Ultrasound-guided needle biopsy in childrenMedical editor Heidi Glosli MD
Oslo University Hospital
Ultrasound-guided biopsy is sometimes used to diagnose possible pathology in suspect lesions/changes. Fine-needle biopsy is always used initially. The cell smear is immediately stained and assessed by a cytologist. In most cases, a histological pistol biopsy is also performed (Tru-Cut®). It is often necessary to wait 2-6 days for the result before starting treatment.
- Ambiguous lesions detected with radiological testing.
- Confirm or rule out malignant histology of suspect lesions.
- For ultrasound-guided puncture under general anesthesia, the child must fast for the last 4-6 hours before the test.
- Depending on the localization and accessibility of the lesion, precautions should be taken regarding bleeding parameters (hemoglobin, thrombocytes, INR, and Cephotest).
- The child and parents are informed about the procedure.
- The biopsy is performed under general anesthesia.
Ultrasound-guided biopsy is performed under general and local anesthesia depending on the depth and localization.
- Localize the lesion with the ultrasound probe.
- Determine the best point and direction for puncture.
- Mark the puncture point so the canal is easy to remove later.
- Wash the puncture point with colored chlorhexidine 1 mg/ml.
- Allow the skin to dry.
- Inject local anesthesia if necessary.
- Puncture the spinal needle quickly through the skin.
- Guide the needle through the peritoneum using ultrasound and further into the lesion.
- Remove the stylet.
- When the material is visible at the top, the needle is retracted.
- Deposit the material on a slide.
Smear for cytology
- Smear the material on to the slide.
- Allow the material to air dry.
- Staining: fixing fluid with methanol + Hemacolor + rinsing in water
- 5 dips in fixing fluid. Allow the solution to drop onto paper.
- 3 dips in staining solution 1.
- 6 dips in staining solution 2. Allow the solution to drop onto paper.
- Rinse in 2 baths of clean water.
- Examine the specimen under the microscope with 10x or 20x objective.
The microscopic assessment of the cell material should be performed by a cytologist to determine if there is adequate tissue or if there should be supplementary testing.
Histological biopsy (pistol biopsy)
- Inject the local anesthesia in the skin.
- Make a small incision in the skin.
- Insert the biopsy needle on to the lesion and gently into it, depending on the size of the lesion and the type of tissue in front and behind the lesion.
- Trigger the pistol to retrieve the material.
- Retract the needle and open it.
- Place the piece of tissue onto a slide with medium, for example formalin or 0.9% NaCl.
The child will often remain in the hospital until the following day.
Depending on the location of the biopsy, bleeding can sometimes occur after taking the specimen.
For pain or bleeding, the patient must be observed at the ward or intensive unit depending on the severity. Necessary measures must be initiated.
After a biopsy of parenchymatous organs, an ultrasound examination is made, and hemoglobin is checked possibly the following day.