Histiocytomas are rapidly growing tumors found in dogs 1 - 3 years of age. They occur anywhere on the body.
These benign tumors are dome-shaped, raised, hairless surface growths that are not painful. Because of their appearance, that are often called button tumors.
The typical signs of histiocytosis are lethargy, weight loss, and enlargement of the liver, spleen, and lymph nodes.
These tumors are more common on short haired dogs.
Histiocytosis is a rare malignant cancer in which histiocytes (large cells found in normal connective tissue) are widely dispersed throughout the subcutaneous tissue and internal organs, occasionally forming nodules.
The disease tends to affect male dogs of certain breeds at 3 - 8 years of age. In Bernese Mountain Dogs, the disease is inherited as a polygenic trait, and accounts for 25% of all tumors in that breed. Flat-Coated Retrievers are also unusually susceptible to this type of cancer.
It is often impossible to determine whether a skin tumor is benign or malignant by appearance alone. The only conclusive way to make a diagnosis is by biopsy, a procedure in which tissue or cells are removed by your veterinarian and examined under a microscope by a veterinary pathologist.
Most histiocytomas disappear spontaneously within 1 - 2 months. Those that persist should be removed for diagnosis.
Histiocytosis may respond to chemotherapy.
Please contact your veterinarian if you have questions regarding this condition.
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