Local anesthetic is usually used or occasionally general anesthetic is required, especially for children or for deep, large cysts. The lump may be a sebaceous (epidermoid) or dermoid cyst, a lipoma or another type of cutaneous or subcutaneous lesion. It is usually completely excised with a margin of normal tissue to adequately remove all of the cyst wall or lipoma, without incising into the mass, to reduce the risk of recurrence. The wound is usually closed in layers and the skin sutured. Histopathological examination is then performed.

The location and consistency of the lump may vary, but is usually over the head, neck, or back regions. Excessively fixed, very deep or ill-defined lumps may be difficult to excise. Lumps close to nerves or vessels present danger of injury or division to these structures. Occasionally, lipomas may insinuate between muscle groups, nerves, and other structures, increasing operative difficulty. Dermoid cysts may (embryologically) communicate through the skull with the dura (external angular dermoid cyst) and pose some risk of intracranial infection (Table 3.2).

The risk of surgery should always be balanced with the benefits. Inflammation or recurrent infection mainly represent an inconvenience of variable importance, but in some people, such as diabetics or immunosuppressed patients, can be life threatening. Cosmetic considerations may be an indication for surgery, but the risk of a non-cosmetic scar, especially in situations of previous radiotherapy to the area, is important to discuss prior to surgery, as is the potential for nerve injury (sensory or motor). Postoperative infection is useful to consider versus the risk of recurrent infections of the cyst without surgery. Many cysts never become inflamed or infected, while others incur repeated inflammation, although both are often unpredictable. The size and location of the cyst may dictate the need for drain tubes, and the effects of scarring or poor cosmesis, especially in situations of previous radiotherapy to the area.

Major complications are rare; however, infection may be local in the wound, with or without wound dehiscence, or very rarely become systemic, either with or without further surgery. The risk of infection postoperatively is often reduced by treating an active infection with appropriate antibiotic therapy for 2–3 weeks prior to surgery to settle the infection. Diabetic, immunosuppressed, or those traveling to remote areas may prompt earlier surgical intervention. A risk to warn patients of is that of oozing and bleeding which is usually minor and this typically ceases with application of direct pressure for one or two 20-min intervals. Misdiagnosis is a potential problem in some instances with a variety of other subcutaneous lesions that may mimic a sebaceous cyst, most notably metastatic melanoma. Imaging and needle cytology may assist where appropriate, for uncertain lesions, to reduce the risk from inappropriate surgery that may possibly jeopardize the outcome. However, this considered, the usual clinical diagnostic history and signs of a sebaceous cyst are correct the majority of the time. Nerve injury is rare, but can cause substantial parasthesia or discomfort. Wound scarring with poor cosmesis can occur, as can hypertrophic or keloidal scarring. Major complications do not feature the majority of the time.

General anesthetic or local anesthetic is used. The aim is to excise a margin of normal skin around a melanoma site to reduce risk of local recurrence. The margin will depend on location on the body and tumor thickness. Fascia may need to be included in the excision as may superficial veins, arteries, or nerves. Primary closure is usually performed, but flap repair or grafting may be required. The procedure may be combined with sentinel node biopsy. Histopathological examination is then performed.

The site where the excision is being performed will dictate the ease or difficulty of wide local excision (WLE). Lesions on the nose, eyelids, ears, face, genitals, distal limbs, or in the oral cavity or anus are more complex to obtain an adequate margin than lesions where more skin is available, such as abdomen and back. The presence of nerves and other vital structures adds complexity since these may be injured or need to be sacrificed (Table 3.3).

The risk of surgery should always be balanced with the benefits. The usual reason for wider excision of skin around a melanoma site is to reduce risk of recurrence. Most complications and consequences are relatively minor. Infection mainly represents an inconvenience of variable importance, but in some people, such as diabetics or immunosuppressed patients, can be life threatening. The risk of a non-cosmetic scar is important to discuss prior to surgery, especially in situations of previous radiotherapy to the area, as is the potential for nerve injury (sensory or motor), especially on the face (facial nerve) if deep, or around the eye where retraction can be a problem. Bleeding is rarely a problem, but significant bleeds can occur especially in elderly or anticoagulated patients. Flap or edge necrosis is rarely a problem, but may necessitate further surgery and should be mentioned to the patient, especially in situations of previous radiotherapy to the area. Skin graft loss is more likely in the lower limb because of poorer vascularity.