Imaging guided biopsies of renal masses

[Biopsies of kidney lesions: when and how?]

The demand for image-guided renal biopsy has increased due to the better detection of renal lesions; however, despite modern imaging techniques many small renal tumors cannot be classified as benign because they cannot be differentiated from renal cell carcinoma. Ultrasound and computed tomography (CT)-guided kidney biopsy is a safe and accurate method in the diagnostics of renal lesions and can be helpful in the selection of new ablative and pharmaceutical forms of treatment and avoid unnecessary operations. This article describes the clinical indications for an image-guided biopsy and discusses factors which should be considered when performing a biopsy.

Renal Tumor Biopsy Technique

Objective:

To review hot issues and future direction of renal tumor biopsy (RTB) technique.

Data Sources:

The literature concerning or including RTB technique in English was collected from PubMed published from 1990 to 2015.

Study Selection:

We included all the relevant articles on RTB technique in English, with no limitation of study design.

Results:

Computed tomography and ultrasound were usually used for guiding RTB with respective advantages. Core biopsy is more preferred over fine needle aspiration because of superior accuracy. A minimum of two good-quality cores for a single renal tumor is generally accepted. The use of coaxial guide is recommended. For biopsy location, sampling different regions including central and peripheral biopsies are recommended.

Conclusion:

In spite of some limitations, RTB technique is relatively mature to help optimize the treatment of renal tumors.

Percutaneous renal tumour biopsy

The use of percutaneous renal tumour biopsy (RTB) as a diagnostic tool for the histological characterization of renal masses has increased dramatically within the last 30 years. This increased utilization has paralleled advances in imaging techniques and an evolving knowledge of the clinical value of nephron sparing surgery. Improved biopsy techniques using image guidance, coupled with the use of smaller gauge needles has led to a decrease in complication rates. Reports from series containing a large number of cases have shown the non-diagnostic rate of RTB to range from 4% to 21%. Re-biopsy has been shown to reduce this rate, while the use of molecular markers further improves diagnostic sensitivity. In parallel with refinements of the biopsy procedure, there has been a rapid expansion in our understanding of the complexity of renal cell neoplasia. The 2013 Vancouver Classification is the current classification for renal tumours, and contains five additional entities recognized as novel forms of renal malignancy. The diagnosis of tumour morphotype on RTB is usually achievable on routine histology; however, immunohistochemical studies may be of assistance in difficult cases. The morphology of the main tumour subtypes, based upon the Vancouver Classification, is described and differentiating features are discussed.

Renal biopsy with 16G needle: a safety study

INTRODUCTION AND OBJECTIVE

The development of percutaneous renal biopsy as a routinary diagnostic procedure for renal masses is topic of discussion for the last few years. However, this technique has been associated with some complications, although infrequent, and morbidity. Our objective is to carry out a descriptive study about complications and outcomes of orthotopic kidney biopsies with 16 G needle.

MATERIAL AND METHODS

A retrospective review of 180 orthotopic ultrasound-guided renal biopsies performed in our service among January 2008 to May 2010 was carried out. The procedure was developed using an automated biopsy gun (16G needle). Multiple clinical variables, early post-procedure complications and its management were collected. Complication rates as well as the relationship between risk factors and occurrence of complications were studied.

RESULTS

Mean age was 55.8 years. The average number of biopsy cylinders per intervention was 2.49. The overall complication rate was 5.6%. An interventionist attitude derived from complication of the procedure was necessary in only 3 patients (1.67%). No surgical interventions were required and no death as consequence of procedure was registered. No relationship between hypertension (P=.09) previous anticoagulation (P=.099) or previous antiaggregation (P=.603) and complications were demonstrated. In 2.8% of biopsies the material obtained was insufficient for diagnosing.

CONCLUSIONS

Percutaneous ultrasound-guided renal biopsy with 16G needle is a safe technique with high diagnostic performance.

Mucosa-associated lymphoid tissue lymphoma arising from the kidney

Primary renal lymphoma is rare, and most are intermediate- and high-grade lymphomas of B-cell lineage, such as diffuse large B-cell or Burkitt lymphoma. We report a case of low-grade B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) arising from the kidney. Only a few cases of primary renal MALT lymphoma have been published.

In vitro comparison of a novel facilitated ultrasound targeting technology vs standard technique for percutaneous renal biopsy

OBJECTIVE

To improve the understanding of the epidemiology of renal cortical neoplasms through pretreatment biopsy, we evaluated a facilitated ultrasound targeting (FUT) technology. The technology allows a needle to be passed through the transducer probe and guided along a virtual dotted line on the monitor. We compared the FUT with standard percutaneous biopsy (PB) technique.

