Fine-needle aspiration of renal masses in adults: analysis of results and diagnostic problems in 108 cases

Diagnostic renal mass biopsy is associated with individual categories of PADUA and RENAL nephrometry scores: Analysis of diagnostic and concordance rates with surgical resection

BACKGROUND

Renal mass biopsy (RMB) is a safe and accurate method for diagnosis and clinical management of renal masses. However, the non-diagnostic rate is a limiting factor. We tested the hypothesis that imaging characteristics and anatomic complexity of the mass may impact RMB diagnostic outcome using the preoperative aspects and dimensions used for an anatomical (PADUA) classification and radius-exophytic/endophytic-nearness-anterior/posterior-location (RENAL) score.

MATERIAL AND METHODS

Single institution, retrospective study of 490 renal masses from 443 patients collected from 2001 to 2018. Outcome measurements include (1) diagnostic and concordance rates amongst RMB types and RMB with surgical resection specimens; (2) association between diagnostic RMB and anatomical complexity of renal masses. The analysis was conducted in unselected masses and small renal masses (SRMs).

RESULTS

RMB was performed by fine needle aspiration (FNA), core needle biopsy (CNB), or both (FNA+CNB). Non-diagnostic rate was significantly higher for FNA compared to CNB and FNA+CNB in both unselected and SRMs. Subset analysis in the FNA+CNB group showed similar diagnostic rates for FNA and CNB. In unselected masses, specificity for FNA, CNB, and FNA+CNB was 100%. Sensitivity was higher for CNB (90.1%, P = 0.002) and FNA+CNB (96.3%, P = 0.004) compared to FNA (66.7%). For unselected masses, endophytic growth predicted a non-diagnostic CNB. R.E.N.A.L location entirely between the polar lines (central) and entirely above the upper polar line predicted a diagnostic CNB. Sonography-guidance predicted a diagnostic FNA. For SRMs, non-diagnostic CNB was associated with endophytic growth, while diagnostic CNB was associated with renal sinus invasion and operator experience. More cystic masses were sampled by FNA, but diagnostic results were similar for FNA and CNB.

CONCLUSIONS

Endophytic growth consistently predicted a non-diagnostic CNB in unselected and SRMs, whereas sonography-guidance predicted a diagnostic FNA. Cystic masses could be adequately sampled by FNA.

Adult Renal Neoplasms: Cytology, Immunohistochemistry, and Cytogenetic Characteristics

Tissue sampling of renal masses is traditionally performed using percutaneous sonographic or CT guidance core biopsy (CB) with or without touch preparation cytology and/or fine-needle aspiration cytology (FNAC). The combined used of CB and FNAC is expanding in clinical practice, especially in small renal masses and plays a pivotal role in therapeutic decision making. Grouping the renal neoplasms in differential diagnostic groups helps in choosing specific immunohistochemical markers and reaching an accurate diagnosis.

Diagnostic accuracy of image-guided biopsies in small (<4 cm) renal masses with implications for active surveillance: a systematic review of the evidence

OBJECTIVE:

To determine the safety and diagnostic accuracy of renal tumour biopsies in a defined population of small renal masses (SRMs) only <4 cm using 3 × 2 table, intention to diagnose approach. 3 × 2 table approach examines indeterminate results as a separate category rather than pushing these through traditional 2 × 2 table (four-cell matrix) approach.

METHODS:

A highly sensitive search was performed in the Cochrane Library, Database of Abstracts of Reviews of Effects; MEDLINE and MEDLINE in Process, EMBASE and conference proceedings (1966-2016) for the acquisition of data on the diagnostic accuracy and complications of RTB in patients with SRM <4 cm. Methodological quality and risk of bias was assessed using QUADAS-2. Test characteristics were calculated using conventional 2 × 2 contingency table analysis excluding non-diagnostic biopsies, and an intention-to-diagnose approach with a 3 × 2 table for pooled estimates of the sensitivity and specificity.

RESULTS:

A total of 20 studies were included with a total sample size of 974. The pooled estimates for sensitivity and specificity of RTB based upon univariate analysis using 2 × 2 table observed sensitivity 0.952 [confidence interval (CI) 0.908-0.979] and specificity 0.824 (CI 0.566-0.962). Using the 3 × 2 table and intention-to-diagnose principle, sensitivity 0.947 (CI 0.925-0.965) and specificity 0.609 (CI 0.385-0.803) decreased.

CONCLUSION:

RTB in SRMs (<4 cm) is associated with a high diagnostic sensitivity but poor specificity when non-diagnostic results are included by a 3 × 2 table for analysis (intention to diagnose approach). Risk of non-diagnostic results and poor quality of research need addressing through future studies, preferably by a well-designed prospective study appropriately powered for diagnostic accuracy using valid reference standards.

ADVANCES IN KNOWLEDGE:

A comprehensive synthesis of literature on image-guided biopsies in SRMs using a different methodology and study design.

Core Needle Biopsy and Fine Needle Aspiration Alone or in Combination: Diagnostic Accuracy and Impact on Management of Renal Masses

PURPOSE

Fine needle aspiration with and without concurrent core needle biopsy is a minimally invasive method to diagnose and assist in management of renal masses. We assessed the pathological accuracy of fine needle aspiration compared to and associated with core needle biopsy and the impact on management.

