A disadvantage with standard surgical excision is a reported higher recurrence rate of basal-cell cancers of the face, especially around the eyelids, nose, and facial structures. There is no clear approach, nor a clear research comparing the effectiveness of Mohs micrographic surgery versus surgical excision for BCC of the eye.For basal cell carcinoma excisions on the lower lip the wound can be covered with a keystone flap. A keystone flap is achieved by creating a flap below the defect and pulling it superiorly to cover the wound. This can be performed if there is enough skin laxity to cover the defect and adequate blood supply to the flap. Mohs surgery
For many new (primary) and all recurrent forms of basal cell carcinoma after previous surgery, especially on the head, neck, hands, feet, genitalia and anterior legs (shins), Mohs surgery should be considered.Mohs surgery (or Mohs micrographic surgery) is an outpatient procedure, developed by Frederic E. Mohs in the 1930s, in which the tumor is surgically excised and then immediately examined under a microscope. It is a form of pathology processing called CCPDMA, which means that the entire surgical margin (both edges and deep) is examined. During the surgery, after each removal of tissue and while the patient waits, the tissue is examined for cancer cells. That examination dictates the decision for additional tissue removal.
However, superficial basal-cell cancer can present as a red patch similar to eczema. Infiltrative or morpheaform basal-cell cancers can present as a skin thickening or scar tissue – making diagnosis difficult without using tactile sensation and a skin biopsy. It is often difficult to visually distinguish basal-cell cancer from acne scar, actinic elastosis, and recent cryodestruction inflammation. Cause
The majority of basal-cell carcinomas occur on sun-exposed areas of the body. Pathophysiology
Basal-cell carcinoma is named after the basal cells that populate the lowest layer of the epidermis due to the histological appearance of the cancer cells under the microscope. Nevertheless, not all basal-cell carcinomas actually originate within the basal layer. Basal-cell carcinomas are thought to develop from the folliculo–sebaceous–apocrine germinative cells known as trichoblasts. Trichoblastic carcinoma is a term used to describe a rare and potentially aggressive malignancy that is also thought to arise from trichoblasts and may resemble a benign trichoblastoma (differential diagnosis can be challenging). It has been suggested that lesions diagnosed as trichoblastic carcinoma may actually themselves be basal-cell carcinoma.Overexposure to sun leads to the formation of thymine dimers, a form of DNA damage. While DNA repair removes most UV-induced damage, not all crosslinks are excised. There is, therefore, cumulative DNA damage leading to mutations. Apart from the mutagenesis, overexposure to sunlight depresses the local immune system, possibly decreasing immune surveillance for new tumor cells. Basal-cell carcinomas can often come in association with other lesions of the skin, such as actinic keratosis, seborrheic keratosis, squamous cell carcinoma.