Fine-needle aspiration techniques for biopsy of deep-seated impalpable targets: a primer for radiologists

Techniques, Safety and Accuracy of Sampling of Renal Tumors by Fine Needle Aspiration and Core Biopsy

PURPOSE

The incidence of renal cell carcinoma is increasing worldwide and there are new treatments for localized as well as metastatic tumors. The traditional role for percutaneous biopsy of renal masses has been limited, and so there is little general experience. There have been concerns about safety and accuracy. This review provides an update on the current techniques, indications and accuracy of needle biopsy of renal tumors.

MATERIALS AND METHODS

PubMed and MEDLINE were searched for English language reports of percutaneous needle core biopsy and fine needle aspiration of renal tumors that were published from 1977 to 2006.

RESULTS

With the development of new biopsy techniques and wider experience with percutaneous probe ablation therapies the risk of tumor seeding appears negligible. Significant bleeding is unusual and almost always self-limiting. At centers with expertise needle core biopsy with or without fine needle aspiration appears to provide adequate specimens for an accurate diagnosis in more than 90% of renal masses.

CONCLUSIONS

Percutaneous biopsy of renal masses appears to be safe and it carries minimal risk of tumor spread. Urologists should consider increasing the indications for renal biopsy of small renal masses that appear to be renal cell carcinoma, especially in elderly and unfit patients. With more experience and followup preoperative biopsy has the potential to decrease unnecessary treatment since up to a third of small renal masses are now reported to be benign at surgery. Percutaneous biopsy may also allow a better selection of renal tumors for active surveillance and minimally invasive ablative therapies. Finally, there is potential for stratifying initial therapy for metastatic renal cell carcinoma by histological subtype and in the future molecular characteristics.

Formalin-fixed Blood Clots-Additional Histological Findings on Computed Tomography-guided Fine-Needle Aspiration Biopsies in Comparison with Core Biopsies

OBJECTIVE

We investigated the diagnostic yield of histological examined formalin-fixed blood clots (FFBCs) in comparison with the established procedures of fine-needle aspiration biopsy (FNAB) and core biopsy (CB) obtained by percutaneous puncture under computed tomography (CT) guidance.

METHODS

A total of 76 CT-guided punctures with removal of tissue by means of all 3 different techniques (FFBC, FNAB, and CB) were performed. Specimens were obtained from the lung (n=18), mediastinum (n=10), upper abdominal organs (n=32), pelvis (n=4), retroperitoneum (n=4), bones (n=7), and neck (n=1). All results were correlated with the clinical course of the patients (minimum, 6 months; mean period, 10 months). The results of each technique were compared. Results of a combined use of FFBC and FNAB were analyzed.

RESULTS

The overall sensitivity (regardless of biopsy site) was 79% for FFBC, 83% for FNAB, and 95% for CB. In chest biopsies, FFBC reached a sensitivity of 92%, FNAB of 86%, and CB of 96%. In liver biopsies, the sensitivities were 47%, 70%, and 88% for FFBC, FNAB, and CB and, for the remaining biopsy sites, 90%, 90%, and 100%, respectively. The combination of FFBC and FNAB showed higher sensitivities than FFBC and FNAB alone. Overall sensitivity for the combination was 88%, with 92%, 72%, and 100% for thorax, liver, and other locations. A definitive diagnosis was made by FFBC in 87% of cases, by FNAB in 74%, and by CB in 88%. The combination of FFBC and FNAB showed a definite diagnosis in 90% of the cases. A tentative diagnosis has been established in 12%, 7%, 5%, and 4%, respectively. In 4 cases (5%), all 3 techniques failed to yield reliable diagnoses.

CONCLUSIONS

The examination of FFBCs is a useful supplement to the established technique of CT biopsy. In combination with FNAB, FFBC has a comparable sensitivity as CB in chest punctures and other extrahepatic lesions.