Other and unspecified malignant neoplasm of skin (C44) ICD-10-CM

A primary or metastatic malignant neoplasm involving the skin. Primary malignant skin neoplasms most often are carcinomas (either basal cell or squamous cell carcinomas) or melanomas. Metastatic malignant neoplasms to the skin include carcinomas and lymphomas.

The most frequently seen skin cancer. It arises from basal cells of the epidermis and pilosebaceous units. Clinically it is divided into the following types: nodular, ulcerative, superficial, multicentric, erythematous, and sclerosing or morphea-like. More than 95% of these carcinomas occur in patients over 40. They develop on hair-bearing skin, most commonly on sun-exposed areas. Approximately 85% are found on the head and neck and the remaining 15% on the trunk and extremities. Basal cell carcinoma usually grows in a slow and indolent fashion. However, if untreated, the tumor may invade the subcutaneous fat, skeletal muscle and bone. Distant metastases are rare. Excision, curettage and irradiation cure most basal cell carcinomas.

A carcinoma arising from the squamous cells of the epidermis. Skin squamous cell carcinoma is most commonly found on sun-exposed areas. The majority of the tumors are well-differentiated.

Of the 147 codes in this range, 101 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.

The range classifies other and unspecified malignant neoplasm of skin. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.