Pathologic Report of 29 Necropsies on Dogs with Mastocytoma

Abstract

At necropsy 28 of 29 dogs with cutaneous mastocytoma had internal accumulations of mast cells in various organs. The order of decreasing incidence in these organs was: regional lymph nodes, spleen, liver, bone marrow, kidneys, lungs, and heart. No correlation was obvious between the size of the external lesions and the extent of internal involvement. A good correlation existed between the degree of anaplasia of the initial external tumor and the extent of subsequent internal involvement. Other significant lesions observed in these dogs included a diffuse plasmacytosis and a chronic focal glomerulitis. The distribution of neoplastic mast cells in some dogs inferred a multicentric origin. The possibility of an autoimmune reaction in these dogs is briefly discussed.

Variation among Pathologists in the Histologic Grading of Canine Cutaneous Mast Cell Tumors with Uniform Use of a Single Grading Reference

“…It has been recognized for more than 30 years that histologic grading is prognostic for the behavior of canine cutaneous MCTs. 3,6,10 The 2 most widely recognized grading systems classify MCTs into 3 grades based on histologic characteristics, including cellularity, cell morphology, invasiveness, mitotic activity, and stromal reaction. 3,10 Both grading systems correlate with the survival rate of canine patients with MCTs and histologic grade is the most important factor in determining the staging tests and adjunctive therapy that will be recommended for a dog with a cutaneous MCT.…”

Variation among Pathologists in Histologic Grading of Canine Cutaneous Mast Cell Tumors

“…It has been recognized for more than 30 years that histologic grading is prognostic for the behavior of canine cutaneous MCTs. 2,4,7 The 2 most widely recognized grading systems classify MCTs into 3 grades based on histologic characteristics that include: cellularity, cell morphology, invasiveness, mitotic activity, and stromal reaction. 2,7 Both grading systems correlate with the survival rate of canine patients with MCT.…”

Extracutaneous Mast-Cell Tumor in the Dog

“…Neoplasms of mast-cell origin usually affect the skin, and are among the most common cutaneous neoplasms in the dog [6, 101. In 76% of these tumors the regional lymph nodes, and less commonly other visceral organs, become involved secondarily [6]. Primary sites of canine mast-cell tumor other than the skin, including the oral cavity [3,5,121 and larynx [l], have been reported rarely, and a mast-cell tumor arising from the intestines of a dog has been described recently [ 1 11.…”