MATERIALS AND METHODS

We performed a single institution, retrospective study of 342 cases from 2001 to 2015 with small and large renal masses (4 or less and greater than 4 cm, respectively). Diagnostic and concordance rates, and the impact on management were analyzed.

RESULTS

Adequacy rates for fine needle aspiration only, core needle biopsy only and fine needle aspiration plus core needle biopsy were 21%, 12% and 8% (aspiration vs aspiration plus biopsy p <0.026). In the aspiration plus biopsy group adding aspiration to biopsy and biopsy to aspiration reduced the inadequacy rate from 23% to 8% and from 27% to 8% for a total reduction rate of 15% and 19%, respectively, corresponding to 32 cases (9.3%). Rapid on-site examination contributed to a 22.5% improvement in fine needle aspiration adequacy rates. In this cohort 30% of aspiration only, 5% of biopsy only and 12% of aspiration plus biopsy could not be subtyped (aspiration vs biopsy p <0.0001, aspiration vs aspiration plus biopsy p <0.0127 and biopsy vs aspiration plus biopsy p = 0.06). The diagnostic concordance rate with surgical resection was 99%. Conversion of an inadequate specimen to an adequate one by a concurrent procedure impacted treatment in at least 29 of 32 patients. Limitations include the retrospective design and accuracy measurement based on surgical intervention.

CONCLUSIONS

Fine needle aspiration plus core needle biopsy vs at least fine needle aspiration alone may improve diagnostic yield when sampling renal masses but it has subtyping potential similar to that of core needle biopsy only.

Percutaneous biopsy of the renal mass: FNA or core needle biopsy?

BACKGROUND

In recent years, there have been increasing indications for percutaneous renal biopsy. Fine-needle aspiration (FNA), with or without core needle biopsy (CB), has been used increasingly in the management of renal tumors at the study institution.

METHODS

A computerized search of laboratory records was conducted to retrieve FNA cases of renal masses as well as the correlating CB and/or nephrectomy specimens. The cases spanned a period of 10 years (2006-2015). The diagnoses were classified into 5 categories: malignant, suspicious for malignancy, neoplastic, atypical, and negative/nondiagnostic. Based on the results of the nephrectomy specimens, the diagnostic rate, sensitivity, and diagnostic accuracy were calculated among 3 groups of specimens: FNA only, CB only, and combined FNA and CB.

RESULTS

A total of 247 cases of FNA with 123 correlating CB and 101 follow-up nephrectomy specimens were identified. The diagnostic rate, sensitivity, and diagnostic accuracy were 72%, 78%, and 96%, respectively, for FNA; 87%, 92%, and 94%, respectively, for CB; and 92%, 92%, and 94%, respectively, for the combined FNA and CB group. Renal cell carcinoma and its variants were the most common histologic diagnoses (112 of 174 cases; 64%). Significant diagnostic discrepancy was noted in one case: a malignant melanoma that was misdiagnosed as renal cell carcinoma in both the preoperative FNA specimen and in the CB specimen.

CONCLUSIONS

In the current study, both FNA and CB demonstrated excellent diagnostic accuracy (96% and 94%, respectively). The combination of FNA and CB was found to significantly improve the diagnostic rate when compared with either FNA alone (92% vs 72%; P<.05) or CB alone (92% vs 87%). Cancer Cytopathol 2017;125:407-15. © 2017 American Cancer Society.

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.

Metastases to the kidney: a comprehensive analysis of 151 patients from a tertiary referral centre

OBJECTIVE

To describe the presentation, treatment and outcomes of patients with metastatic tumours to the kidney treated at a tertiary referral centre.

PATIENTS AND METHODS

We retrospectively identified 151 patients diagnosed with a primary non-renal malignancy with renal metastasis. Clinical, radiographic and pathological characteristics were assessed. Overall survival (OS) was calculated using Kaplan-Meier methods.

RESULTS

The median patient age was 56.7 years. The most common presenting symptoms were flank pain (30%), haematuria (16%) and weight loss (12%). Most primary cancers were carcinomas (80.8%). The most common primary tumour sites were lung (43.7%), colorectal (10.6%), head and neck (6%), breast (5.3%), soft tissue (5.3%) and thyroid (5.3%). Renal metastases were typically solitary (77.5%). Concordance between radiologist and clinician imaging assessment was 54.0%. Three ablations and 48 nephrectomies were performed. For non-surgical patients, renal metastasis diagnosis was made with fine-needle aspiration or biopsy. The median OS from primary tumour diagnosis was 3.08 years and the median OS from time of metastatic diagnosis was 1.13 years. For patients treated with surgery, median OS from primary tumour diagnosis was 4.81 years, and OS from metastatic diagnosis was 2.24 years.

CONCLUSIONS

Metastases to the kidney are a rare entity. Survival appears to be longer in patients who are candidates for and are treated with surgery. Surgical intervention in carefully selected patients with oligometastatic disease and good performance status should be considered. A multidisciplinary approach with input from urologists, oncologists, radiologists and pathologists is needed to achieve the optimum outcomes for this specific patient population.

Diagnostic significance of biopsies in renal masses

Introduction

We investigated the reliability and mapping of percutaneous needle core biopsies in the kidney in histopathological diagnosis of renal masses particularly for those with suspicious radiologic appearance in an attempt to prevent unnecessary nephrectomies.

