Fine Needle Aspiration Using Improved Agar Microbiopsy is Highly Concordant With Renal Mass Final Diagnosis and Subclassification

A systematic review on performance characteristics of FNA of renal lesions: It is time for a standardized classification system

BACKGROUND

The incidence of renal tumors has steadily increased over the past decade. In this study, the authors performed a systematic review and analysis of the literature on renal fine-needle aspiration (FNA) to determine its performance and explore whether a standardized classification system can be used for reporting renal FNA cytology.

METHODS

A systematic search of published articles on renal FNA was conducted. The data on FNA and histologic diagnosis were extracted and categorized, and the risk of malignancy was calculated. Different scenarios were used to estimate FNA performance statistics.

RESULTS

Of the 3766 potentially relevant studies, 23 met the inclusion criteria of the study. The 2231 FNA cases included were re-categorized according to the classification system, rendering 142 (6.36%) nondiagnostic, 270 (12.1%) nonneoplastic, 271 (12.14%) benign neoplasm, 65 (2.91%) renal neoplasm with unknown malignant potential, oncocytic type, 25 (1.12%) atypia of undetermined significance, 60 (2.68%) suspicious for malignancy, and 1398 (62.66%) malignant FNA diagnoses. The risk of malignancy in these cases was 65.4%, 18.1%, 16.6%, 16.9%, 60%, 73.3%, and 96.9%, respectively. According to the classification system, the study indicated that the accuracy of renal FNA was between 91% and 95%, the sensitivity was 90.9%-96.7%, and the specificity was 82%-92% in different scenarios.

CONCLUSIONS

There is a need for a standardized reporting in renal cytology that will improve the sensitivity and accuracy of renal cytology, reduce the rate of indeterminate diagnoses, and alter the management strategies of renal lesions. Based on the available literature, a new reporting system is proposed, including categories with an associated risk of malignancy.

Preparation of compact agarose cell blocks from the residues of liquid-based cytology samples

Background

Inevitable loss of diagnostic material should be minimized during cell block preparation. We introduce a modified agarose cell block technique that enables the synthesis of compact cell blocks by using the entirety of a cell pellet without the loss of diagnostic material during cell block preparations. The feasibility of this technique is illustrated by high-throughput immunocytochemistry using high-density cell block microarray (CMA).

Methods

The cell pellets of Sure- Path residues were pre-embedded in ultra-low gelling temperature agarose gel and re-embedded in standard agarose gel. They were fixed, processed, and embedded in paraffin using the same method as tissue sample processing. The resulting agarose cell blocks were trimmed and represented on a CMA for high-throughput analysis using immunocytochemical staining.

Results

The SurePath residues were effectively and entirely incorporated into compact agarose cell buttons and embedded in paraffin. Sections of the agarose cell blocks revealed cellularities that correlated well with corresponding SurePath smears and had immunocytochemical features that were sufficient for diagnosis of difficult cases.

Conclusions

This agarose-based compact cell block technique enables preparation of high-quality cell blocks by using up the residual SurePath samples without loss of diagnostic material during cell block preparation.

Current status of renal biopsy for small renal masses

Small renal masses (SRMs) are defined as radiologically enhancing renal masses of less than 4 cm in maximal diameter. The incidence of renal cell carcinoma (RCC) has increased in recent years, which is mainly due to the rise in incidental detection of localized SRMs. However, the cancer-specific mortality rate is not increasing. This discrepancy may be dependent on the indolent nature of SRMs. About 20% of SRMs are benign, and smaller masses are likely to have pathologic characteristics of low Fuhrman grade and clear cell type. In addition, SRMs are increasingly detected in elderly patients who are likely to have comorbidities and are a high-risk group for active treatment like surgery. As the information about the nature of SRMs is improved and management options for SRMs are expanded, the current role of renal mass biopsy for SRMs is also expanding. Traditionally, renal mass biopsy has not been accepted as a standard diagnostic tool in the clinical scenario because of several issues about safety and accuracy. However, current series on SRM biopsy have reported high diagnostic accuracy with rare complications. Studies of modern SRM biopsy have reported diagnostic accuracy greater than 90% with very high specificity. Also, current series have shown very rare morbid cases caused by renal mass biopsy. Currently, renal biopsy of SRMs can be recommended in most cases except when patients have imaging or clinical characteristics indicative of pathology and in cases in which conservative management is not considered.

