Histologic classification as an indication of therapeutic response in malignant lymphoma of dogs.

In retrospective evaluation of treatment of canine malignant lymphoma, 12 of 13 dogs that had received doxorubicin alone or in combination with dacarbazine attained complete remission. Doxorubicin had been given alone, with combination chemotherapy being used only when complete remission could not be achieved and maintained with doxorubicin. The response to single or combined chemotherapy was correlated with histologic cell type of the malignant lymphoma. Histiocytic cell types did not respond to doxorubicin alone, but lymphoblastic types did respond. Combination chemotherapy was effective against histiocytic types. A mixed-cell type, which was initially responsive to doxorubicin alone, but not responsive after relapse, was observed to be histiocytic on rebiopsy.