Material and methods

Overall, 96 cases were included in our study that underwent radical nephrectomy or partial nephrectomy due to renal mass between November 2007 – March 2010. Ex–vivo biopsies 1 cm apart were obtained from the peripheral region of the mass. Additionally, half of these peripheral biopsies were obtained from the central region of the mass. Diagnostic yield of the biopsy cores were correlated. Sensitivity and specificity of peripheral and central biopsies in differentiating benign and malignant tissues were calculated.

Results

Sensitivity and specificity in differentiating malignant lesions were 93% and 87%, and 90% and 93% for peripheral and central biopsies, respectively. Positive and negative predictive values were 97% and 68%, and 98% and 64% for peripheral biopsies and central biopsies, respectively. Hazard ratio for cigarette smoking and presence of necrosis on CT scans were 4.76 (CI 1, 6–14.3; p = 0.04) and 3.32 (CI 1,2–9.2; p = 0.017) and 3.71 (CI 1.3–10.7; p = 0.013) and 3,51 (CI 1.3–9.6; p = 0.012) for peripheral and central biopsies, respectively.

Conclusions

Kidney biopsies can be performed in suspicious renal masses of central and peripheral biopsies with similar efficacy.

Diagnosis of Metastatic Renal Cell Carcinoma on Fine-Needle Aspiration Cytology

Fine-needle aspiration has assumed an increasingly important role in the diagnosis and management of patients with advanced stage cancer. Given its predilection for metastases to distant sites and organs at the time of presentation, metastatic renal cell carcinoma (RCC) is not infrequently encountered in the setting of fine-needle aspiration for initial diagnosis. In some instances, fine-needle aspiration may be the only opportunity to obtain diagnostic tissue to diagnose and subclassify RCC. Therefore, cytopathologists and cytotechnologists should be familiar with and recognize the cytomorphology of RCC and the ancillary studies that can be used to confirm and subclassify RCC. Herein, we describe a case of metastatic RCC initially diagnosed on fine-needle aspiration, discuss the cytomorphologic features of RCC subtypes, and review pertinent ancillary immunohistochemical and cytogenetic adjuncts.

Role of percutaneous needle biopsy for renal masses

The role of percutaneous renal mass biopsy has expanded considerably in the past 10 years. The incidence of incidentally detected small (< 4 cm) solid renal masses is on the rise, and despite a commensurate increase in nephron-sparing treatment, the mortality rate from renal cell carcinoma remains the same. Earlier detection and treatment have not had dramatic effects on population outcome, implying that not all small renal masses will grow to be life-limiting. Indeed, many small solid renal masses are benign, and among those that are malignant, not all share the same malignant behavior. Percutaneous biopsy provides a minimally invasive method for discriminating benign from malignant renal masses, and portends the potential for stratifying malignant risk. With recent improvements in image-guided equipment and technique, percutaneous renal mass biopsy can be performed safely and effectively, with a low complication rate (< 5%) and a high diagnostic yield (> 90%).

Genitourinary cytopathology (kidney and urinary tract)

FNA of kidney masses have been performed for the diagnosis of mass lesions,confirmation of advanced neoplasia and metastases, and staging of tumors. In the past, the decision of whether to perform a nephrectomy used to be based on radiographic features and size, precluding the use of FNA. Today, where treatment is not limited to surgery alone, the indications for renal FNA have expanded. Most small renal masses are asymptomatic and are detected incidentally due to improved imaging techniques. Although most urologists agree that the standard of care for renal masses is surgery, if the patient is an elderly individual, or has comorbidities a preoperative FNA could be useful in guiding the management.When we look at data from large referral institutions such as Mayo Clinic, Johns Hopkins Medical Institutions, and the Cleveland Clinic approximately 30 %of the renal masses are benign [86---88]. Therefore, as astutely pointed out by Volpe et al.[3], there is a role for precise pretreatment characterization of the renal masses by FNA, which would decrease the unnecessary treatment for benign diseases and reduce the treatment-related mortality and morbidity in addition to reducing patient care costs.To date, urine cytology remains the gold standard for bladder cancer screening.It has been, and still is, the test against which all new tests are compared when evaluating potential bladder tumor markers. The answer to whether urine cytology possesses the optimal combination of sensitivity and specificity to retain consideration as the best screening device depends on the goals of the practice. Urine cytology has excellent specificity with only few false-positive cases. Its overall sensitivity (including both high grade and low grade lesions) is poor, but this is explained by poor criteria for identifying well-differentiated, low-grade urothelial carcinoma in cytology. The natural history of low grade lesions is that of multiple superficial recurrences in 70 - 80 % of patients, with only a minority ( 10-15 %)progressing to muscle invasive or metastatic disease [89]. Patients with low-grade urothelial carcinoma are at low risk for progression, they are monitored primarily for the development of a subsequent high grade tumor [90]. Therefore, as suggested by Koss, detection of new low-grade lesions may be clinically irrelevant as compared to early detection of disease progression [39]. Contrary to the low grade lesions, however, urine cytology often results in the identification of high-grade malignant cells even before a cystoscopically distinguishable gross lesion is present. In the last 20 years, a number of noninvasive test have been developed to detect urothelial carcinoma. Although some have been able to show a better sensitivity compared to cytology, only a few have been close to reaching the sensitivity seen in cytology. Most of these tests have not added much to the diagnostic evaluation. Combining some of the new markers with each other and/or cytologic evaluation may optimize their performance status.

