The procedure was performed in case the clitoris, or nymphê, grew too large or triggered sexual desire when rubbing against clothing. "On this account, it seemed proper to the Egyptians to remove it before it became greatly enlarged," Aëtius wrote, "especially at that time when the girls were about to be married":

The surgery is performed in this way: Have the girl sit on a chair while a muscled young man standing behind her places his arms below the girls thighs. Have him separate and steady her legs and whole body. Standing in front and taking hold of the clitoris with a broad-mouthed forceps in his left hand, the surgeon stretches it outward, while with the right hand, he cuts it off at the point next to the pincers of the forceps. It is proper to let a length remain from that cut off, about the size of the membrane thats between the nostrils, so as to take away the excess material only; as I have said, the part to be removed is at that point just above the pincers of the forceps. Because the clitoris is a skinlike structure and stretches out excessively, do not cut off too much, as a urinary fistula may result from cutting such large growths too deeply.
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.