Morphologic and immunocytochemical performances of effusion cell blocks prepared using 3 different methods

With increased use of the ThinPrep method for nongynecologic specimens, cell blocks are more commonly prepared by harvesting cells that are fixed in CytoLyt solution. The current study compared morphologic and immunocytochemical performance of effusion cell blocks prepared using CytoLyt-prefixed thrombin clot (CTC) with plasma thrombin clot (PT) and HistoGel (HG) preparation. The study included a total of 25 malignant or benign serous fluids. Three individual cell block materials were simultaneously prepared from each of the 25 effusion specimens using the CTC, PT, or HG method. H&E staining and immunostaining for pancytokeratin (pan-CK), carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA), B72.3, HBME-1, estrogen receptor (ER), progesterone receptor (PR), CD45, CD20, and CD3 were then performed. The CTC preparation revealed compatible cellularity and good cellular details. In addition, CTC cell blocks revealed a similar percentage of cells with positive immunostaining along with the strongest intensity and the least background staining. The CTC method can be used reliably as an adjunct to other preparation techniques.

Massive retroperitoneal hemorrhage from a giant renal angiomyolipoma treated by selective arterial embolization with an Amplatzer Vascular Plug II

We report on a 36-year-old Caucasian woman who presented to the emergency department with post-traumatic retroperitoneal bleeding diagnosed by computed tomography. After clinical stabilization of the patient, selective arterial embolization was performed. The angiomyolipoma's feeding artery was successfully treated with an 8-mm Amplatzer Vascular Plug Type II. The upper pole of the left kidney, which was supplied by a separate upper renal artery, was conserved. Consequently, the renal angiomyolipoma became necrotic and surgical resection of the entire renal angiomyolipoma was performed. This case illustrates a simple and effective application of an Amplatzer Vascular Plug occluder for vessel embolization, without additional coiling.

The penetration of renal mass biopsy in daily practice: a survey among urologists

BACKGROUND AND PURPOSE

The vast increase in recent publications on renal mass biopsy (RMB) suggests an increased interest in the subject. The objective of the survey was to assess the use of RMB in current urologic practice, including related factors such as indications and patterns in practice.

METHODS

The link to a web-based questionnaire ( www.surveymonkey.com ) was sent to all registered e-mail addresses (1854) of members of the Endourological Society in December 2010. The questionnaire contained six epidemiologic questions, 10 regarding patterns of practice, one regarding the influence of the literature, and one on future techniques. Chi-square test (for trends) was used to assess statistical significant differences among categorical answers.

RESULTS

In total, 190 responders completed the survey of whom 73% indicated performing RMB "never" or "rarely" compared with 9% performing RMB in 25% to 100% of cases. Thirteen percent of responders reported never to take a RMB. Of the latter, significantly fewer practice in university hospitals (6% vs 20%-30%, P=0.003). Main indications to perform RMB are still tumors in solitary/transplant kidneys and in metastatic disease. Lack of influence on clinical management and risk of false negatives were the main reasons not to perform biopsies. Sixty-one percent prefer histological biopsies compared with 8% who prefer cytological aspiration; 31% indicated that they combine both techniques. Other tissue differentiation techniques (Optical Coherence Tomography, Raman-spectroscopy) are unknown to 65% of urologists.

CONCLUSION

RMB is not yet applied widely in urologic practice, with academic urologists performing RMB less infrequently. Core biopsies are still preferred, although combined with cytologic punctures by a considerable number of responders.

Renal mass sampling: an enlightened perspective

Renal mass sampling (RMS) can be carried out by core biopsy or fine needle aspiration with each presenting potential advantages and limitations. The literature about RMS is confounded by a lack of standardized techniques, ambiguous terminology, imprecise definitions of accuracy, substantial rates of non-informative biopsies, and recurrent diagnostic challenges with respect to eosinophilic neoplasms. Despite these concerns, RMS has an expanding role in the evaluation and treatment of renal masses, in order to stratify biological aggressiveness and guide management that can range from surgery to active surveillance. Non-informative biopsies can be managed with surgical excision or repeat biopsy, with the latter showing encouraging results in recent studies. We propose a new classification in which all biopsies are categorized as non-informative versus informative, with the latter being subclassified as confirmed accurate, presumed accurate or confirmed inaccurate. This terminology will facilitate the comparison of results from various studies and stimulate progress. Incorporation of novel biomarkers and molecular fingerprinting into RMS protocols will likely allow for more rational management of patients with renal masses in the near future.