D03.61

Clinical Causes: Excessive exposure to ultraviolet (UV) radiation from sunlight or tanning beds Genetic factors that predispose individuals to melanoma Previous history of skin cancers or atypical moles Fair skin, light hair, or eye color, which are more susceptible to UV damage Weakened immune system, which can impair the body’s ability to detect and destroy abnormal cells Presence of numerous moles or unusual moles (dysplastic nevi)

Key Symptoms: A new or changing mole or skin discoloration on the right upper limb or shoulder area Asymmetry in shape or uneven borders of the pigmented skin patch Multiple colors within a single lesion, such as black, brown, or tan shades A mole that is larger than 6 millimeters (about the size of a pencil eraser) Lesions that evolve in appearance, texture, or size over time Itching, tenderness, or bleeding in the affected area (though often asymptomatic)

Diagnosis Path: Diagnosis begins with a thorough skin examination by a healthcare professional, who assesses the size, shape, color, and texture of suspicious moles or patches. If melanoma in situ is suspected, a biopsy is performed, typically involving removal of a small tissue sample from the lesion for microscopic examination. The pathologist then confirms whether the cells are confined to the epidermis and whether they show features characteristic of melanoma in situ. Additional imaging tests are generally not necessary unless further invasive disease is suspected, which is rare at this stage.

Treatment Protocols: The primary treatment for melanoma in situ of the right upper limb, including the shoulder, is surgical excision. Surgical removal ensures complete elimination of abnormal cells with clear margins to prevent recurrence. Depending on the size and location of the lesion, several techniques may be employed, such as: - **Standard excisional surgery** — removing the lesion with some healthy tissue around it - **Mohs micrographic surgery** — particularly useful for lesions in cosmetically sensitive areas or with ill-defined borders, allowing tissue conservation and precise removal Follow-up care involves regular skin exams to monitor for new abnormalities or recurrence. Additional treatments are rarely required unless further invasive features are found or if the lesion recurs. Preventive strategies to reduce UV exposure are recommended to lower the risk of future skin cancers.