Malignant inflammatory neoplasm of left breast

This code signifies a rare and aggressive form of breast cancer characterized by rapid onset, diffuse erythema, edema, and warmth of the skin, often without a palpable mass. It is a clinical diagnosis, as the inflammatory signs are caused by malignant cells blocking lymphatic drainage in the dermal capillaries.

Apply this code when documentation clearly states "inflammatory breast cancer" affecting the left breast. This diagnosis is typically made based on clinical presentation and confirmed by biopsy showing dermal lymphatic invasion by carcinoma cells.

• Ensure the documentation explicitly states "inflammatory" to differentiate from other breast malignancies.
• Do not use this code for simple mastitis or other non-malignant inflammatory conditions of the breast.
• Always sequence this code as the primary diagnosis when it is the reason for the encounter.