Pathology/Lab Coding Alert

Question: Our lab received a toenail biopsy for a fungal exam. We performed a PAS stain rather than a culture and positively identified a fungal infection consistent with onychomycosis. Should we code for the stain only?

New Jersey Subscriber

Answer: The correct code for the fungal stain on the toenail specimen is +88312 (Special stains [List separately in addition to code for primary service];Group I for microorganisms [e.g., Gridley, acid fast, methenamine silver], each).

Because +88312 is an add-on code, however, you have to bill it in addition to the primary service. You don't mention a microscopic exam other than the stain for the toenail specimen.

Solution: When the lab accessions the toenail biopsy specimen, at least a gross pathology exam should occur. As long as you have documentation of a pathology gross exam to confirm the specimen, you should report 88300 (Level I -- Surgical pathology, gross examination only). Then you can report +88312 in addition to the 88300 primary-service code.

Watch for more: If the toenail has soft tissue attached and the pathologist examines hematoxylin and eosin (H & E) stained slides in addition to the special fungal stain, you should report a gross and microscopic pathology exam. Because -toenail- is not a listed specimen, you should select the surgical pathology code based on the level of work the pathologist performs relative to other listed specimens, such as 88302 (Level II -- Surgical pathology, gross and microscopic examination) for a confirmatory identification exam, or 88304 (Level III -- Surgical pathology, gross and microscopic examination) for work comparable to a debridement.