49180

Percutaneous Needle Biopsy of Abdominal or Retroperitoneal Mass

CPT 49180 describes a percutaneous needle biopsy of a mass located within the abdominal cavity or the retroperitoneal space. This procedure is a minimally invasive diagnostic technique used to obtain tissue samples for histological or cytological examination without the need for open surgical exploration. The retroperitoneal space is the anatomical area behind the abdominal cavity, housing organs such as the kidneys, adrenal glands, pancreas, and major vascular structures like the aorta and vena cava. The abdominal mass may involve the mesentery, omentum, or other non-organ specific soft tissues. During the procedure, the patient is typically positioned based on the location of the target lesion. Local anesthesia is administered to the skin and underlying soft tissues. Using real-time imaging guidance—such as computed tomography (CT), ultrasound, or fluoroscopy—the physician inserts a biopsy needle through a small skin nick. The needle is advanced through the abdominal wall into the target mass. The biopsy may be performed using a fine-needle aspiration (FNA) technique to obtain cells or, more commonly for this code, a core needle biopsy to obtain a cylinder of tissue that preserves the architectural structure of the lesion. Multiple passes may be required to ensure adequate diagnostic material. Once samples are retrieved, the needle is removed, and pressure is applied to the site to prevent hematoma formation. Imaging guidance is reported separately, as 49180 represents only the surgical component of the biopsy.

Clinical Indications

  • Investigation of an unexplained abdominal or retroperitoneal mass identified on imaging
  • Staging of known malignancies such as lymphoma or metastatic disease
  • Characterization of adrenal masses (e.g., distinguishing between adenoma and carcinoma)
  • Evaluation of retroperitoneal lymphadenopathy
  • Diagnosis of primary retroperitoneal tumors such as liposarcomas
  • Assessment of mesenteric or omental masses of unknown etiology

Procedure Steps

  1. The patient is positioned (supine, prone, or lateral) and the biopsy site is identified using imaging guidance.
  2. The skin is prepped with an antiseptic solution and draped in a sterile fashion.
  3. Local anesthetic (e.g., 1% lidocaine) is infiltrated into the skin and subcutaneous tissues down to the peritoneum or fascia.
  4. A small stab incision is made in the skin with a scalpel to facilitate needle entry.
  5. Under imaging guidance (CT or Ultrasound), a biopsy needle (typically 14-20 gauge) is advanced into the mass.
  6. Tissue samples are obtained using a spring-loaded biopsy gun or manual aspiration technique.
  7. The needle is withdrawn, and the specimen is placed in a fixative solution for pathology.
  8. Manual pressure is applied to the puncture site, followed by the application of a sterile dressing.
  9. The patient is monitored for post-procedural complications such as internal bleeding or organ injury.

Coding Guidelines

  • Do not report 49180 in conjunction with an open abdominal procedure at the same site.
  • Imaging guidance (e.g., 76942 for ultrasound, 77012 for CT, 77002 for fluoroscopy) should be reported separately.
  • If a fine needle aspiration (FNA) is performed instead of a core biopsy, use the FNA series (10004-10021) instead of 49180.
  • For biopsy of a specific organ within the abdomen, use the organ-specific biopsy code (e.g., 47000 for liver, 50200 for kidney) rather than 49180.
  • Modifier 51 may be applicable if multiple biopsies are performed at different sites during the same session, subject to payer-specific rules.
  • Pathology services (e.g., 88305) are reported separately by the pathologist.

Associated ICD-10 Codes