Related Terms: FNA biopsy; FNA cytology; needle biopsy service.
Test Includes: Interpretation of smears and/or cell block material by pathologist. Biopsy of palpable lesions by pathologist on call.
Availability: Mon–Fri 08:00–17:00, Sat, 08:00–12:00; Pathologist on call at all times for consultation. Immediate on-site smear preparation, adequacy assessment, and needle biopsy service by cytopathologist available on campus. Off campus physicians may send patients with palpable masses to laboratory for needle biopsy by cytopathologist — call pathology for instructions.
Special Instructions: Specify clinical differential diagnosis and pertinent past history. Label slides with patient name. Label slide holder with exact body site and patient's name. Tissue fragments may be submitted in formalin for cell block preparations. Aspirated cystic fluid may be submitted in capped syringe (without needle) or placed in a dry container.
- Consult with cytopathologist for detailed instructions on obtaining FNA specimen. Clean skin overlying the mass with alcohol wipe. A small amount of local anesthesia may aid patient comfort. Localize mass by palpation or imaging device. Use 23- to 26-gauge needle to collect sample by aspiration or non-aspiration technique. Place a drop of aspirated material in middle of glass slide. Place an inverted slide on top of the first slide and press the slides together to spread the material. Slide the slides apart and fix slide immediately if applicable. Excess sample material may be rinsed in formalin for cell block preparation. If lymphoma is suspected, the sample from at least one pass should be rinsed in RPMI solution for flow cytometry.
- Label frosted slides with patient's name. Repeat twice for a total of three samples. Label slide container with type of specimen and patient's name.
Analytic Time: 1–2 days.
Specimen: At least one air-dried or fixed slide (in 95% alcohol or spray fixed). Air-dried smears are especially preferred for lymph nodes and salivary gland biopsies. Fixed slides are preferred for thyroid FNA.
Causes for Rejection: Unlabeled specimen. Insufficient demographic or clinical information for processing.
Interpretation: Results interpreted by cytopathologists. Cell block preparation may permit special studies and facilitate more acute diagnosis.
Limitations: Adequate sampling of the mass lesion is usually critical for diagnosis. Obscuring blood, necrotic material, or overly thick material on the slide may compromise diagnosis. Lesions with densely fibrous stroma, low cellularity, or cystic neoplasms may be difficult to diagnose with needle biopsy.