Pathology/Lab Coding Alert

Question: Our pathologist receives a skin specimen labeled "atypical growth of left ear." Upon examination, the pathologist diagnoses the specimen as an epidermal inclusion cyst. How should we code this?

California Subscriber

Answer: You should assign the ICD-9 code based on the most specific diagnosis available. In this case, you have the pathologist's final diagnosis, so you should code the condition as an epidermal inclusion cyst (706.2, Sebaceous cyst). You should not code according to the original specimen label (239.2, Neoplasms of unspecified nature; bone, soft tissue, and skin).

The difference in diagnosis also impacts the procedure code selection in this case. You should report the pathologist's work as 88304 (Level III -- Surgical pathology, gross and microscopic examination; skin -- cyst/tag/debridement). Had the final diagnosis actually been a skin neoplasm, you would report the pathologist's service as 88305 (Level IV -- Surgical pathology, gross and microscopic examination; skin, other than cyst/tag/debridement/plastic repair).