Retrospective study of canine cutaneous tumors in Korea

Abstract

Over the 42 month period from January 2003 to June 2006, a total of 2,952 canine biopsy specimens were received from the Veterinary Medical Teaching Hospital of Seoul National University and from veterinary practitioners across the nation. Out of these, 748 (25.34%) cases were diagnosed as canine cutaneous tumors in the Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, Korea. Thirty-eight different types of cutaneous tumors were identified and categorized into epithelial and melanocytic tumors (56.95%), mesenchymal tumors (38.90%), and hematopoietic tumors (4.14%) located in the skin. Among these, 69.25% were benign and 30.74% were malignant. The top ten most frequently diagnosed cutaneous tumors were epidermal and follicular cysts (12.70%), lipoma (11.36%), mast cell tumors (8.82%), cutaneous histiocytoma (7.49%), basal cell tumors (6.82%), sebaceous gland adenoma (6.68%), sebaceous gland hyperplasia (5.08%), hepatoid gland adenoma (3.61%), apocrine adenocarcinoma (3.07%), and fibroma (2.81%), in order of prevalence. They comprised 68.45% of all cutaneous tumors. These top ten cutaneous tumors were distributed on the trunk (30.08%), head and neck (20.9%), extremities (19.14%), anal and perianal area (8.59%), and tail (3.91%). The age of the dogs with the ten most frequent tumors had a mean age of 8.3 years, with a range of 2 months to 19 years. When all types of tumors were considered together in the entire population, there was no difference in incidence according to sex.

Fig. 1

Photomicrographs of cutaneous and mesenchymal tumors of canine. (A) Basal cell tumor, medusoid subtype. Note neoplastic cells aggregated in the center and cords stream outward in medusa pattern. H&E stain. bar = 200 µm. (B) Epidermal cyst. Note a wall of squamous epithelial cells containing keratinous content in its lumen. H&E stain. bar = 200 µm. (C) Hepatoid gland adenoma. Note well differentiated hepatoid cells arranged in anastomosing trabeculae. The individual neoplastic cells resemble hepatocytes. H&E stain. bar = 100 µm. (D) Hemangiopericytoma. Note neoplastic cells demonstrate the perivascular whorled pattern and storiform pattern. H&E stain. bar = 100 µm. (E) Cutaneous histiocytoma. Note compact sheet of neoplastic histiocytes replacing adnexa and infiltrating into the epidermis. H&E stain. bar = 80 µm. (F) Mast cell tumor. Note a dense sheet of neoplastic mast cells causing collagenolysis. Aggregates of eosinophils are also present. H&E stain. bar = 80 µm. (G) Mast cell tumor. Fine metachromatic granules are dispersed in the cytoplasm. Toluidine blue stain. bar = 20 µm. (H) Fibrosarcoma. Note abundant collagen bundles. Masson's trichrome stain. bar = 20 µm. (I) Peripheral nerve sheath tumor. Spindloid neoplastic cells arranged in interwoven bundles are positive for vimentin. Avidin-biotin peroxidase complex method. bar = 20 µm.