From Dog
Microscopic appearance of a thyroid carcinosarcoma, showing spindle-shaped neoplastic cells lining and interspersed between irregular trabeculae of osteoid (arrow)[1]

Carcinosarcoma are a rare malignant canine tumor, usually affecting older dogs and characterized by tumors composed of both carcinoma and sarcoma with osseous elements[1].

These tumors consist of both malignant epithelial (follicular cells) and mesenchymal (usually osteogenic or cartilaginous or both) elements[2].

These tumors can be found in the thyroid gland, mammary gland (mammary carcinosarcoma)[3], lung[4], salivary gland[5], ceruminous gland[6], and eyelid[7].

These tumors are relatively aggressive and tend to metastasize and invade local tissues and surgical extirpation is not always successful, necessitating adjunctive chemotherapy and radiation therapy.


  1. 1.0 1.1 Grubor B & Haynes JS (2005) Thyroid carcinosarcoma in a dog. Vet Pathol 42(1):84-87
  2. Capen CC (2002) Tumors of the endocrine glands. In: Tumors in Domestic Animals, ed. Meuten DJ, 4th ed., pp. 638–684. Iowa State Press, Ames, IA
  3. Benjamin SA et al (1999) Classification and behavior of canine mammary epithelial neoplasms based on life-span observations in Beagles. Vet Pathol 36:423–436
  4. Salas G et al (2002) Lung carcinosarcoma in a dog: gross and microscopic examination. Vet J 163:331–334
  5. Perez-Martinez C et al (2000) Malignant fibrous histiocytoma (giant cell type) associated with a malignant mixed tumor in the salivary gland of a dog. Vet Pathol 37:350–353
  6. Moisan PG & Watson GL (1996) Ceruminous gland tumors in dogs and cats: a review of 124 cases. J Am Anim Hosp Assoc 32:449–453
  7. Hirai T et al (1997) Apocrine gland tumor of the eyelid in a dog. Vet Pathol 34:232–234