Pathology/Lab Coding Alert

Number of physicians should determine your code choice

A pathologist diagnoses a cancerous skin lesion removed by a dermatologist and reports the need for further excision during the same surgical session. If you would code this procedure as Mohs surgery, you're putting your physicians at risk for fraud charges.

Know where to draw the line: Mohs surgery is one of the most effective treatments for skin cancer. But successful coding requires knowing when you must use different surgery and pathology codes, when you're allowed to use Mohs codes, and how to report each stage when Mohs codes are appropriate. Let the answers to these frequently asked questions guide you to ethical Mohs coding. Just One Physician Performs Mohs Q: When should I use the Mohs codes?

A: The Mohs chemosurgery codes (17304-17310, Chemosurgery [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 complete histopathologic preparation including the first routine stain [e.g., hematoxylin and eosin, toluidine blue]...) are unique because they are "the only CPT codes that describe procedures that involve surgery and pathology services performed together by the same surgeon or pathologist," the July 2004 CPT Assistant states.

In Mohs surgery, "the physician works as a surgeon and a pathologist," says Margarida Cabral, CPC, coder for the Lahey Clinic in Burlington, Mass. Report these codes only if the physician both excises the tissue and examines the excised tissue to locate remaining tumors, she says. If a dermatologist excises the tissue and a pathologist examines it, you should report their services with entirely different codes.

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.

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: ICD9 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).

Lesson learned: Don't use Mohs codes if two separate physicians perform the skin excision and examination. Use surgical codes when a dermatologist excises a skin lesion and separate pathology codes when a pathologist examines [...]