6 and 29 years, resp
ectively after the onset of MG. This case suggests that the expression
of autoimmunity occurred over a prolonged period of time and these or
gan-specific autoimmune diseases may be induced by a similar mechanism
.