Dirofilaria infection in the breast of a woman in Japan.

Dirofilaria infection in the breast of a woman was reported from Japan. A nodule in the breast was excised and histologically examined. The sections of a female nematode were found in the center of the nodule. Based on the morphological features of this worm, it is suggested that this may represent the second human case of Dirofilaria immitis occurring in the breast.