Question: International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) code N63 (unspecified breast lump) requires specification of the quadrant of the lump site. Radiology report states, “12 o’clock right breast mass.” How do you code for a 3, 6, 9, and 12 o'clock breast mass/lesion since there are no "other specified site" or “unspecified quadrant” codes?
Answer: There is no ideal method for defining the quadrant of breast lumps at the 3, 6, 9, and 12 o'clock positions. The ACR thus recommends that radiologists select the nearest quadrant to the abnormality while being as consistent as possible in their practice.
For Medicare patients, however, the Centers for Medicare and Medicaid Services (CMS) provided guidance for coding overlapping quadrants in the National Coverage Determination (NCD) for Mammograms. The NCD states, “Dual dx codes depicting specific quadrants can be reported instead of unspecified quadrants if found more appropriate by provider.” Given this guidance, a 12 o’clock right breast mass can be reported as ICD-10 code N63.15, Unspecified lump in right breast, overlapping quadrants, or as dual ICD-10 codes for overlapping quadrants, N63.11, Unspecified lump in the right breast, upper outer quadrant, and N63.12, Unspecified lump in the right breast, upper inner quadrant.