Ultrasound-guided needle biopsy in children
Medical editor Heidi Glosli MD
Oncologist
Oslo University HospitalGeneral
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.
Indication
- Ambiguous lesions detected with radiological testing.
Goal
- Confirm or rule out malignant histology of suspect lesions.
Equipment
Biopsy equipment
Preparation
- 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.
Implementation
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.
- Aspirate.
- 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.
Follow-up
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The child will often remain in the hospital until the following day.
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Depending on the location of the biopsy, bleeding can sometimes occur after taking the specimen.
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For pain or bleeding, the patient must be observed at the ward or intensive unit depending on the severity. Necessary measures must be initiated.
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After a biopsy of parenchymatous organs, an ultrasound examination is made, and hemoglobin is checked possibly the following day.