Lipomas are benign, adipose tissue tumors that can arise anywhere on the body. Lipomas frequently are encountered on the upper half of the body, with common sites including the head, neck, shoulders, and back. Most lesions are confined to the subcutaneous tissues, but lesions occasionally penetrate between fascial planes and even into muscle. Subfascial lipomas are most commonly found in the neck.
Lipomas can vary from the size of a pea to that of a soccer ball. The tumors are composed of lobules of fat encased in a thick, fibrous capsule. The adipose tissue within lipomas is often indistinguishable from normal fat. Delineation of a lipoma may be achieved by searching for the limits of the capsule. Lobules are connected by a thinner stroma or fibrous bands that can extend to deep fascia or the skin and produce dimpling. These bands may prevent easy enucleation of an encapsulated lipoma.
Lipomas often produce a rounded mass that protrudes above surrounding skin. On palpation, the lesions usually feel smooth, lobulated, and compressible. Some clinicians describe a characteristic “doughy” feel to the lesions. Lipomas are generally nontender, although adiposis dolorosa (i.e., Dercum's disease) is a condition with painful or tender truncal or extremity lipomas. Dercum's disease is most commonly encountered in women in the later reproductive years. Lipomas often grow slowly and can increase in size if the patient gains weight. During times of weight loss or starvation, lipomas do not decrease in size.
The presence of multiple lipomas is known as lipomatosis, and the condition is more common in men. Hereditary multiple lipomatosis is an autosomal dominant condition that produces widespread lipomas over the extremities and trunk. Madelung's disease refers to benign symmetric lipomatosis of the head, neck, shoulders, and proximal upper extremities. It is uncommon to find malignancy in a lipoma (i.e., liposarcoma) when a patient displays multiple lipomas. Liposarcoma is found in 1% of lipomas and is most commonly encountered in lesions on the lower extremities, shoulders, and retroperitoneal areas. Other risk factors for liposarcoma include large size (>5 cm), associated calcification, rapid growth, or invasion into nearby structures or down through fascia and into muscle.
Nonexcisional techniques for lipoma removal include steroid injection and liposuction. Steroid injections produce fat atrophy and are best performed on
smaller lesions (<1 inch in diameter). Often, multiple injections given over 1 to 3 months are required for an adequate response. Liposuction can be performed in the office using large-gauge needles attached to 20-mL or larger syringes (after field block anesthesia using diluted lidocaine) or in the operating room using standard suction curettes. Complete eradication of the lipoma cells can be difficult to achieve with liposuction, and rapid regrowth of the lesion may result. Liposuction is an attractive option for lipomas located in areas where large scars should be avoided (e.g., face).
Small lipomas are often surrounded by a well-developed and easily identified capsule. After the creation of a small incision, these lesions may be extruded through the wound with the application of pressure to surrounding skin. Enucleation can also be achieved by combining the use of a dermal curette with pressure. Larger lipomas often do not display such a well-defined capsule, and distinguishing normal from lipomatous fat can be a challenge.
Large lipomas can be removed by leaving the top of the tumor attached to a small island of overlying skin. This skin can be grasped and retracted when dissecting around the lipoma. The deeper yellow color (due to increased density) often seen in lipomas can help visually identify the tumor. Skin markings made before the procedure also aid in identifying the extent of the tumor. Care must be exerted when dissecting the base of the wound to avoid creating trauma to deep structures such as arteries, nerves, or muscle. After the tumor is removed, inspect the base of the wound carefully to identify any lobules of tumor that may have been left.
Small bleeding vessels at the base of the wound can be clamped with hemostats or tied off with absorbable sutures in a figure-of-eight pattern. The wound bed should be dry (i.e., bleeding controlled) before closure is attempted. Deep wounds often require the use of larger-gauge absorbable sutures, because significant tension may be required to close the dead space created by removal of a large tumor. Historically, Penrose drains were used to facilitate blood and fluid drainage from these deep wounds. Drains increase bacterial counts in wounds and often are not needed if meticulous hemostasis and suture closure of the deep wound are properly performed.
Palpate the tumor, and draw an outline of the tumor on the skin with a skin marking pen. Draw a fusiform excision that overlies the center of the tumor, that is smaller than the underlying lipoma, and whose long axis coincides with the nearby lines of least skin tension. The fusiform incision should be designed to be about two thirds of the diameter of the underlying lipoma.
(1) Palpate the tumor, and draw an outline of the tumor on the skin with a skin marking pen.