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 role of biopsy in incidental renal tumours

PURPOSE

Historically, the biopsy of renal masses was not advocated, and to date there remains some controversy on the role of biopsy for renal masses in making treatment decisions. With the widespread use of imaging methods, the incidental diagnosis of renal masses has increased, necessitating renal biopsies to better plan the management of these tumours. Here I review previous reports to define the role of biopsy in incidental renal tumours.

METHODS

Data were obtained from English-language studies listed in PubMed on the use of renal biopsy for evaluating incidental solid small renal tumours.

RESULTS

The biopsy of small renal tumours is increasingly accepted due to: the increase in the incidence of small renal tumours; the finding that a significant number of these tumours are benign; the availability of new management options, such as ablative therapy and surveillance strategies; that imaging alone is unable to predict the biological behaviour of these tumours; and advances in the pathological evaluation of the biopsies. The biopsy procedure has an acceptable complication rate but is not free of limitations. The current recommendations for the use of renal biopsy in small renal tumours are: to help in differentiating benign from malignant renal tumours; before or during ablative therapies and during the follow-up after ablative therapies, for defining treatment success or failure; and to exclude nonrenal cell primary tumours (metastasis and lymphoma) or benign conditions (abscess), which may not require surgery.

CONCLUSIONS

The biopsy of small renal tumours is a safe and accurate procedure, and can help in the planning of definitive patient management.

Utility of PAX8 and PAX2 immunohistochemistry in the identification of renal cell carcinoma in diagnostic cytology

The diagnosis of metastatic renal cell carcinoma (RCC) in cytology specimens may be difficult to confirm on the basis of cytomorphology alone. Often, immunohistochemistry serves as an important adjunct in confirming this diagnosis. Recently, PAX2 was shown to be useful in this regard. In this study, we sought to compare the utility of PAX8 to that of PAX2 immunohistochemistry in the diagnosis of RCC in cytology specimens. First, we verified the performance of PAX8 immunohistochemistry on a tissue microarray (TMA) composed of 54 cases of RCC; PAX8 immunoreactivity was seen in at least 10% of the tumor cells in all cases. Next, we applied PAX8 immunohistochemistry to cell block sections prepared from 24 cases of RCC, obtained from fine-needle aspirates and effusion specimens. PAX2 immunohistochemistry was performed for comparison. Immunopositivity was defined as the presence of nuclear staining in at least 10% of tumor cell nuclei. Immunoreactivity for PAX8 and PAX2 was seen in 21 (88%) and 20 (83%) of the 24 cases, respectively. The presence of either PAX8 or PAX2 immunostaining was present in 22 of 24 cases, thus showing a total sensitivity of 92%. Overall, the results indicate that PAX8 and PAX2 are diagnostically useful adjuncts in confirming the diagnosis of RCC in cytology specimens.

Feasibility of differential diagnosis of kidney tumors by comparative genomic hybridization of fine needle aspiration biopsies

The association of a genetic analysis that could improve the diagnostic accuracy of renal cell tumors in biopsy samples would allow better-informed therapeutic decisions. We performed comparative genomic hybridization (CGH) on an ex vivo fine-needle aspiration (FNA) biopsy and a tumor fragment obtained from 75 patients consecutively diagnosed with renal tumors and subjected to radical nephrectomy. The pattern of genomic changes by CGH was used blindly to classify the renal tumors and the genetic findings were subsequently compared with the histopathologic diagnosis. In particular cases, including in two carcinomas with morphologically distinct tumor areas, we performed FISH with several locus-specific probes, and looked for VHL point mutations, exonic rearrangements, or promoter methylation. CGH was successful in 82.7% FNA biopsies and in 96% tumor fragments, with the former allowing genetic diagnosis in 75% of renal cell tumors. The genetic and the initial histological classification differed in two renal neoplasias, but the genetic diagnosis was confirmed after review. The genetic pattern correctly diagnosed 93.5% of clear cell renal cell carcinomas (RCC), 61.5% of chromophobe RCC, 100% of papillary RCC, and 14.3% of oncocytomas, with the negative predictive value being 93.9, 90.7, 100, and 90.2%, respectively. The positive predictive value and specificity of copy number profiles was 100%. We demonstrate that genetic diagnosis by CGH on FNA biopsies can improve differential diagnosis in patients with kidney tumors.

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.

Percutaneous biopsy of primary tumor in metastatic renal cell carcinoma to predict high risk pathological features: comparison with nephrectomy assessment

PURPOSE

As treatment options evolve for metastatic renal cell carcinoma, there is a need for predictive information to help guide therapy. We assessed the accuracy of percutaneous primary tumor biopsy for metastatic renal cell carcinoma by comparing biopsy findings to final nephrectomy pathology in patients undergoing cytoreductive nephrectomy.

MATERIALS AND METHODS

Using an institutional database we reviewed the records of patients who underwent percutaneous primary tumor biopsy before cytoreductive nephrectomy. In patients who underwent biopsy elsewhere pathology findings were re-reviewed at our institution. Differences in accuracy based on biopsy technique, imaging modality and biopsy period were determined by chi-square analysis.

