Malignant neoplasm of ovrlp sites of left female breast

This code signifies a primary malignant tumor affecting multiple contiguous or overlapping regions within the left female breast, where the point of origin cannot be assigned to a single specific anatomical site. This includes situations where a tumor spans across quadrants or involves both a quadrant and the central portion of the breast.

Apply this code when documentation clearly indicates a primary malignancy of the left breast that extends across or involves more than one distinct anatomical site, such as a tumor involving both the upper-outer and lower-outer quadrants. This code is appropriate when the medical record explicitly states "overlapping sites" or describes a tumor that defies localization to a single breast region.

• Do not use this code if the malignancy is clearly confined to a single quadrant or specific anatomical site; instead, use the appropriate C50.x12 code.
• Ensure the documentation specifies "left" breast; if the laterality is not documented, query the provider.
• This code is for primary malignancies only; for secondary or metastatic breast cancer, refer to codes in the C79 category.