MATERIALS AND METHODS

Forty-eight participants with various levels of training were recruited. Participants performed ultrasound-guided biopsies on phantom models using FUT and the standard biopsy technique in a randomized sequence. The phantom models consisted of pimento olives embedded in an opaque mold of Metamucil and Knox gelatin. Patients were given up to 10 attempts to achieve 3 complete specimens from the olives. Patients rated each biopsy technique. Results were stratified by level of experience.

RESULTS

The mean time to obtain 3 complete biopsy specimens was significantly faster for FUT compared with the standard technique (140 seconds vs 246 seconds, P = .0001). The mean number of attempts needed to obtain 3 specimens was significantly less with FUT compared with the standard technique (4.3 vs 5.6 attempts, P = .0007). Patients reported that FUT was significantly easier to use compared with the standard technique (P = .0005). No significant order effect was observed.

CONCLUSION

In this in vitro comparison, FUT increased the efficiency and efficacy of PB for users of all experience levels. FUT may allow urologists with limited PB experience to perform the procedure reliably and easily. Clinical evaluation of this technology is actively in progress.

Indications for renal fine needle aspiration biopsy in the era of modern imaging modalities

Background:

Renal fine needle aspiration biopsy (FNAB) has become an uncommon procedure in the era of renal helical computed tomography (CT), which has high diagnostic accuracy in the characterization of renal cortical lesions. This study investigates the current indications for renal FNAB. Having knowledge of the specific clinico-radiologic scenario that led to the FNAB, cytopathologists are better equipped to expand or narrow down their differential diagnosis.

Materials and Methods:

All renal FNABs performed during a 6 year interval were retrieved. Indication for the procedure was determined from the clinical notes and radiology reports.

Results:

Forty six renal FNABs were retrieved from 43 patients (14 females and 29 males with a mean age of 52 years [range, 4-81 years]). Twenty one cases (45.6%) were performed under CT-guidance and 25 cases (54.4%) under US-guidance. There were four distinct indications for renal FNAB: (1) solid renal masses with atypical radiological features or poorly characterized on imaging studies due to lack of intravenous contrast or body habitus (30.2%); (2) confirmation of radiologically suspected renal cell carcinoma in inoperable patients (advanced stage disease or poor surgical candidate status) (27.9%); (3) kidney mass in a patient with a prior history of other malignancy (27.9%); and (4) miscellaneous (drainage of abscess, indeterminate cystic lesion, urothelial carcinoma) (14.0%). 36 patients (83.7%) received a specific diagnosis based on renal FNAB cytology.

Conclusions:

Currently, renal fine needle aspiration remains a useful diagnostic tool in selected clinico-radiologic scenarios.

The contemporary role of renal mass biopsy in the management of small renal tumors

The selective use of percutaneous biopsy for diagnosis in renal masses is a relatively uncommon approach when compared to the management of other solid neoplasms. With recent advancements in imaging techniques and their widespread use, the incidental discovery of asymptomatic, small renal masses (SRM) is on the rise and a substantial percentage of these SRM are benign. Recent advances in diagnostics have significantly improved accuracy rates of renal mass biopsy (RMB), making it a potentially powerful tool in the management of SRM. In this review, we will discuss the current management of SRM, problems with the traditional view of RMB, improvements in the diagnostic power of RMB, cost-effectiveness of RMB, and risks associated with RMB. RMB may offer important information enabling treating clinicians to better risk-stratify patients and ultimately provide a more personalized treatment approach for SRM.

Tumour seeding following percutaneous needle biopsy: the real story!

The demand for percutaneous needle biopsy is greater than ever before and with the majority of procedures requiring imaging guidance, radiologists have an increasingly important role in the diagnostic work-up of patients with suspected malignancy. All invasive procedures incur potential risks; therefore, clinicians should be aware of the most frequently encountered complications and have a realistic idea of their likelihood. Tumour seeding, whereby malignant cells are deposited along the tract of a biopsy needle, can have disastrous consequences particularly in patients who are organ transplant candidates or in those who would otherwise expect good long-term survival. Fortunately, tumour seeding is a rare occurrence, yet the issue invariably receives a high profile and is often regarded as a major contraindication to certain biopsy procedures. Although its existence is in no doubt, realistic insight into its likelihood across the spectrum of biopsy procedures and multiple anatomical sites is required to permit accurate patient counselling and risk stratification. This review provides a comprehensive overview of tumour seeding and examines the likelihood of this much feared complication across the range of commonly performed diagnostic biopsy procedures. Conclusions have been derived from an extensive analysis of the published literature, and a number of key recommendations should assist practitioners in their everyday practice.

Border line cases and diagnostic doubts in definition kidney parenchymal and collecting tract neoplasia

Aim of this work is to present cases of renal neoplasms where all available diagnostic modalities and control exams were applied, still explorative surgery was needed. Asymptomatic tissue mass with diagnostic findings of hypovascular renal cell carcinoma and renal pelvic carcinoma were inconclusive. While percutaneous CT guided biopsy is advisable in such cases, it was not performed due to central, hilar localization of the lesions and its small dimensions. In rare cases, such ours are diagnosis is achieved by surgery-histology examination.

