Inflammatory carcinomas describe tumors that are fast growing and have bruising, edema, and pain, and can also cause disseminated intravascular coagulation. They are the most malignant type of canine mammary tumor.Malignant tumors are also subdivided histopathologically into those showing blood vessel wall invasion and those that do not. Without blood vessel wall invasion there is a better prognosis. Dogs with noninvasive adenocarcinomas have an average survival time of two years, while dogs with invasive adenocarcinomas have an average survival time of one year. Tumor size also affects the prognosis, in that dogs with tumors greater than five centimeters have a greater chance of lymph node metastasis. Tumor type is also important. Sarcomas and carcinosarcomas carry an average survival time of nine to twelve months. Inflammatory carcinomas have a very poor prognosis, and have usually metastasized by the time of diagnosis. Metastasis for any malignant mammary tumor is usually to the regional lymph nodes and lungs.The molecular carcinogenesis of canine mammary tumors are not completely understand. However, the increasing information on molecular pathways involved in the carcinogenesis of this canine tumor has potential to complement and refine the current diagnostic and therapeutic approach to this tumor type. Furthermore, current data show that significant similarities and differences exist between canine and human mammary tumors at the molecular level. Diagnosis and treatment
Appearance and location of the tumor is enough to identify it as a mammary tumor. Biopsy will give type and invasiveness of the tumor.
According to one study, cats with tumors less than three cm had an average survival time of 21 months, and cats with tumors greater than three cm had an average survival of 12 months. About 10 percent of cat mammary tumors have estrogen receptors, so spaying at the time of surgery has little effect on recurrence or survival time. Metastasis tends to be to the lungs and lymph nodes, and rarely to bone. Diagnosis and treatment is similar to the dog. There is a better prognosis with bilateral radical surgery (removing both mammary chains) than with more conservative surgery. Doxorubicin has shown some promise in treatment. In rats
Most mammary tumors in rats are benign fibroadenomas, which are also the most common tumor in the rat. Less than 10 percent are adenocarcinomas. They occur in male and female rats. The tumors can be large and occur anywhere on the trunk. There is a good prognosis with surgery. Spayed rats have a decreased risk of developing mammary tumors. In mice
Most mammary tumors in mice are adenocarcinomas. They can be caused by viral infection. Recurrence rates are high, and therefore there is a poor prognosis. There is frequently local tissue invasion and metastasis to the lungs. A well known tumor virus of the mouse is the mouse mammary tumor virus, which may be the most common cause of this tumor in mice. In other animals
Ferrets: Mammary tumors are rare in ferrets. Appearance tends to be a soft, dark colored lump.