NON EXCISIONAL TECHNIQUES
Non-excisional treatment of lipomas, which is now common, includes steroid injections and liposuction.
Steroid injections result in local fat atrophy, thus shrinking (or, rarely, eliminating) the lipoma. Injections are best performed on lipomas less than 1 inch in diameter. A one-to-one mixture of 1 percent lidocaine (Xylocaine) and triamcinolone acetonide (Kenalog), in a dosage of 10 mg per Ml, is injected into the center of the lesion. This procedure may be repeated several times at monthly intervals. The volume of steroid depends on the size of the lipoma, with an average of 1 to 3 mL of total volume administered. The number of injections depends on the response, which is expected to occur within three to four weeks. Complications, which are rare, are the result of the medication or the procedure, and can be prevented by injecting the smallest total amount possible and by positioning the needle so that it is in the center of the lipoma.
Liposuction can be used to remove small or large lipomatous growths, particularly those in locations where large scars should be avoided. Complete elimination of the growth is difficult to achieve with liposuction. Office procedure using a 16-gauge needle and a large syringe may be safer than large-cannula liposuction. Diluted lidocaine usually provides adequate anaesthesia for office liposuction.
Small lipomas can be removed by enucleation. A 3-mm to 4-mm incision is made over the lipoma. A curette is placed inside the wound and used to free the lipoma from the surrounding tissue, Once freed, the tumor is enucleated through the incision using the curette. Suctures generally are not needed, and a pressure dressing is applied to prevent hematoma formation.
Larger lipomas are best removed through incisions made in the skin overlying the lipoma. The incisions are configured like a fusiform excision following the skin tension lines and are smaller than the underlying tumor. The central island of skin to be excised is grasped with a hemostat, or Allis clamp, which is used to provide traction for the removal of the tumor. Dissection is then performed beneath the subcutaneous fat to the tumor. Any tissue cutting is performed under direct visualization using a #15 scalpel or scissors around the lipoma. Care must be taken to avoid nerves or blood vessels that may lie just beneath the tumor.
The microscopic subtypes have no clinical significance with respect to the behaviour of tumors. Infiltrating lipomas are an exception, as the absence of a capsule and their ability to infiltrate the surrounding skeletal muscles represent a high-risk factor for recurrence. Depending upon the site, lipomas can be categorized into superficial, deep and periosteal. Although rare, the malignant transformation of oral lipomas into liposarcomas has been reported. Intramuscular location seems to be a risk factor for malignancy. Immunohistochemical detection of a aP2, a protein expressed by lipoblasts, could assist in differential diagnosis.
A histological examination after removal of lipomas is imperative to exclude lipo sarcomatous degeneration, to detect the absence of a capsule, which requires a constant follow-up due to a high probability of recurrence. Furthermore, the small number of reviews regarding lipomatous tumors of the oral cavity suggests the necessity of more attention on the soft tissue tumors that could affect the oral cavity. Thus, a possible expansion of the subtype classification and description if topographic issues may be revised in the future.