C50.21

Malignant neoplasm of upper-inner quadrant of breast, female

FY2027Chapter 2: Neoplasms/C50 Malignant neoplasms of breast

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

C50.21 is a non-billable ICD-10-CM code header for malignant neoplasm of upper-inner quadrant of breast, female. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are C50.211 Malignant neoplasm of upper-inner quadrant of right female breast, C50.212 Malignant neoplasm of upper-inner quadrant of left female breast and C50.219 Malignant neoplasm of upper-inner quadrant of unspecified female breast. Its coding notes include a Use additional code instruction and 1 Excludes1 entry.

Guidelines tip

From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.

A primary malignancy code stays in use until treatment directed at that site is completed. After that, with no evidence of disease at the site, Z85 gives the former site.

Guidelines I.C.2.mCurrent malignancy versus personal history of malignancyRead the official text

Use additional code

Add the listed code as a secondary code, if known.

Inherited from C50 Malignant neoplasm of breast
  • code to identify estrogen, and other hormones and factors receptor status (Z17.-)

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Inherited from C50 Malignant neoplasm of breast

Includes

Further defines or gives examples of the content of the category.

Inherited from C50 Malignant neoplasm of breast
  • connective tissue of breast
  • Paget's disease of breast
  • Paget's disease of nipple

Notes

Also from chapter/block level (8 notes)
Inherited from Chapter 2 Neoplasms
  • Functional activity
  • All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
  • Morphology [Histology]
  • Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
  • Primary malignant neoplasms overlapping site boundaries
  • A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
  • Malignant neoplasm of ectopic tissue
  • Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).

More specific codes under C50.21 3