Practice Management Alert

Tip: Don't bill path exam with revised Mohs codes 

Physicians, most commonly dermatologists, use  Mohs micrographic surgery to remove complex or ill-defined skin cancer with histologic examination of 100 percent of the surgical margins. In this way, the physician can be sure to remove the entire cancer without sacrificing excess tissue at the margins.

CPT revised the Mohs codes in 2007, as follows:

- 17311 -- Mohs micrographic technique, including removal of all gross tumor, surgical excision of tissue specimens, mapping, color coding of specimens, microscopic examination of specimens by the surgeon, and histopathologic preparation including routine stain(s) (e.g., hematoxylin and eosin, toluidine blue), head, neck, hands, feet, genitalia or any location with surgery directly involving muscle, cartilage, bone, tendon, major nerves or vessels; first stage, up to 5 tissue blocks.

- +17312 -- ... each additional stage after the first stage, up to 5 tissue blocks (list separately in addition to code for primary procedure) (Use 17312 with 17311 only.)

- 17313 -- Mohs micrographic technique, including removal of all gross tumor, surgical excision of tissue specimens, mapping, color coding of specimens, microscopic examination of specimens by the surgeon, and histopathologic preparation including routine stain(s) (e.g., hematoxylin and eosin, toluidine blue), of the trunk, arms or legs; first stage, up to 5 tissue blocks

- +17314 -- ... each additional stage after the first stage, up to 5 tissue blocks (list separately in addition to code for primary procedure)  (Use 17314 with 17313 only.)

- +17315 -- Mohs micrographic technique, including removal of all gross tumor, surgical excision of tissue specimens, mapping, color coding of specimens, microscopic examination of specimens by the surgeon, and histopathologic preparation including routine stain(s) (e.g., hematoxylin and eosin, toluidine blue), each additional block after the first 5 tissue blocks, any stage (list separately in addition to code for primary procedure) (Use 17315 with 17311-17314.)

Mohs Means One Physician Only

An important requirement: You should report 17311-17315 only if the physician both excises the tissue and examines the excised tissue to locate remaining suspicious cells, says Brett Coldiron, MD, a dermatologist and clinical assistant professor of dermatology at the University of Cincinnati. Mohs microsurgery -requires a single physician to act in two integrated but separate and distinct capacities: surgeon and pathologist,- according to CPT.
 
-The Mohs technique has always required the provider to act as both the surgeon and the pathologist. This has not changed from the old codes 17304-17310,- says Barbara Beran, RN, CMM, CPC, practice administrator for Heartland Dermatology and Skin Care Center in Hays, Saline and Great Bend, Kan.

Example: A dermatologist removes a skin lesion 0.8 cm in diameter and sends the specimen to a pathologist for a consultation during surgery. The pathologist fresh-freezes the tissue, processing it in two tissue blocks, and examines the margins microscopically, marking the location of any remaining tumor on the surgical wound map. The pathologist later examines permanent sections to provide a definitive diagnosis.

Caution: This case does not involve a Mohs procedure. Rather, it involves a dermatologist's surgical service (11641, Excision, malignant lesion including margins, face, ears, eyelids, nose, lips; excised diameter 0.6 to 1.0 cm) and a pathologist's consultation service: 88331 (Pathology consultation during surgery; first tissue block, with frozen section[s], single specimen) and 88332 for the second block (... each additional tissue block with frozen section[s]). The pathologist also performs a surgical pathology service: 88305 (Level IV -- Surgical pathology, gross and microscopic examination, skin, other than cyst/tag/debridement/plastic repair).

How it works: In a procedure using the Mohs codes appropriately, the dermatologist removes a skin lesion and freezes and examines the specimen. Upon examination, he sees there are malignant squamous cells in the margins of the specimen.

The dermatologist then returns to the patient and excises to a deeper level. The specimen(s) from this excision are again frozen and examined. This process continues until the margins of the specimen(s) are clear of any suspicious cells.

Warning: Never list a pathology exam code in addition to the surgical Mohs code for the same service. However, -this does not exclude billing a diagnostic frozen section (biopsy code and 88331 with 59) prior to the Mohs surgery to determine if the lesion is malignant, or to establish the diagnosis if the pathology report is over 90 days old or cannot be located,- Coldiron says. CPT does allow separate reporting of 88314 with modifier 59 (Distinct procedural service) for -nonroutine histochemical stain on frozen tissue,- however.

Pay Attention to Location

When reporting Mohs procedures, the area from which the physician performs the excisions and the -depth of the invasion of the tumor- determine the codes you will use, Coldiron says. For areas of the head, neck, hands, feet, genitalia -or any location with surgery directly involving muscle, cartilage, bone, tendon, major nerves or vessels,- you should turn to 17311 and 17312. For all other areas, you should report 17313 and 17314, Beran says.

You may report add-on code 17315 for -each additional block after the first 5 tissue blocks, any stage,- regardless of location.

Next step: In addition to location, you must have two additional pieces of information to select the correct Mohs surgery codes:

- How many layers (stages) of each lesion margin the physician excised

- How many pieces (tissue blocks) the physician divided each layer into.

Remember: If the physician performs Mohs on four separate lesion sites, use the Mohs codes once per lesion.