RESULTS

We identified 166 patients who underwent percutaneous biopsy of the primary tumor before cytoreductive nephrectomy between 1991 and 2007, and had data available for review. Median pathological tumor size was 9.1 cm (range 3 to 32). Median time from biopsy to surgery was 46 days (range 6 to 717). Of 104 patients in whom biopsy was assigned a Fuhrman nuclear grade 33 (31.7%) had the same grade in the nephrectomy specimen, including 74 of 109 (67.9%) when considering only high or low grade. Grade change by more than 2 points was seen in 18 of 104 patients (17.3%). Sarcomatoid features were present in 34 of 166 nephrectomy specimens (20.5%) but only 4 (11.8%) were identified preoperatively.

CONCLUSIONS

In patients with metastatic renal cell carcinoma percutaneous renal biopsy has poor accuracy to assess Fuhrman nuclear grade or sarcomatoid features. Physicians should use caution when using biopsy data to guide therapy.

Diagnostic difficulties and pitfalls in rapid on-site evaluation of endobronchial ultrasound guided fine needle aspiration

BACKGROUND

One of the novel techniques utilizing fine needle aspiration (FNA) in the diagnosis of mediastinal and lung lesions is the endobronchial ultrasound (EBUS)-guided FNA. In this study, we describe five cases which had a discrepancy between on-site evaluation and final diagnosis, or a diagnostic dilemma when rendering the preliminary diagnosis, in order to illustrate some of the diagnostic difficulties and pitfalls that can occur in EBUS FNA.

METHODS

A total of five EBUS FNA cases from five patients were identified in our records with a discrepancy between the rapid on-site evaluation (ROSE) and final diagnosis, or that addressed a diagnostic dilemma. All of the cases had histological confirmation or follow-up. The cytomorphology in the direct smears, cell block, and immunohistochemical stains were reviewed, along with the clinical history and other available information.

RESULTS

Two cases were identified with a nondefinitive diagnosis at ROSE that were later diagnosed as malignant (metastatic signet-ring cell adenocarcinoma and metastatic renal cell carcinoma (RCC)) on the final cytological diagnosis. Three additional cases were identified with a ROSE and final diagnosis of malignant (large cell neuroendocrine carcinoma (LCNEC) and two squamous cell carcinomas), but raised important diagnostic dilemmas. These cases highlight the importance of recognizing discohesive malignant cells and bland neoplasms on EBUS FNA, which may lead to a negative or a nondefinitive preliminary diagnosis. Neuroendocrine tumors can also be difficult due to the wide range of entities in the differential diagnosis, including benign lymphocytes, lymphomas, small and nonsmall cell carcinomas, and the lack of immunohistochemical stains at the time of ROSE. Finally, the background material in EBUS FNAs may be misleading and unrelated to the cells of interest.

CONCLUSIONS

This study illustrates the cytomorphology of five EBUS FNA cases that address some of the diagnostic challenges witnessed while examining these specimens during ROSE. Many of the difficulties faced can be attributed to the baseline cellularity of the aspirates, the bronchial contamination, the difficulty identifying neoplasms with bland cytology, the wide spectrum of diseases that can occur in the mediastinum with overlapping cytomorphologic features, the mismatch between the background material and the cell populations present, and the overall unfamiliarity with these types of specimens.

Fine needle aspiration of renal cortical lesions in adults

The role of fine needle aspiration (FNA) biopsy of renal cortical lesions was controversial in the past because the result of the FNA did not affect clinical management. All renal cortical lesions, except metastasis, were subject to surgical resection. However, with the advances in neoadjuvant targeted therapies, knowledge of the renal cortical tumor histological subtype is critical for tailoring clinical trials and follow-up strategies. At present, there are clinical trials involving the use of novel kinase inhibitors for conventional (clear cell) and papillary renal cell carcinoma. We studied 143 consecutive cases of renal cortical lesions, evaluated after radical or partial nephrectomies over a 2-year period. An air-dried smear and a Thinprep® slide were prepared in all cases. The slides were Diff-Quick and Papanicolaou stained, respectively. The cytology specimens were reviewed and the results were then compared with the histologic diagnosis. Cytology was highly accurate to diagnose conventional RCC, while the accuracy for papillary RCC, chromophobe RCC, and papillary urothelial carcinoma was much lower. Our results indicate that ancillary studies might have an important role in the subclassification of renal cortical neoplasms for targeted treatment.

Biopsy of a renal mass: where are we now?

PURPOSE OF REVIEW

To review the most recent literature concerning renal mass biopsy with special consideration to three points: variation in results related to the standard used as comparison, biopsy in small renal masses (up to 4 cm in diameter) and the case for nondiagnostic biopsy.

RECENT FINDINGS

The overall rate of failed and indeterminate biopsies shows a trend for improvement. However, selection bias and the lack of a uniform index test for comparison preclude a definitive statement. Fine-needle aspiration may equal results of core biopsy, but its role in the diagnostic algorithm is not yet defined. In-vivo accuracy decreases in small renal masses with the same limitations exposed for the overall literature on renal mass biopsy. When nondiagnostic biopsies are considered, there is a need for standardization of the nomenclature in order to compare results. Re-biopsies or surgery after a nondiagnostic biopsy shows malignancy in up to 75% of the cases of renal cell carcinoma.

SUMMARY

There is a trend in increasing interest and accuracy on the subject of percutaneous biopsy of renal masses as well as a decreasing trend in the rate of nondiagnostic biopsies. In the small renal masses, most likely to be benign, a diagnostic percutaneous biopsy may have a definitive role. However, the higher rate of nondiagnostic results in this population calls for prospective studies with standard definitions and when possible homogenous index test to properly assess the diagnostic performance of the biopsy.

