Pathology/Lab Coding Alert

Question: The pathologist examined a toenail biopsy and also performed a PAS stain. The pathologist reported the biopsy positive for fungal spores and hyphae. What are the correct diagnosis and procedure codes?

Illinois Subscriber

Answer: Toenail is not a listed specimen for surgical pathology, so you'll need to select the service level based on the comparable physician work. This would probably be 88304 (Level III -- Surgical pathology, gross and microscopic examination ...), similar to listed specimens "skin - cyst/tag/debridement," or "soft tissue, debridement."

Caution: Sometimes pathologists will perform a gross-only nail exam before proceeding with the PAS stain for fungus. If the pathology report doesn't document microscopic exam, you should list 88300 (Level I -- Surgical pathology, gross examination only) instead of 88304

In addition to the biopsy procedure code, you should also report the PAS stain using 88312 (Special stain including interpretation and report; Group I for microorganisms [e.g., acid fast, methenamine silver]).

Diagnosis: The correct ICD-9 code for the positive fungal findings in the toenail biopsy is 110.1 (Dermatophytosis of nail).