Eighty-three cutaneous mast cell tumors in the dog were classified morphologically into three grades. The neoplasms were excised surgically, and the dogs were followed for 1500 days. Comparison of morphologic grade of tumor with survival time revealed significant differences among the three groups (p less than 0.00010). Comparison of sex and age (above and below ten years) with morphologic grade of tumor revealed no significant differences.

One hundred seventy-six canine lymphomas were classified morphologically using four of the major human lymphoma classification schemes (Rappaport, Lukes-Collins, Kiel, and the Working Formulation). All 176 dogs received the same chemotherapeutic protocol. Sixty-two of these lymphomas had their immunophenotypes established by examination of cell surface markers by automated cytofluorography. Several different morphologic types of canine lymphoma were identified and these were comparable to morphologic categories in human classification schemes. Follicular and low grade lymphomas were rare. The two most common morphologic types were diffuse large cell (centroblastic) and immunoblastic. The Kiel classification appeared to be the most useful human scheme for classifying the canine lymphomas. Cytofluorographic analysis was generally straightforward, and 60 of the 62 lymphomas were placed into one of three immunophenotypic categories: 27 pan-T(LQ1)+SIg+, 21 pan-T(LQ1)-SIg+, and 12 pan-T(LQ1)+SIg-. Two of the lymphomas could not be characterized immunologically because a pre-existing or reactive non-neoplastic population of lymphocytes made interpretation of single cell suspension analysis difficult. The authors identified correlations between morphology and survival and disease-free remission; dogs with high-grade tumors generally survived the longest and had the longest remissions. No correlations were identified between high concentrations of serum lactate dehydrogenase, age, sex, or stage of disease, and morphology, immunophenotype, remission, or survival times. A significant correlation between clinical illness and survival time was documented. The median age of the dogs was nine years, no significant effect of sex on prevalence was observed, and some breeds were significantly overrepresented. Significant morphologic-immunophenotypic correlations included shorter remission and survival times for T-cell tumors than B-cell tumors, and a highly significant correlation between the pan-T(LQ1)+SIg-"T cell" phenotype and hypercalcemia.

Abstract. Canine extraskeletal osteosarcomas are extremely rare tumors. Over a period of 25 years at the Animal Medical Center, approximately 1,000 cases of skeletal osteosarcomas have been diagnosed. During the same period 1 1 cases of extraskeletal osteosarcomas and three extraskeletal chondrosarcomas were diagnosed. Tumors of the mammary gland were excluded. Extraskeletal osteosarcomas were found in the adrenal gland, eye, gastric ligament, ileum, kidney, liver, spleen, testicle, and vagina. The chondrosarcomas were found in the mitral valves, lungs, and omentum. The mean age of the dogs with extraskeletal osteosarcoma was 11 years, and the mean age of the dogs with extraskeletal chondrosarcoma was 14 years. The sizes of the tumors ranged from 3 cubic centimeters to 8,3 15 cubic centimeters. Osteoblastic osteosarcomas were the most common histologic type (7/11, 63.6%); there was a single case of each of the following: fibroblastic, fibrous histiocytic, chondroblastic, and mixed osteo-chondroblastic osteosarcoma. Two of the dogs with chondrosarcomas had mesenchymal chondrosarcomas involving the lungs and omentum. The remaining dog had a regular chondrosarcoma involving the mitral valve. Distant metastases were present in seven of 11 dogs with extraskeletal osteosarcoma and in none of the dogs with chondrosarcoma. In contrast to human beings, in which most extraskeletal osteosarcomas occur in the soft tissues and the extremities, most canine extraskeletal osteosarcomas develop in the visceral organs.