EUS-guided FNA aspiration of kidney masses: a multicenter U.S. experience

BACKGROUND

Tissue sampling of renal lesions is traditionally performed with percutaneous US or CT guidance. To date, only 3 known cases of EUS-guided FNA (EUS-FNA) of a renal mass have been reported.

OBJECTIVE

To describe a multicenter experience with the indications, yield, and complications from attempted EUS-FNA of a kidney mass.

DESIGN

Retrospective case series.

SETTING

Six tertiary referral hospitals in the United States.

PATIENTS

Consecutive subjects undergoing attempted EUS-FNA of a kidney mass. Endosonographers at 15 other teaching hospitals were contacted regarding EUS findings and follow-up of any EUS-guided renal biopsies previously attempted or considered at that institution.

INTERVENTIONS

EUS-FNA of a kidney mass.

MAIN OUTCOME MEASUREMENTS

Biopsy indications, yield, diagnosis, and complications.

RESULTS

Fifteen procedures in 15 patients (9 men; median age 67 years) were performed at 6 (37%) of 16 hospitals (Indiana University plus 15 other hospitals). Kidney masses (median diameter 32 mm; range 11-60 mm) were located in the upper (n = 12) and lower (n = 3) poles of the left (n = 10) and right (n = 5) kidneys, respectively. Initial mass detection was by previous imaging in 13 (87%) patients or by EUS in 2 (13%) patients. Results of EUS-FNA (median 3 passes; range 2-4 passes) in 13 (87%) procedures were diagnostic of (n = 7) or highly suspicious for (n = 1) renal cell carcinoma (RCC), atypical cells (n = 2), oncocytoma (n = 1), benign cyst (n = 1), and nondiagnostic (n = 1). No complications were encountered. Surgical resection confirmed RCC in 7 patients in whom preoperative EUS-FNA demonstrated RCC (n = 5) or oncocytoma (n = 1) or was not performed (n = 1).

LIMITATIONS

Retrospective series, small number of patients.

CONCLUSIONS

EUS-FNA of renal masses is rarely performed at the U.S. teaching hospitals surveyed. This technique appears safe and feasible and should be considered when results would affect patient management.

[Renal mass biopsy: results and safety in 2009]

The role of renal mass biopsies has been limited by suboptimal results in terms of diagnostic reliability, and their scant repercussion upon therapeutic decision taking. Recently, however, renal mass biopsies have generated renewed interest among urologists, as a result of the increased incidence of renal tumors, the introduction of new management options, and advances in histological diagnosis. A review has been made, based on a PubMed search of the most relevant publications on renal tumor biopsies in recent years. The most recent clinical studies reveal a high degree of diagnostic reliability in differentiating malignancy, histological type and grade in percutaneous biopsies of renal tumors, with a low rate of associated complications. However, routine use of the technique remains controversial, and its indications limited, due to the scant capacity of the renal biopsy findings to modify treatment decision.

Contemporary results of percutaneous biopsy of 100 small renal masses: a single center experience

PURPOSE

Percutaneous biopsy of small renal tumors has not been historically performed because of concern about complications and accuracy. We reviewed our experience with percutaneous needle biopsy of small renal masses to assess the safety and accuracy of the procedure, the potential predictors of a diagnostic result and the role of biopsy in clinical decision making.

MATERIALS AND METHODS

A total of 100 percutaneous needle biopsies of renal masses less than 4 cm were performed between January 2000 and May 2007 with 18 gauge needles and a coaxial technique under ultrasound and/or computerized tomography guidance. A retrospective chart review was performed to document the complication rate and the ability to obtain sufficient tissue for diagnosis. Tumor size, tumor type (solid vs cystic), image guidance, biopsy number and core length were assessed for the ability to predict a diagnostic biopsy.

RESULTS

No tumor seeding or significant bleeding was observed. Of the core biopsies 84 (84%) were diagnostic for a malignant (66) or a benign (18) tumor. Larger tumor size and a solid pattern were significant predictors of a diagnostic result. Histological subtyping and grading were possible on core biopsies in 93% and 68% of renal cell carcinomas, respectively. A total of 20 patients underwent surgery after a diagnostic biopsy. The histological concordance of biopsies and surgical specimens was 100%.

CONCLUSIONS

Percutaneous needle biopsy of renal masses less than 4 cm is safe and provides adequate tissue for diagnosis in most cases. Larger tumor size and a solid pattern are significant predictors of a successful biopsy. Renal tumor biopsy decreases the rate of unnecessary surgery for benign tumors and can assist the clinician with treatment decision making, especially in elderly and unfit patients.

[Usefulness of cytology in diagnosis and management of renal and perirenal tumors in adults]

INTRODUCTION

The use more and more extended of tumorectomy, partial nephrectomy and nonsurgical treatments of renal tumors has supposed a renewed interest in the diagnosis use of cytology. Whether during preoperative period, through the puncture aspiration with fine needle (PAAF), or during the intraoperative analysis, the cytology offers the possibility of a specific morphologic diagnosis. In this revision the information concerning the diagnostic value of the cytology in renal tumors is updated.

MATERIAL AND METHODS

The references related to renal masses cytological descriptions has been reviewed. For this purpose we have searched both with computer in Medline data base and also manually. In the same way we include authors experience as much in the PAAF of these lesions as in the intraoperative use of the cytology.

