Skin Lumps are lesions that can grow on or under the skin. The Skin is one of the largest body organ by surface area and a variety of lesions can arise from it. Some skin lumps may appear on the skin but they actually arise from deeper structures like the bone, joints or muscle.
Skin Lumps are best divided into Benign and Malignant (Cancerous) lumps.
Benign lumps account for the vast majority of skin lesions and can occur at all ages. The common lumps (accounting for over 90% of benign lumps) include the following:
Malignant lumps are in the minority and tend to occur in the older population. The common skin cancers include the following:
A sebaceous cyst is formed when a sweat gland leading to the skin surface is blocked. This leads to the accumulation of sebum, hence forming a cyst. Sebum is secreted onto the skin and helps in keeping the skin waterproof.
Sebaceous cysts can occur in any part of the body, ranging from the scalp and face to the limbs and torso and including the buttock region.
A sebaceous cyst is a benign skin lump with almost zero chance of cancerous change.
Due to the superficial location of a sebaceous cyst just underneath the skin, it can be usually easily removed under local anesthesia.
A lipoma is a benign growth of fatty tissue. Like the sebaceous cyst, the lipoma is usually benign, with only a very small proportion having cancerous change. The only confirmatory test will be for complete removal of the lipoma with susequent histological assessement in the lab.
The majority of lipomas are located superficially and can be removed under local anesthesia. General anesthesia is needed for large lipomas (>7-10cm) or deep seated lipomas (usually over the back of the neck and the upper back).
Fibromas and Neuromas are benign growths of fibrous tissue and nerve tissue respectively. These are also overwhelmingly benign and are removed in a similar fashion as lipomas.
Skin tags are protuberant growths from the surface of the skin and usually have a stalk and a head. There can be some surface ulceration or abrasion of the head in larger skin tags.
Skin tags are benign growths and are easily removed under local anesthesia.
A viral wart can look similar to a skin tag, though the viral wart usually closely resembles a cauliflower-like growth.
Viral warts are usually present in the lower body, close to the genital and anal regions. They can be present singly or in large clumps.
A viral wart is usually caused by the human papilloma virus (HPV) and has the possibility of recurring after removal. It is necessary to apply an anti-viral cream after removal to reduce recurrence.
Single or small warts can be removed under local anesthesia while warts covering a large area will need general anesthesia for complete removal.
Moles are benign pigmented growths on the skin. They arise due to a concentration of melanocytes in the same area. Melanocytes produce melanin which gives the characteristic brown to dark brown colour of moles. Moles are essentially benign growths, though any worrying symptoms such as rapid growth, itchiness, pain and easy bleeding when scratched all point to a possibility of cancerous change. This is explained further under the Malignant Melanoma section below.
Most moles can be removed under local anesthesia. Anti-scarring cream and sunblock is often applied for a period of time after surgery to reduce scarring and scar pigmentation.
A Squamous Cell Carcinoma (SCC) is a cancerous growth of the skin. It can occur on any part of the skin, though commoner on the sun exposed areas. A SCC can appear in many forms, ranging from a flat reddish patch with some skin scales to a shallow skin ucler to a protuberant irregular-looking growth.
A SCC is a slow growing tumor with a propsensity to spread to the lymph nodes in the later stages. It is important to seek medical consult for any abnormal skin patches, particulaly if it is itchy, painful or bleeds easily. An early SCC may look harmless, but if treated early, a complete removal can easily give a survival of more than 80%
Some SCC can be found in areas with long term ulceration. The most common example is that of the SCC that develops in patients with chronic varicose veins of the leg with non-healing ulcers. A SCC can certainly be found in other areas like the oral cavity, including the tongue and the palate. It usually presents as a non-healing ulcer in these areas.
The treatment of SCC of the skin is a wide excision around the tumour with a 1cm circumferential margin. For sensitive areas like the face, a special technique known as Mohs surgery is needed to minimise the amount of skin removed while ensuring adequate cancer-free margins.
A Basal cell carcinoma (BCC) is another common skin cancer. Together with SCC, they constitute the two commonest skin cancers.
Similar to a SCC, the BCC can manifest in a variety of appearances, ranging from a ‘normal’ looking reddish nodule to a smooth solid nodule to a irregular looking ‘eaten out’ ulcer.
A BCC is what we term a locally invasive cancer. A BCC will grow and erode into the underlying muscle and bone, leaving a ‘eaten out’ appearance. Spread to lymph nodes or to distant organs usally occur very late into the disease
A BCC is very curable when detected early. The cure rates are similar to an SCC, though the recurrence rates are higher.
The treatment of BCC of the skin is similar to a SCC, except that the circumferential margins are potentially extended to 2cm.
Malignant melanoma (MM) is a very aggressive skin tumor. It arises from the melanocyte-containing layer of the skin. The melanocytes are the cells that produce the pigment of our skin and also our moles. Hence, a MM can arise from an existing mole that can be around for many years, or it can appear as a fast growing new mole. MM can arise in any part of the skin though it is commoner on sun exposed areas. In addition, MM can arise in areas like the esophagus or anus that are not exposed to the sun.
For MM that arise in an existing mole, the individual will notice a sudden change in the size and shape of the mole, together with associated itchiness, pain or easy bleeding upon scratching. It is important to notice these symptoms, regardless of how long the mole has been on the body. For MM that develop as a new mole, the same symptoms exist, though individuals may detect it earlier as it is never present previously in that location.
A MM is an aggressive cancer that spreads early to the lymph nodes and subsequently to distant organs, constituting a metastases.
The treatment for a MM is for a wide excision of potentially 2cm circumferential margins together with a possibility of lymph node clearance. It is important that staging of the MM is performed before the surgery with CT and PET scans. There is a potential for immunotherapy in MM.