Unspecified lump in breast (N63) ICD-10-CM

About the N63 Code Range

The ICD-10 code N63 and its subcodes are used to classify an unspecified lump in the breast, covering various locations such as unspecified breast, right or left breast, specific quadrants, axillary tail, and subareolar areas. These codes help document nonmalignant breast lumps when the cause or exact diagnosis is not specified.

These codes include N63.0 for lumps in an unspecified breast and detailed subcodes for lumps located in the right breast (N63.1 series) and left breast (N63.2 series), broken down further by specific breast quadrants—such as upper outer, upper inner, lower outer, and lower inner quadrants. For example, N63.11 represents an unspecified lump in the upper outer quadrant of the right breast, also known as a “lump in upper outer quadrant of right breast.” Additionally, lumps in the axillary tail of the breast and subareolar areas have their respective codes, like N63.31 and N63.41. Terms like “breast lump,” “mass of nipple of breast,” “soft lump of breast,” or “chest swelling” commonly correspond to these ICD-10 codes. These codes are crucial for medical coders to accurately record and track cases where a breast lump is noted but not yet definitively diagnosed or specified as benign or malignant.