Malignant melanoma of skin of upper limb, including shoulder

This code signifies a cancerous tumor originating from melanocytes, specifically located on the skin of the upper extremity, which includes the arm, forearm, hand, and shoulder. This aggressive form of skin cancer is characterized by uncontrolled growth of pigment-producing cells.

Apply this code when documentation confirms a diagnosis of malignant melanoma affecting any skin site on the upper limb, including the shoulder region. This diagnosis is typically established through biopsy and histopathological examination.

• Ensure the pathology report explicitly states "malignant melanoma" and specifies an upper limb location.
• Distinguish from benign melanocytic nevi or other non-melanoma skin cancers.
• Consider additional codes for laterality (e.g., left, right) if available in the ICD-9-CM system, though 172.6 does not specify.