[Differential diagnosis of changes in kidney tumors of a small size]

The paper is aimed at presenting several patients treated at the CCS Institute of Urology and Nephrology using the retrospective analysis, in whom differentiation of the kidney tumor change nature and size smaller than 3 cm were decisive for further treatment. Similar cases were not reported or were reported exceptionally rarely in the literature. The diagnosis was established based on ultrasound examination, intravenous urography, computed tomography, magnetic resonance imaging as well as angiography, percutaneous biopsy and pathohistological analysis of the surgical preparation.

Ultrasound-guided biopsy of homogenous solid renal masses

OBJECTIVES

We evaluated the reliability of sonographic criteria in selecting solid renal masses for percutaneous fine-needle biopsy.

METHODS

In study 1 (intraoperative ultrasound study), we prospectively examined 100 consecutive patients scheduled for partial/radical nephrectomy by using two different high-resolution probes (Philips HDI 5000, CT8-4, L12-5; 4-12MHz). The main tumor was intraoperatively evaluated by B-mode and power Doppler sonography. Morphologic characteristics seen on ultrasound were categorized in (non-)homogenous and (non-)cystic renal masses and were related to findings of pathological examination. Study 1 provided the selection criteria for study 2. In study 2 (percutaneous biopsy study), under local anesthesia and with the use of an 18-G needle, we prospectively performed two to three sonographically guided percutaneous biopsies in 30 consecutive patients whose tumors appeared to be homogenous and noncystic according to the sonograph (convex array 3.5MHz, HDI 5000, C5-2 and Falcon 2101 EXL, B+K Medical).

RESULTS

In the ultrasound study, only 16 (22.9%) of the 76 clear-cell carcinomas but all 9 (100%) oncocytoma appeared homogenous and noncystic on high-resolution intraoperative ultrasound. By applying these results to 30 patients of study 2 (18 men, 12 women; aged 63+/-7.7 yr, tumor size 29+/-11.3mm) who met these sonographic criteria on preoperative transabdominal ultrasound, we bioptically diagnosed 8 (26.7%) benign tumors; 25 of 30 (83.3%) patients were accurately diagnosed. Small tumors (<3cm), decreased breathing compliance, and medially located renal lesions seem to negatively influence biopsy results.

CONCLUSIONS

Kidney tumors that appear noncystic and homogenous on preoperative ultrasound are more likely to be of benign origin. Ultrasound-guided percutaneous biopsy of these solid renal masses could determine renal tumor patients for whom surveillance might be an option. However, experienced and dedicated histopathologic evaluation remains crucial to observe patients with clearly benign biopsy results. All even slightly questionable biopsy findings require surgical exploration.

Renal Masses in the Adult Patient: The Role of Percutaneous Biopsy

Although percutaneous renal mass biopsy with cross-sectional imaging guidance has long been considered to be safe and accurate, there have been recent advances in imaging, interventional, and cytologic techniques that have increased the role of percutaneous biopsy in the diagnosis of renal masses. Today, biopsy plays a fundamental role in the care of patients with a renal mass. Biopsy results are used to confirm the diagnosis of renal cancers, metastases, and infections, and there is increasing evidence to suggest that biopsy can help subtype and grade many primary renal cancers. Because a considerable fraction of small solid renal masses are benign and do not need treatment, there is an increasing need to diagnose them. Biopsy after a full imaging work-up can help prevent unnecessary and potentially morbid surgical and ablation procedures in a substantial number of patients. Although more data are needed to understand the overall accuracy of biopsy for the diagnosis of benign lesions, many can be diagnosed with the aid of biopsy findings. This article reviews reported experience with percutaneous renal mass biopsy, discusses the technical factors that contribute to results, and details seven specific clinical settings that should prompt the clinician to consider percutaneous biopsy when encountering a renal mass.

The role of ultrasound in renal insufficiency: the essentials

Sonography is the best screening modality to evaluate patients presenting with renal insufficiency. Ultrasound findings can be normal in patients with renal disease, especially in prerenal azotemia and acute parenchymal renal disease. Echogenic kidneys indicate the presence of parenchymal renal disease; the kidneys may be of a normal size or enlarged. Small kidneys suggest advanced stage chronic kidney disease. Uncommonly, cystic disease of the kidney, especially adult type polycystic kidney disease may be the cause of the patient's renal insufficiency with bilaterally enlarged kidneys containing multiple cysts of various sizes. If hydronephrosis is present, the level and cause of the obstruction should be sought. When ultrasound cannot diagnose the level and cause of obstruction, other imaging modalities, including CT and MRI may be useful. When renovascular disease (arterial stenosis or venous thrombosis) is suspected, spectral and color Doppler can be useful in detecting abnormalities.

