Malignant neoplasm of overlapping sites of left male breast

This code signifies a primary cancerous tumor affecting multiple contiguous or overlapping regions within the left male breast, where the exact point of origin cannot be determined. This typically involves a malignancy that has spread across different quadrants or anatomical subdivisions of the breast, making a single site classification impossible.

Use this code when documentation explicitly states a malignant neoplasm involving overlapping sites of the left male breast. This is appropriate when the tumor's boundaries cross multiple defined anatomical regions (e.g., upper-outer and lower-outer quadrants) and the pathology report confirms malignancy.

• Ensure the documentation specifies "overlapping sites" or "multiple sites" within the left male breast, not just a single, large tumor.
• Distinguish from C50.922 (Malignant neoplasm of unspecified site of left male breast), which is used when the specific site within the breast is unknown.
• Always confirm laterality (left) and patient's sex (male) are clearly documented.