RESULTS

Between neoplasias with more cytological typical presentation are the clear cell renal and papillary carcinomas. The chromophobe and oncocytoma can show similarities, although the accumulated experience in the last years reflects that its differentiation is possible in most of the cases. For the diagnosis of angiomyolipoma, urothelial carcinoma and kidney metastasis, the clinical and image information are of great interest for the pathologist. The integration of these data usually allows a specific diagnosis.

CONCLUSION

Generally, cytology reflects with accuracy the histological characteristics of renal neoplasias, allowing in many cases a specific diagnosis. We consider much appropriated the use of cytology, due to the more and more frequent situation of "incidentaloma". The PAAF minimum invasive nature and the possibility of performing a fast cytological analysis during intraoperative studies offer important information for the therapeutic management of these patients.

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.

Fine-needle aspiration of renal angiomyolipoma: a report of four cases

OBJECTIVE

Renal angiomyolipoma is an uncommon benign tumour composed of smooth muscle cells, blood vessels and adipose tissue. The cytological findings of this tumour are described.

METHODS

A retrospective analysis of four cases of angiomyolipoma diagnosed on fine-needle aspiration cytology (FNAC) during the period 1998-2004 was carried out. All the aspirations were carried out under ultrasonographic image guidance.

RESULTS

Smears from three cases showed oval- to spindle-shaped tumour cells, cohesive stromal fragments embedded in adipose tissue and branching blood vessels in a haemorrhagic background. No mitotic figures were seen. Smears from one case showed adipose tissue and blood. In this case, sections from the cell block showed mature adipose tissue and small blood vessels.

CONCLUSION

The diagnosis of angiomyolipoma can be made by FNAC under image guidance and a cell block may be quite helpful in making a correct diagnosis. It is important to establish a correct preoperative diagnosis as treatment of these tumours is conservative and this obviates the need for total nephrectomy.

Metastases to the kidney: eleven cases diagnosed by aspiration biopsy with histological correlation

Metastases to the kidney from extrarenal primary tumors are uncommon and may mimic renal-cell carcinoma clinically when presenting as a single mass with hematuria. Fine-needle aspiration biopsy (FNAB) is a useful diagnostic method for the evaluation of primary renal tumors. Only a few studies have investigated the value of cytological evaluation of secondary renal tumors. We report our experience with these tumors. Eleven cases of extrarenal primary tumors metastatic to the kidney, diagnosed by aspiration biopsy with histological correlation, are discussed. The diagnosis of metastatic disease to the kidney was accurately made by aspiration biopsy. Knowledge of the patients' history, histological correlation with the primary tumor, and the radiological characteristics of the renal masses were helpful in achieving a correct diagnosis. FNA cytology (FNAC) is an accurate method for the diagnosis of tumors metastatic to the kidney. Distinction between primary and secondary tumors of the kidney is crucial to guide management and prevent unnecessary surgery.

Distinguishing Primary and Metastatic Conventional Renal Cell Carcinoma From Other Malignant Neoplasms in Fine-Needle Aspiration Biopsy Specimens

Context.—Differentiation of conventional renal cell carcinoma from other malignant neoplasms can be difficult, particularly with the limited sampling in fine-needle aspiration biopsies. Many studies have discussed the features of renal cell carcinoma in fine-needle aspiration biopsy specimens, but the significance of the cytologic features is not known.

Objective.—To define the significant cytologic findings that aid in differentiating renal cell carcinoma from other malignant neoplasms in fine-needle aspiration biopsy specimens.

Design.—Fine-needle aspiration biopsies from 35 patients with proven primary or metastatic conventional renal cell carcinoma and from 145 patients with proven primary or metastatic non–renal cell carcinoma malignant neoplasms were assessed for the presence or absence of the following cytologic features: the heterogeneous cell population, hemosiderin deposits, small cytoplasmic vacuoles, large cytoplasmic vacuoles, low nuclear-cytoplasmic ratio, prominent nucleoli, intranuclear inclusions, irregular nuclear membranes, and smooth nuclear membranes. Statistical analysis was performed to identify the features significant in distinguishing conventional renal cell carcinoma from non–renal cell carcinoma malignancies.

Results.—The presence of the heterogeneous cell population, hemosiderin deposits, small cytoplasmic vacuoles, and low nuclear-cytoplasmic ratio were each highly significant in conventional renal cell carcinoma when compared with non–renal cell carcinoma malignant neoplasms (P &lt; .001) using univariate exact analysis. Features that were identified as being predictive of conventional renal cell carcinoma using multivariable logistic regression analysis included heterogeneous cell population, small cytoplasmic vacuoles, and hemosiderin deposits (P &lt; .05).

Conclusions.—The presence of the heterogeneous cell population, small cytoplasmic vacuoles, hemosiderin deposits, and a low nuclear-cytoplasmic ratio aids in differentiating conventional renal cell carcinoma from other malignant neoplasms, including morphologically similar entities such as hepatocellular carcinoma, in fine-needle aspiration biopsy specimens.

