Melanoma is a serious form of skin cancer that originates in melanocytes, the cells responsible for producing skin pigment. While most melanomas appear on the skin’s surface, subcutaneous melanoma is a less common type that develops beneath the skin. Its unique presentation makes it challenging to identify, underscoring the importance of early detection.
Understanding Subcutaneous Melanoma
Subcutaneous melanoma forms in the deeper layers of the skin or fatty tissue. Unlike more common superficial spreading melanomas that present as irregular moles, this type often manifests as a lump or nodule that can be felt rather than seen. Its hidden nature means it may grow significantly before becoming noticeable, potentially allowing for more advanced progression.
Its growth pattern differs as it extends downward into the skin rather than spreading across the surface. This vertical growth can contribute to its potential for rapid progression.
General risk factors for melanoma also apply to the subcutaneous type:
Excessive exposure to ultraviolet (UV) radiation from the sun or tanning beds
A history of severe sunburns
Numerous moles
Fair skin, light hair, and eye color
A family history of melanoma
A weakened immune system
Identifying and Diagnosing Subcutaneous Melanoma
Identifying subcutaneous melanoma can be difficult because it does not always present with the typical “ABCDE” signs associated with surface moles (Asymmetry, Border irregularity, Color variation, Diameter over 6mm, Evolving). Instead, individuals might notice a firm, growing lump under the skin, which may or may not be discolored on the surface. This lump can sometimes be tender or painful to the touch.
Diagnosis begins with a thorough physical examination by a healthcare professional, who will assess any suspicious lumps or areas. If a subcutaneous lump is suspected, an excisional biopsy is the preferred method for diagnosis. This involves surgically removing the entire lump for microscopic examination to confirm the presence of cancer cells.
Imaging tests are often used to determine the extent of the tumor and check for spread. Ultrasound, MRI, and CT scans can help visualize the tumor’s depth and assess if it has spread to nearby tissues or distant organs. A sentinel lymph node biopsy may also be performed to determine if cancer cells have spread to the closest lymph nodes.
Treatment Approaches for Subcutaneous Melanoma
Surgical removal of the tumor, known as wide local excision, serves as the primary treatment for subcutaneous melanoma across all stages. This procedure involves removing the melanoma along with a margin of healthy tissue surrounding it to help ensure all cancer cells are eliminated. In some cases, a skin graft may be necessary to cover large surgical wounds.
Depending on the stage and characteristics of the melanoma, additional treatments, known as adjuvant therapies, may be recommended after surgery. Immunotherapy, such as PD-1 inhibitors, works by boosting the body’s immune system to fight cancer cells. Targeted therapy drugs are used when the melanoma cells have specific genetic mutations, blocking signals that promote cancer growth.
Radiation therapy may be used when surgical margins are not clear or for palliative care to relieve symptoms in advanced cases. Chemotherapy is a less common option for advanced cases or when other therapies are not suitable. The choice of treatment depends on individual patient factors and the disease’s progression, with a multidisciplinary team often collaborating to develop a personalized treatment plan.
Prognosis and Ongoing Care
The prognosis for subcutaneous melanoma is influenced by several factors, including the stage at diagnosis, the tumor’s thickness (Breslow depth), and whether ulceration or lymph node involvement is present. Tumors that are diagnosed at an earlier stage, are thinner, and have not spread to lymph nodes generally have a more favorable outlook. For localized melanoma, the 10-year survival rates vary significantly with thickness, ranging from approximately 92% for tumors 1.0 mm or less to 50% for those 4.0 mm or greater.
Ongoing care after treatment is important for monitoring for recurrence and detecting any new melanomas. Regular follow-up appointments typically include physical examinations and skin checks, with frequency varying based on the melanoma’s stage and risk of recurrence.
Imaging tests, such as CT scans and brain MRIs, may be recommended for higher stages to screen for recurrence. Patients are also encouraged to perform regular self-skin checks and practice sun protection, including using sunscreen and avoiding excessive UV exposure, as these measures contribute to long-term management and help prevent future skin cancers.