Podiatry Coding & Billing Alert

Lesion and margin measurements dictate your reimbursement -- find out why.

Sometimes the reports you receive from your physician/surgeon only leaves you confused on what codes to use in your claim. Resolve this dilemma by reading through the documentation with scrutinizing eyes, and you'd be able to determine the appropriate codes and areas for clarification in no time. Examine the following op note:

Preoperative diagnosis: Unknown soft tissue mass, left foot

Postoperative diagnosis: Unknown soft tissue mass, left foot

Operation: Excision of subcutaneous soft tissue mass, left foot Gross findings and procedure description:

Anesthesia: Local with IV sedation

Hemostasis: Pneumatic tourniquet at 250 mmHg x 18 minutes

Estimated blood loss: Less than 5 mL

Materials: Xeroform gauze and 3-0 Prolene

Post-op injections: 5 mL 0.5 percent Marcaine plain

Procedure: This patient was taken to the operating room and placed on the operating table in supine position. Following the introduction of intravenous sedation and regional local anesthesia, the left foot was prepped and draped in the usual sterile manner. At this time, two converging semi-elliptical incisions were created in the plantar aspect of this mass on the left foot and deepened down to the level of the subcutaneous tissue. The encompassing skin wedge and soft tissue mass were meticulously dissected free with blunt and sharp scissors. It was noted to go into the fat tissue. It was a hard fibrotic mass. The mass and skin were excised in toto. We further explored the area. No other suspicious-appearing lesion was noted. The wound was flushed copiously. We then closed the wound. Post-op injection and Xeroform gauze were applied. A post-op dressing was applied.

Surgical Pathology Report:

Diagnosis: Foot mass, left, granuloma dermatitis with polarizable foreign bodies (possibly silica), excised. Subcutaneous fat is present at the base of the excision. Received is an elliptical portion of tan tissue measuring 26 x 9 x 12 mm. A centrally placed ulcerated lesion measures 3 x 3 mm. No orientation identified. The surgical margins are inked. No masses identified grossly. Sectioned and totally submitted.

You think you know how to tackle this lesion excision case? Spot what needs improvement by following this 3-step guideline.

1. Point to the Correct ICD-9 Clue

If the op note and surgical pathology report describes two different diagnoses, you should make the pathology report the basis of your ICD-9 code.

Warning: The pathology report is a must, or else you'd have no way of knowing what type of mass the surgeon removed.

The op note presented above reveals the diagnosis: "Unknown soft tissue mass, left foot," while the pathology report details another one: "Foot mass, left, granuloma dermatitis with polarizable foreign bodies (possibly silica)."

Code it: You should assign 709.4 (Foreign body granuloma of skin and subcutaneous tissue) for the diagnosis, says Shelly Ghrist, CPC, assistant manager of Wolf Creek Medical Associates in Grove City, Pa.

2. Pinpoint the CPT Based on Lesion and Margin Sizes

The provider has the responsibility of measuring the lesion with margins prior to excision of the lesion. You need these measurements to be able to come up with the appropriate code. For instance, the case study's op note didn't include the lesion size as it should have; only the pathology report did. Neither reports the margin measurements.

Purpose: Both lesion and margin size matter because according to CPT guidelines, "Code selection is determined by measuring the greatest diameter of the apparent lesion plus the margin required for complete excision (lesion diameter plus the most narrow margins required equals the excised diameter). The margins refer to the narrowest margin required to adequately excise the lesion, based on the physician's judgment."

What to do: You should look for the measurements that the provider takes before excising the lesion. But remember, lesions shrink when the pathologist analyzes them, which means the 3 mm x 3 mm in the sample path report is probably smaller than the lesion's actual size.

3. Be Aware of the Profits You Might Be Missing

Since the case study didn't have actual measurements, and assuming the surgeon couldn't provide one, you might have to code the excision conservatively by using  the 3-mm x 3-mm lesion measurement. A 3-mm diameter converts to about 0.3 cm, which means you should report 11420 (Excision, benign lesion including margins, except skin tag [unless listed elsewhere], scalp, neck, hands, feet, genitalia; excised diameter 0.5 cm or less).

Smart move: Take 11420's RVU, which is 2.99, and compare it with the next-level code's RVU (11421, ... excised diameter 0.6 to 1.0 cm), which is 3.89. If you multiplied them by the conversion factor of 36.8791, you'd find that reporting 11420 would pay about $110.25, and 11421 about $143.44 -- a difference of about $33.19. Imagine how much you'd be missing if you didn't have the exact lesion or margin measurements. Make sure you run after your surgeon to clarify this information.