Info

Biopsy

The use and effectiveness of image guided percutaneous biopsy, either by fine needle aspiration (FNA) or core needle biopsy (CNB), has been well documented in adult radiology. In children there seems to be some reluctance amongst clinicians and pathologists to use this technique and therefore surgical excision biopsies are frequently obtained. The obvious advantage of percutaneous over surgical excision biopsies is that it can be done under local anaesthesia and mild sedation, although in some cases deep sedation will still be necessary. In the adult population percutaneous biopsies of soft tissue masses have almost completely replaced surgical excision biopsies. Indications for performing a biopsy are obtaining pathologic information on a mass which can modify patient treatment, confirmation of metastases or in case of diagnosis of hepatic disease (Norman 2001; Hoffer 1997).

The advantage of CNB over FNA is the fact that a larger specimen is obtained which makes it possible to perform histological studies, showing not only the absence or presence of malignant cells but also the architectural composition of the mass (Cheung et al. 2000). Therefore, whenever possible, CNB should be the biopsy method of choice (Fig. 7.13). The relative drawback of CNB over FNA is that it is somewhat more invasive. An advantage of FNA is that the procedure is relatively easy to perform and that the material can be screened on-site. In our clinic we always have a pathologist in the room for immediate assessment of the quality of the aspirated material. The choice for FNA depends largely on the availability of an experienced cytologist and the type of lesion to be biopsied. In particular, more deeply located lesions, such as pancreatic lesions, will be

Fig. 7.13. A 1-year-old boy with a solid tumour arising from the adrenal gland. Biopsy was performed to confirm the diagnosis of neuroblastoma and to obtain specimen for genetic marker studies. The biopsy was done using freehand technique, the arrow delineates the biopsy needle. S, spleen; M, mass more approachable for FNA than CNB, for example using a transgastric approach.

For CNB one can choose for either a cutting-edge or so called 'tru-cut' needle with or without an automated biopsy device. Numerous variants of both devices are on the market, with personal experience usually guiding the choice for a specific device. The same applies for the use of a biopsy adaptor attached to the head of the ultrasound probe, which guides the needle, or the use of freehand technique. When the biopsy adaptor is used the needle follows the path that is overlain over the ultrasound image by special biopsy software, thus allowing for a highly accurate biopsy. A much-used technique is working coaxially. A needle is advanced into or near to the lesion, the biopsy needle is inserted and biopsies are taken. Using this technique multiple passes are easily possible with a low risk of spill and thus avoiding potential complications of the procedure. A second advantage is that due to the coaxial needle configuration haemostatic material can be deposited into the needle tract. This has been reported to be a very effective technique for reducing the risk of CNB-induced haemorrhage, especially in liver lesions (Kaye and Towbin 2002; Hoffer 2000).

Several studies into the effectiveness of FNA and CNB in children have been published (Cheung et al. 2000; Hoffer 2000; Guo et al. 2002; Lieberman et al. 2003; Muraca et al. 2001; Nobili et al. 2003; Saarinen et al. 1991; Scheimann et al. 2000;

Fig. 7.14. a A 17-year-old boy who was involved in a motor vehicle accident. At presentation at the emergency department, ultrasound imaging showed free fluid surrounding the left kidney. Computed tomography revealed a left renal laceration. The ensuing selective renal angiography (arrow denotes the angiography catheter) clearly demonstrates contrast extravasation (curved arrow). b After embolization with multiple coils no contrast extravasation was seen thus preserving renal function

Fig. 7.14. a A 17-year-old boy who was involved in a motor vehicle accident. At presentation at the emergency department, ultrasound imaging showed free fluid surrounding the left kidney. Computed tomography revealed a left renal laceration. The ensuing selective renal angiography (arrow denotes the angiography catheter) clearly demonstrates contrast extravasation (curved arrow). b After embolization with multiple coils no contrast extravasation was seen thus preserving renal function b a

Sklam-Levy et al. 2001; Yu et al. 2001; RoebucK 2004). The diagnostic yield ranged from 83% to 100%. The rate of complications depends largely on the biopsy site, with the highest number of complications found in hepatic biopsies (up to 14% post-procedural haemorrhage).

Although one would expect a significant difference in complication rates of blind versus image guided biopsies, relatively few studies have been performed to demonstrate this. Nobili et al. (2003) reported a retrospective analysis on 140 biopsies (64 blind versus 76 ultrasound guided), in which 95% of the blind biopsies and 100% of the ultrasound guided biopsies were of diagnostic quality. Moreover, in the blind biopsy population three patients developed significant haemorrhage versus none in the ultrasound guided population.

A special approach to biopsies is that for liver biopsy in children with a coagulopathy or a significant amount of ascites. If in this category of patients a liver biopsy is needed, a transjugular approach should be used. The right jugular vein is punctured under ultrasound guidance. Using guidewires and catheters the middle or right hepatic vein is catheter-ised. Subsequently a stainless steel trocar is placed over the guidewire. Up to this stage the procedure is in effect identical to TIPS. Using a spring-loaded transjugular biopsy needle biopsies of hepatic tissue can be obtained. Drawbacks of the transjugular approach are the use of a more invasive technique, higher costs and smaller (18 gauge) histological samples (Kaye and Towbin 2002; Kaye et al. 2000b). In a large retrospective study in adults by Smith et al. (2003) tissue diagnosis was possible in 98% of cases using a 18 gauge biopsy needle (Quick-Core, Cook, Bloomington, IN) (Smith et al. 2003). There was an overall 2.4% complication rate; one patient died as a result of haemorrhage; however, in this case the family's request to withhold invasive treatment was honoured.

Was this article helpful?

0 0
Constipation Prescription

Constipation Prescription

Did you ever think feeling angry and irritable could be a symptom of constipation? A horrible fullness and pressing sharp pains against the bladders can’t help but affect your mood. Sometimes you just want everyone to leave you alone and sleep to escape the pain. It is virtually impossible to be constipated and keep a sunny disposition. Follow the steps in this guide to alleviate constipation and lead a happier healthy life.

Get My Free Ebook


Post a comment