The histiocytoma is a tumor originating from what is called a “Langerhans cell.” This Langerhans cells live in the skin and serve as part of the immune system by processing incoming antigens and presenting them to other immunologic cells. The histiocytoma is especially common in Labrador retrievers, Staffordshire terriers, Boxers, and Dachshunds. It is not related to the malignant process called “histiocytosis.”
WHAT MIGHT A GROWTH WITH THIS APPEARANCE BE?
There are several possibilities for this type of growth, often termed a "button" growth. The ringworm fungus, for example, can produce some raised round reactions called “kerions” which can look similar. The mast cell tumor, which is highly inflammatory, sometimes malignant, and must be excised widely so as to prevent recurrence, can have an identical appearance. The melanoma can also appear as a similar lesion. If the patient is young, the chances are good that a benign process is afoot but some testing will be needed to be sure.
FINDING OUT FOR SURE:
Biopsy may require sedation depending on the location of the growth. Sometimes a local anesthetic is enough. A small piece of tissue is snipped off (or the entire lesion can be removed if it is small enough) and sent to the lab for analysis. In a few days we will know for sure exactly what the growth is.
Less costly but also less accurately, cells can be withdrawn from the lesion by a needle or simply collected from the tumor surface by pressing a microscope slide to the tumor surface. This omits the ability to see the architecture of the tissue and just the cells are available for examination. This may be enough for the lab to confirm the identity of the growth in question.
WHAT TO DO WITH A HISTIOCYTOMA
On the average, a histiocytoma undergoes regression by itself within three months. This process may be itchy or may lead to minor infection. Removal of the histiocytoma is the fastest route to resolution but, since they do go away on their own, leaving the growth alone is reasonable (as long as we know for sure it is a histiocytoma). Topical therapy with a product containing DMSO and a cortisone derivative is helpful in controlling symptoms of irritation.
Page last updated: 10/7/2016