Ultrasound-Guided Biopsies: Tricks, Needle Tips, and Other Fine Points

Ultrasound (US)-guided biopsy of thyroid nodules, abdominal masses, liver masses, random core liver biopsies, as well as aspiration of abdominal or pleural fluid is now routine practice. The ability of US to guide biopsy of abnormalities seen on cross-sectional imaging studies is well recognized as an efficient and effective means of achieving a tissue diagnosis. Its use requires basic knowledge of US image analysis, but clinically useful intuitive and nonintuitive methods can enhance its strengths. The purpose of this review is to provide a practical guide to some of these tricks that may be useful in everyday clinical practice.

Percutaneous biopsy of renal masses: sensitivity and negative predictive value stratified by clinical setting and size of masses

OBJECTIVE

The purpose of our retrospective study was to evaluate the sensitivity and negative predictive value of percutaneous biopsy of renal masses stratified by clinical setting and the size of the mass.

MATERIALS AND METHODS

We categorized 115 consecutive percutaneous biopsies of renal masses in 113 patients into four clinical settings and three groups of mass sizes. The sensitivity and negative predictive value were computed (with 95% confidence intervals [CI]) for each clinical setting and for each size group.

RESULTS

For all procedures (n = 115), the sensitivity and negative predictive value were 90% (95% CI, 81-95%) and 64% (95% CI, 44-81%), respectively. For patients with a known malignancy who presented with a renal mass (n = 55), the sensitivity and negative predictive value were 90% (95% CI, 78-96%) and 38% (95% CI, 10-74%), respectively. For patients with no known malignancy and suspected unresectable tumor (n = 36), the sensitivity and negative predictive value were 92% (95% CI, 76-98%) and 0%, respectively. For patients with no known malignancy who presented with a cystic mass (n = 16), the sensitivity and negative predictive value were 33% (95% CI, 2-87%) and 87% (95% CI, 58-98%), respectively. For patients who were not surgical candidates with a renal cell carcinoma (n = 8) that was thought to be resectable, both the sensitivity and negative predictive value were 100%. For masses 3 cm and less (n = 31), the sensitivity and negative predictive value were 84% (95% CI, 63-95%) and 60% (95% CI, 27-86%), respectively. For masses between 4 and 6 cm (n = 42), the sensitivity and negative predictive value were 97% (95% CI, 83-100%) and 89% (95% CI, 51-99%), respectively. For masses greater than 6 cm (n = 42), the sensitivity and negative predictive value were 87% (95% CI, 71-95%) and 44% (95% CI, 15-77%), respectively.

CONCLUSION

Percutaneous renal mass biopsy has a high sensitivity in three clinical settings: patients with a known malignancy, patients with no known malignancy and suspected unresectable tumor, and nonsurgical patients with a mass suspected to be a resectable renal cell carcinoma. Negative results in small (< or = 3 cm) and large (> 6 cm) masses should be viewed with caution.

Evaluation of sonographically guided percutaneous core biopsy of renal masses

OBJECTIVE

Our objective was to determine the utility of sonographically guided percutaneous core biopsy to evaluate renal masses.

MATERIALS AND METHODS

We conducted a retrospective analysis of our imaging-guided procedures from January 1999 to June 2001. We performed 26 sonographically guided percutaneous core biopsies of renal masses in 26 patients. From two to five specimens were obtained from a single mass in each patient using an 18-gauge automated biopsy system. We examined the patients' medical records, pathology results, and imaging studies. Core biopsy results were compared with surgical pathology (n = 6) or clinical follow-up (n = 20).

RESULTS

All biopsies provided sufficient material for analysis. Biopsy findings were positive for malignancy in 19 (73%) of 26 masses. Histologic diagnoses included renal cell carcinoma were (n = 11), metastasis (n = 3), lymphoma (n = 2), and transitional cell carcinoma (n = 2). Specific cell type characterization could not be made on one biopsy, but the specimens were highly suspicious for malignancy. Biopsy revealed seven (27%) of 26 benign diagnoses: oncocytoma (n = 3), angiomyolipoma (n = 2), and fibrosis (n = 2). The average follow-up period for patients with benign diagnoses was 10 months. One case of surgically proven necrotic pyelonephritis was mischaracterized as fibrosis at core biopsy. Sonographically guided percutaneous core biopsy of renal masses showed a sensitivity of 100% and a specificity of 100% for the diagnosis of malignancy. The core specimens yielded a specific diagnosis in 92% (24/26) of masses. No immediate complications occurred after the procedure. One patient developed a pseudoaneurysm that presented 3 months after the biopsy. CONCLUSION. Sonographically guided percutaneous core biopsy is a reliable and accurate method for evaluating renal masses.