A mastocytoma or mast cell tumor is  a type of round-cell tumor consisting of mast cells. It is found in humans and many animal species; it also can refer to an accumulation or nodule of mast cells that resembles a tumor. Mast cells originate from the bone marrow and are normally found throughout the connective tissue of the body as normal components of the immune system. As they release histamine, they are associated with allergic reactions. Mast cells also respond to tissue trauma. Mast cell granules contain histamine, heparin, platelet-activating factor, and other substances. Disseminated mastocytosis is rarely seen in young dogs and cats, while mast cell tumors are usually skin tumors in older dogs and cats. Although not always malignant, they do have the potential to be. Up to 25 percent of skin tumors in dogs are mast cell tumors, with a similar number in cats. Signs and symptoms
Humans
When mastocytomas affect humans, they are typically found in skin. They usually occur as a single lesion on the trunk or wrist. Although it is rare, mastocytomas are sometimes found in the lung. It can also affect children. Other animals
Mast cell tumors are known among veterinary oncologists as the great pretenders because their appearance can be varied, from a wart-like nodule to a soft subcutaneous lump (similar on palpation to a benign lipoma) to an ulcerated skin mass. Most mast cell tumors are small, raised lumps on the skin. They may be hairless, ulcerated, or itchy.
Long-term studies of adults with post-surgical clubfeet, especially those needing multiple surgeries, show that they may not fare as well in the long term. Some people may require additional surgeries as they age, though there is some dispute as to the effectiveness of such surgeries, in light of the prevalence of scar tissue present from earlier surgeries. Developing world
Despite effective treatments, children in LMICs face many barriers such as limited access to equipment (specifically casting materials and abduction braces), shortages of healthcare professionals, and low education levels and socioeconomic status amongst caregivers and families. These factors make it difficult to detect and diagnose children with clubfoot, connect them to care, and train their caregivers to follow the proper treatment and return for follow-up visits. It is estimated that only 15% of those diagnosed with clubfoot receive treatment.In an effort to reduce the burden of clubfoot in LMICs, there have been initiatives to improve early diagnosis, organize high-volume Ponseti casting centers, utilize mid-level practitioners and non-physician health workers, engage families in care, and provide local follow-up in the persons community. Cultural references
Hippolyte Tautain, the stableman at the Lion DOr public house in the 1856 novel Madame Bovary by Gustave Flaubert, has clubfoot. Charles Bovary tries to correct it, but the procedure is unsuccessful, and Tautain must have an amputation. Philip Carey, the main character of the 1915 novel Of Human Bondage by W. Somerset Maugham, has clubfoot. It is a central theme of the work. Velma, a character in the 1941 film High Sierra, has clubfoot.