Pathology/Lab Coding Alert

Question: The pathologist interprets two FNA specimens -- one from a nodule in the right thyroid lobe, and one from the left thyroid lobe. Examining the aspirates involves concentrated smears from both FNA sites, and one cell block from the right lobe and two cell blocks from the left. How should we code the case?

Georgia Subscriber

Answer: This case involves multiple procedures, and you should code some of them separately. You must ensure that the pathology report documents each individual service.

Because the two FNA specimens are from different sites (left and right thyroid lobe), you should report two units of 88173 (Cytopathology, evaluation of fine needle aspirate; interpretation and report).

You should not separately report additional smear preparations, such as concentrated smears, using an additional code, even if that code appropriately describes the work your lab performed -- such as 88108 (Cytopathology, concentration technique, smears and interpretation [e.g., Saccomanno technique]) or 88112 (Cytopathology, selective cellular enhancement technique with interpretation [e.g., liquid based slide preparation method], except cervical or vaginal).

Here's why: An FNA specimen is a source distinct from any other non-gyn cytology sources, such as "fluids, washings, or brushings" described by codes such as 88104 (Cytopathology, fluids, washings or brushings, except cervical or vaginal; smears with interpretation). Additionally, Medicare and some other payers consider a second cytology preparation on a specimen to be a duplicate service -- except for cell block.

That means you can code cell block(s) separately. In this case, you should report two units of 88305 (Level IV - Surgical pathology, gross and microscopic examination, cell block, any source).

Why two? The reason you should report two units -- not one or three -- is that the unit of service for the cell block is the primary specimen, according to the AMA. In this case, you have two primary specimens -- two distinct FNA specimens from two different body sites. So you should report 88305 for the single cell block from the right thyroid lobe FNA, and 88305 for the two cell blocks from the left thyroid lobe FNA.

Bottom line: The final coding for the case is 88173 x 2; 88305 x 2. You shouldn't need a modifier to bill these services together.