Utility of CD10 and RCCma in the diagnosis of metastatic conventional renal-cell adenocarcinoma by fine-needle aspiration biopsy

The cytologic diagnosis of primary conventional renal-cell adenocarcinoma (cRCC) is usually straightforward; however, metastatic cRCC must be distinguished from a variety of neoplasms with clear-cell features. CD10, a cell membrane-associated neutral endopeptidase, and renal-cell carcinoma marker (RCCma), an antibody against human proximal tubular brush border antigen, have recently been shown to be useful in the diagnosis of cRCC. We compared CD10 and RCCma in cell block material from fine-needle aspiration biopsies (FNABs) to assess their utility in the diagnosis of metastatic cRCC, in cytologic specimens. Seven primary and sixteen metastatic cRCCs were immunostained with CD10 and RCCma. The immunoreactivity results were compared with those of a variety of neoplasms originating from other sites such as the liver, lungs, breast, and the gastrointestinal tract. The sensitivity and specificity of CD10 for cRCC were 100% and 59%, respectively. The sensitivity and specificity of RCCma for cRCC were 35% and 100%, respectively. We conclude that CD10 has limited value in confirming the diagnosis of cRCC because of its low specificity. RCCma, when positive, is highly specific for cRCC, but its low sensitivity hinders its diagnostic usefulness.

Fine-needle aspiration of renal angiomyolipoma: Cytological findings and diagnostic pitfalls in a series of five cases

Diagnosis of renal angiomyolipoma (AML) by fine-needle aspiration (FNA) may be difficult because cytological and radiological findings sometimes overlap with renal cell carcinoma (RCC) and liposarcoma. Five FNAs of AMLs were studied. Epithelioid and spindle stromal cells were arranged in loosely cohesive clusters and singly. The chromatin was evenly distributed and bland. Occasionally nuclear atypia was identified. Nuclei were oval to elongated, nucleoli were inconspicuous or absent, naked nuclei were present in three specimens, and intranuclear inclusions were present in two specimens. The cytoplasm was delicate and sometimes finely vacuolated. Adipose tissue was observed in two specimens. Thick-walled vessels, mitoses, and necrosis were absent. Corresponding surgical material showed typical features of AML. In FNA, bland chromatin and inconspicuous nucleoli distinguish renal AML from RCC and liposarcoma. Adipose tissue is not universally present. Cellular atypia in conjunction with overlapping radiological findings with RCC and liposarcoma are potential diagnostic pitfalls. Immunocytochemical (ICC) stains may elucidate the correct diagnosis.

Distribution of subtypes of metastatic renal-cell carcinoma: correlating findings of fine-needle aspiration biopsy and surgical pathology

Clear-cell (CRCC), papillary (PRCC), and chromophobe (CHRCC) renal-cell carcinoma (RCC) are the three most frequent subtypes of RCC. The rate and distribution of their metastatic lesions have not been well studied in cytopathological materials. Sixty-two fine-needle aspiration biopsy cases of metastatic RCC were studied and correlated with surgical pathology of RCCs with and without metastasis. Special stains for glycogen and immunostaining for cytokeratins, vimentin epithelial membrane antigen (EMA), and carcinoembryonic antigens, and electron microscopic studies were performed. Fifty-nine cases of CRCC and three of PRCC subtypes were retrieved from the cytopathology files at the Ottawa Hospital in a period of 10 years. Of these cases, 10 metastatic CRCC and one metastatic PRCC were diagnosed prior to the diagnosis of the primary tumor. CHRCC and sarcomatoid RCC were not represented in cytopathological specimens. CRCC displayed characteristic filmy cytoplasm and nuclei with prominent nucleoli. PRCC was characterized by dense cytoplasm, large nuclei with prominent nucleoli, and papillary architectures. In addition, all RCCs were characterized by the presence of glycogen and the absence of mucin by using histochemical techniques and electron microscopic studies and positive reactivity for cytokeratins (CK) and vimentin (VIM). In the same period, there were a total of 380 patients with RCC divided into 310 CRCCs, 55 PRCCs, and 15 CHRCCs associated with metastases in 142, 9, and 1 case, respectively. CRCC is by far the most common subtype found in metastases sampled in cytopathology. PRCC, CHRCC, and sarcomatoid RCC were underrepresented. Awareness of this propensity of RCC and the characteristic cytopathological, histochemical, immunohistochemical, and ultrastructural features are helpful in the diagnosis of metastatic RCC.

Misinterpretation of normal cellular elements in fine-needle aspiration biopsy specimens: observations from the College of American Pathologists Interlaboratory Comparison Program in Non-Gynecologic Cytopathology

CONTEXT

The College of American Pathologists Interlaboratory Comparison Program in Non-Gynecologic Cytopathology is a popular educational program for nongynecologic cytology, with 1018 participating laboratories by the end of 2000. Data generated from this program allow tracking pathologist performance in a wide variety of laboratory practices.

OBJECTIVE

To review performance of participating pathologists in making patient diagnoses with fine-needle aspiration biopsy specimens, with particular interest in the false neoplastic diagnoses (both benign and malignant neoplasms) that were submitted for benign aspirates containing only normal cellular components.

DESIGN

We reviewed the diagnoses made from 1998 through 2000 by participating pathologists through the use of glass slides containing benign fine-needle aspiration biopsy specimens of the liver, kidney, pancreas, and salivary gland that contained only normal cellular components.

RESULTS

The false neoplastic rate for kidney (60%) was the highest, followed by liver (37%), pancreas (10%), and salivary gland (6%). These rates are much higher than what has previously been reported in the literature.

CONCLUSIONS

This study illustrates that normal cellular elements are a significant pitfall for overinterpretation of fine-needle aspiration biopsy specimens.