Pathology/Lab Coding Alert

Follow diagnosis-code lead.

If you face a pathology report labeled “soft tissue mass,” you might have your coding work cut out for you.

“Soft tissue is a catch-all phrase that doesn’t tell you very much — so you have to look deeper at the gross and microscopic sections of the pathology report to figure out the proper code,” says Brenda Cox MT (ASCP), CPC, FHFMA, editor of Pathology Service Coding Handbook with the American Pathology Foundation in Laguna Beach, CA.

Examine the following four situations to zero in on how to choose the proper procedure and diagnosis codes for your soft-tissue cases.

Case 1: Follow Lipoma Diagnosis

The pathologist receives a specimen labeled “soft tissue mass, right forearm.” The pathology report describes dermis and subcutaneous tissue and fascia, with “mature adipocytes in an encapsulated mass.” The pathologist defines the specimen as a “lipoma.”

Dx: The correct diagnosis code for this specimen is D17.21 (Benign lipomatous neoplasm of skin and subcutaneous tissue of right arm)

“The lipoma diagnosis drives the procedure code choice for this case,” says R.M. Stainton Jr., MD, president of Doctors Anatomic Pathology Services in Jonesboro, Ark. You should always report a lipoma as 88304 (Level III - Surgical pathology, gross and microscopic examination … lipoma), regardless of the size, location or other qualifying descriptors in the report.

Another “soft tissue” specimen that falls under 88304 is material from a debridement procedure that goes deeper than the epidermis. CPT^® lists these specimens as 88304 (… debridement, Soft tissue).

Case 2: Save 88307 for Biopsy or Simple Excision

The pathologist received a “soft tissue mass” from a 32-year-old male patient’s neck near the cervical spine C3. The pathology report describes a 3 cm well-circumscribed tumor originating in the deep subcutaneous tissue. The microscopic description depicted consistent fibrous spindle cells with myxoid degeneration of the stroma. The pathologist diagnosed atypical fibrous histiocytoma of soft tissue.

Dx: The appropriate diagnosis code for this case is D48.1 (Neoplasm of uncertain behavior of connective and other soft tissue).

The pathology report affirms that this soft tissue mass was not a lipoma, and the specimen represented a simple excision of a well-circumscribed tumor. That means the most appropriate procedure code for this case is 88307 (Level V - Surgical pathology, gross and microscopic examination … Soft tissue mass [except lipoma] - biopsy/simple excision…).

Case 3: Turn Here For Soft Tissue ‘Other’

The surgeon submits contents of a nasal sinus surgery composed of mucous membrane and associated soft tissue for a patient with ongoing sinus problems. The pathologist finds no bony structures such as septum or turbinates in the specimen, but describes inflamed, ulcerated “soft tissue of the ethmoid sinus.” The final diagnosis is “chronic ethmoid sinusitis.”

Dx: You should use J32.2 (Chronic ethmoidal sinusitis) for the ICD-10 code in this case. Avoid J01.2 (Acute ethmoidal sinusitis), because the surgical note indicates a chronic sinus condition.

Code the pathologist’s work as 88305 (Level IV - Surgical pathology, gross and microscopic examination … Soft tissue, other than tumor/mass/lipoma/debridement …).

You chose this code by a process of elimination, according to Stainton, “because the soft tissue submitted is not a tumor, a mass, a lipoma, or a debridement specimen.”

Case 4: Know Where Sarcoma Stands

The surgeon submitted large mass from the patient’s left quadriceps that included the entire tumor with a surrounding layer of intact muscle.

The pathologist processed the specimen in four blocks, noting dense pleomorphic storiform cell types. Immunohistochemical (IHC) staining on selected slides from two blocks showed positive vimentin and p63 as well as CD99, but negative for CK-7 and CD68. The pathologist diagnosed myxofibrosarcoma (MFS).

Dx: You should assign ICD-10 code C49.22 (Malignant neoplasm of connective and soft tissue of left lower limb, including hip).

The primary service the pathologist performs in this case 88309 (Level VI - Surgical pathology, gross and microscopic examination … Soft tissue tumor, extensive resection …). Using this code doesn’t depend on the diagnosis of a malignant tumor, just that the pathologist judges the tumor -resection examination to be “extensive” for the site.

Don’t miss: This case features five special IHC stains that the pathologist uses to focus the diagnosis for this soft tissue tumor to MFS. Because the pathologist used five distinct IHC stains, you should code the work as follows:

• 88342, Immunohistochemistry or immunocytochemistry, per specimen; initial single antibody stain procedure
• +88341, … each additional single antibody stain procedure (List separately in addition to code for primary procedure) x 4 units.

Notice that the number of blocks is not relevant to how you should code the IHC stains, because the 88342 code family states, “per specimen.”