Neoplasm of unspecified behavior of left kidney

This code signifies the presence of an abnormal growth or mass within the left kidney whose biological behavior (i.e., whether it is benign, malignant, or uncertain) has not yet been definitively determined through pathological examination. It indicates a kidney lesion requiring further investigation to establish its nature.

Use this code when imaging studies (e.g., CT, MRI, ultrasound) identify a mass or lesion in the left kidney, and biopsy or surgical pathology results are pending or inconclusive regarding its malignancy. It is appropriate for initial presentation of a renal mass before a definitive diagnosis of benign or malignant neoplasm can be made.

• Do not use this code if pathology definitively identifies the neoplasm as benign (D30.01) or malignant (C64.2).
• Always sequence this code as the primary diagnosis when the renal mass is the reason for the encounter and its behavior is unknown.
• Ensure documentation clearly specifies the left kidney; otherwise, use D49.519 for unspecified side.