PITFALL: Do not draw on the skin using ballpoint pens. Ballpoint pens can traumatize skin, and the ink tends to wash off when the skin preparation is performed. Using a surgical skin marking pen is likely to provide an outline of the tumor that will guide the excision and last throughout the surgery.
Field block anesthesia can be achieved by injecting beneath and lateral to the outlined lesion using long (1¼ or 1½ inch) needles. A sufficient volume of 1% lidocaine should be administered around the periphery of the lesion to surround the tumor.
(2) Inject 1% lidocaine beneath and lateral to the outlined lesion using long needles.
Incise the skin through the fusiform markings, but do not undermine the central fusiform island of skin. Carry the vertical incision down to the level of the fat or to the lipoma capsule. Use an Allis clamp or large Kelly clamp to grasp the center of the island of skin, which remains attached to the underlying lipoma. Use the clamp to provide traction to undermine lateral skin and to dissect around the lipoma.
(3) Incise the skin through the fusiform markings, but do not undermine the central fusiform island of skin.
PITFALL: Some physicians prefer to make a simple incision through skin rather than create a fusiform island of skin. Traction applied directly on the lipoma produces tearing through the tissue, and closure after large lipoma removal leaves redundant skin unless a fusiform section of skin is removed.
Use the gloved finger, scissors, or scalpel blade to carefully dissect around the entire lesion. The original skin markings should be used to guide the dissection.
(4) Use the gloved finger, scissors, or scalpel blade to carefully dissect around the entire lesion.
PITFALL: Care must be taken to avoid damaging structures beneath the lipoma, such as nerves, arteries, or muscle. Because visualization may be poor beneath the lesion, blunt dissection is often advocated for freeing the underside of the lipoma. A finger is often a sensitive and effective tool for this part of the operation.
The entire lipoma can often be delivered through the smaller fusiform skin incision.
(5) The lipoma can often be removed in its entirety through the smaller fusiform skin incision.
PITFALL: Bleeding may occur during dissection and delivery of the tumor. Bleeding vessels can be briefly clamped with small hemostats to provide adequate hemostasis before wound closure.
Multiple, interrupted, deeply buried sutures are placed to close the large defect after removal of the lipoma. Large-caliber absorbable suture (e.g., 3-0 or 4-0 polyglycan) is used and should grasp a significant portion of lateral tissue so that it will not tear when closing the deep space. Significant tension may be placed on these sutures when closing large spaces.
(6) Multiple, interrupted, deeply buried, large-caliber, absorbable sutures are placed to close the large defect.
Standard skin closure is performed for the fusiform skin defect.
(7) Standard skin closure is performed for the fusiform skin defect.
Small lipomas (<3 cm in diameter) can be treated with steroid injections that produce atrophy in the adipose tissue. A 1:1 mixture of 1% lidocaine and triamcinolone acetonide (10 mg/mL) can be injected into the center of the lesion.
(8) Small lipomas can be treated with steroid injections that produce atrophy in the adipose tissue.
Small lipomas also can be treated with enucleation. A 4-mm biopsy punch creates a skin defect over the top of the lesion. A skin curette is used to free the lesion from surrounding tissue and then used to deliver (i.e., enucleate) the tumor through the small skin opening. Suturing generally is not needed, and a pressure dressing is applied.
(9) Small lipomas can also be treated with enucleation.
Lipoma removal can be reported using the benign excision codes (11400–11446), which are listed in Chapter 12. The benign excision codes include removal of the benign subcutaneous lesion with simple skin closure. Enucleation is usually reported with these codes. Intralesional injection is reported using the 11900 code. Intermediate closure codes can be added to an excision code if deeply buried subcutaneous sutures are placed. Intermediate codes are cited for the following areas: scalp, axilla, trunk, arms, or legs (excluding hands and feet) (SATAL); neck, hands, feet, or external genitalia (NHFG); and face, ears, eyelids, nose, lips, or mucous membranes (FEENLMM).
Intermediate Repair: Layered Closure
Tumor Excision Codes
Lipomas can infiltrate into deeper tissues, and the excision of such lesions may be more appropriately reported using tumor excision codes.
INSTRUMENT AND MATERIALS ORDERING
A standard surgery tray can be used for removal of lipomas (see Appendix A). Consider adding two or three larger hemostats (e.g., Kelly clamps) to the surgery tray to allow easier grasping of the lipoma. Suggested suture removal times are listed in Appendix C, and a suggested anesthesia tray that can be used for this procedure is listed in Appendix G. Skin preparation recommendations appear in Appendix H.
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