How To Use CPT Code 88366

CPT 88366 describes the procedure for in situ hybridization (ISH) using a multiplex probe stain on a single patient specimen. This article will cover the description, procedure, qualifying circumstances, appropriate usage, documentation requirements, billing guidelines, historical information, similar codes and billing examples.

1. What is CPT Code 88366?

CPT 88366 can be used to describe the procedure of in situ hybridization (ISH) using a multiplex probe stain on a single patient specimen. This code is used when a lab analyst applies a single ISH multiplex probe stain on a slide or slides prepared from a single patient specimen, such as tumor tissue. A qualified provider, typically a pathologist, then interprets the stained slides to provide a pathologic diagnosis.

2. Official Description

The official description of CPT code 88366 is: ‘In situ hybridization (eg, FISH), per specimen; each multiplex probe stain procedure. Notes: (Do not report 88365, 88366 in conjunction with 88367, 88368, 88374, 88377 for the same probe)’

3. Procedure

1. The lab analyst prepares stained slides using a specialized stain, including a DNA or RNA probe that selectively attaches to a target segment of DNA or RNA in the patient tissue.
2. The lab analyst cuts and mounts the patient tissue onto slides and adds reagents to prepare the slides to receive the stain.
3. The lab analyst applies the ISH multiplex probe stain, which includes multiple probes to detect multiple targets, on the prepared slides.
4. The pathologist qualitatively interprets the stained slides under a microscope to reach a pathologic diagnosis.
5. The pathologist prepares a report for the ordering clinician based on the interpretation of the stained slides.

4. Qualifying circumstances

CPT 88366 is used when a lab analyst applies a single ISH multiplex probe stain on a slide or slides prepared from a single patient specimen. This procedure is typically performed to aid in the diagnosis of certain cancers, as it allows the provider to detect and localize a gene of interest in the specimen. It is important to note that CPT 88366 should not be reported in conjunction with CPT codes 88367, 88368, 88374, or 88377 for the same probe.

5. When to use CPT code 88366

CPT code 88366 should be used when a lab analyst performs the ISH procedure using a multiplex probe stain on a single patient specimen. This code should be reported once per specimen, regardless of the number of blocks or stained slides prepared by the lab analyst. It is important to use this code only for qualitative ISH and to use other codes in the range 88367 to 88377 for quantitative or semiquantitative ISH.

6. Documentation requirements

To support a claim for CPT 88366, the documentation should include:

• Details of the patient specimen and the need for ISH
• Specific information about the ISH multiplex probe stain used
• Date and time of the procedure
• Qualitative interpretation of the stained slides by the pathologist
• Pathologic diagnosis and any additional findings
• Signature of the qualified provider performing the interpretation

7. Billing guidelines

When billing for CPT 88366, ensure that the procedure is performed on a single patient specimen using a multiplex probe stain. Do not report CPT 88366 in conjunction with CPT codes 88367, 88368, 88374, or 88377 for the same probe. If billing for only the technical work performed by the lab analyst, append modifier TC (Technical Component) to the code. If billing for only the professional work performed by the pathologist, append modifier 26 (Professional Component) to the code.

8. Historical information

CPT 88366 was added to the Current Procedural Terminology system on January 1, 2015. There have been no updates to the code since its addition.

9. Examples

1. A lab analyst applies a multiplex ISH probe stain on slides prepared from a tumor tissue specimen, and a pathologist interprets the stained slides to diagnose breast cancer.
2. A lab analyst performs ISH using a multiplex probe stain on slides prepared from a cervical tissue specimen, and a pathologist interprets the stained slides to diagnose cervical cancer.
3. A lab analyst applies a multiplex ISH probe stain on slides prepared from a lung tissue specimen, and a pathologist interprets the stained slides to diagnose lung cancer.
4. A lab analyst performs ISH using a multiplex probe stain on slides prepared from a prostate tissue specimen, and a pathologist interprets the stained slides to diagnose prostate cancer.
5. A lab analyst applies a multiplex ISH probe stain on slides prepared from a liver tissue specimen, and a pathologist interprets the stained slides to diagnose liver cancer.
6. A lab analyst performs ISH using a multiplex probe stain on slides prepared from a colon tissue specimen, and a pathologist interprets the stained slides to diagnose colon cancer.
7. A lab analyst applies a multiplex ISH probe stain on slides prepared from a skin tissue specimen, and a pathologist interprets the stained slides to diagnose melanoma.
8. A lab analyst performs ISH using a multiplex probe stain on slides prepared from a bladder tissue specimen, and a pathologist interprets the stained slides to diagnose bladder cancer.