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 results when Langerhans cells become tumorous and generate a visible growth. This growth is ultimately recognized by the immune system as something to get rid of. It becomes infiltrated by T-lymphocytes and is destroyed.
Histiocytomas especially common in Labrador retrievers, Staffordshire terriers, Boxers, and Dachshunds. The histiocytoma 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:
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. Any growth believed to be a histiocytoma that is still present after 3 months should be removed. Any histiocytoma that is eroded or seems uncomfortable should be removed rather than waiting through the regression process.
Page last updated: 7/9/2021