Pathology of cat-scratch disease.

A pathologic and histogenetic study of material obtained from ten cases of cat-scratch disease was carried out. The earliest lesion was of ten days' duration and the oldest of 35 days' duration. The first changes in lymph nodes consisted of proliferation of epithelioid cells followed by exudation of leukocytes in their centers and subsequent necrosis of the exudate and epithelioid cells. Proliferative changes leading to formation of epithelioid cell tubercles were seen in some cases. Homogenization of necrotic centers brought about the formation of caseous tubercles similar to those seen in tuberculosis, syphilis, lymphogranuloma venereum and tularemia. Differentiation and the final diagnosis of cat-scratch disease rests upon correlation of histopathologic observations, clinical studies and specific skin tests.