C44.521 Squamous cell carcinoma of skin of breast

Billable ICD-10-CM code, FY2026.

Applies from C44 Other and unspecified malignant neoplasm of skin

Includes

• malignant neoplasm of sebaceous glands
• malignant neoplasm of sweat glands

Excludes1 (never code together)

• Kaposi's sarcoma of skin (C46.0)
• malignant melanoma of skin (C43.-)
• malignant neoplasm of skin of genital organs (C51-C52, C60.-, C63.2)
• Merkel cell carcinoma (C4A.-)

Applies from C44.5 Other and unspecified malignant neoplasm of skin of trunk

Excludes1 (never code together)

• anus NOS (C21.0)
• scrotum (C63.2)

MS-DRG index

Defines the logic of DRG(s) 606-607 in MDC 09.

Approximate ICD-9-CM (GEMs)

• 173.52 Squamous cell carcinoma of skin of trunk, except scrotum (approximate)

Code annotations containing back-references to C44.521

Back-references to C44.521

• Type 1 Excludes: C50 Malignant neoplasm of breast ("skin of breast (C44.501, C44.511, C44.521, C44.591)")

Back-references to C44

• Type 1 Excludes: C76 Malignant neoplasm of other and ill-defined sites ("malignant neoplasm of skin (C44.-)")

Nearby codes

• C44.510 Basal cell carcinoma of anal skin
• C44.511 Basal cell carcinoma of skin of breast
• C44.519 Basal cell carcinoma of skin of other part of trunk
• C44.52 Squamous cell carcinoma of skin of trunk
• C44.520 Squamous cell carcinoma of anal skin
• C44.521 Squamous cell carcinoma of skin of breast (this code)
• C44.529 Squamous cell carcinoma of skin of other part of trunk
• C44.59 Other specified malignant neoplasm of skin of trunk
• C44.590 Other specified malignant neoplasm of anal skin
• C44.591 Other specified malignant neoplasm of skin of breast
• C44.599 Other specified malignant neoplasm of skin of other part of trunk