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

Risk of malignancy in renal biopsy: A review

The risks of malignancy for cytologic categories in renal biopsy specimens differ from the risks in most other sites. There are obvious areas in which cytopathologists can do better at classifying these cases, and the routine use of immunohistochemistry and core-needle biopsy may improve the accuracy of the classification of these specimens.

Radiogenomics in Renal Cancer Management-Current Evidence and Future Prospects

Renal cancer management is challenging from diagnosis to treatment and follow-up. In cases of small renal masses and cystic lesions the differential diagnosis of benign or malignant tissues has potential pitfalls when imaging or even renal biopsy is applied. The recent artificial intelligence, imaging techniques, and genomics advancements have the ability to help clinicians set the stratification risk, treatment selection, follow-up strategy, and prognosis of the disease. The combination of radiomics features and genomics data has achieved good results but is currently limited by the retrospective design and the small number of patients included in clinical trials. The road ahead for radiogenomics is open to new, well-designed prospective studies, with large cohorts of patients required to validate previously obtained results and enter clinical practice.

Accuracy of Subclassification and Grading of Renal Tumors on Fine Needle Aspiration Cytology Alone

BACKGROUND

Fine needle aspiration (FNA) of renal masses can distinguish between benign and malignant neoplasms in 73-94% of cases. Previous studies suggested the correct subclassification of renal cell carcinomas (RCCs) by cytomorphology can be achieved in up to 80% of cases. However, as RCCs become increasingly subclassified by molecular signatures, correct subclassification based on cytology alone is increasingly difficult.

DESIGN

Two FNA passes (2 stained with Diff-Quik® and 2 with the Papanicolaou method) were performed on all fresh nephrectomy specimens for a 1-year period. There were 30 cases in this study, with 29 primary renal tumors and 1 case of metastatic lung adenocarcinoma. Each case was assigned a random number and came with 2 slides (1 from each staining method). Eight cytopathologists were asked to provide a diagnosis and the World Health Organization/International Society of Urological Pathology (WHO/ISUP) grading if applicable. Fleiss' Kappa and Cohen's Kappa equations were used to look at inter-rater variability.

RESULTS

When compared to the surgical pathology diagnosis, the average percent correct diagnosis for all cytopathologist was 35%. Chromophobe RCCs had the best average percent accuracy at 72% followed by clearcell RCC at 48%. Average accuracy for grading RCCs was 40%. Inter-rater variability among the cytopathologists for all RCC diagnoses was fair with a Fleiss' Kappa coefficient of 0.28. For the WHO/ISUP grade, the weighted coefficient for each pathologist ranged from 0.11 to 0.45, ranging from fair to moderate, respectively.

CONCLUSIONS

Renal tumors are difficult to classify on cytopathology alone. Core needle biopsy and ancillary studies are necessary if diagnosis will change management.

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.

Accuracy and safety of ultrasound-guided percutaneous needle core biopsy of renal masses: A single center experience in China

Our aim is to determine the sufficiency, accuracy, and safety of ultrasound-guided percutaneous needle core biopsy of renal masses in Chinese patients.Patients who had undergone ultrasound-guided needle core renal mass biopsy from June 2012 to June 2016 at West China Hospital, China were retrospectively reviewed. The information obtained included demographics, mass-related parameters, biopsy indications, technique, complications, pathologic results, and follow-up. Concordance of surgical resection pathology and follow-up data were assessed.Renal mass biopsies were performed in 106 patients. Thirty-nine (36.8%) were asymptomatic. The male/female ratio was 60/46, with a median age of 49.5 years. Median mass size was 8.1 cm (range 1.8-20). Biopsy was performed through a 16-gauge needle, with median cores of 2 taken (range 1-5). Only one significant biopsy-related complication (hemorrhage requiring transfusion) was encountered. An adequate tissue sample was obtained in 97.2% (103/106) of biopsies. Eighty-seven biopsies (82.1%) showed malignant neoplasms, 16 (15.1%) yielded benignity, and 3 (2.8%) were nondiagnostic. After biopsy, 46 patients (43.4%) underwent surgery. Compared with the subsequent mass resection pathology, the biopsy diagnoses were identical in 43 cases. The accuracy rate of biopsy distinguishing malignant from benign lesions was 99.1%, and the rate for determining tumor histological type (excluding the nondiagnostic biopsies) was 95.1%. The sensitivity and specificity in detecting malignancy were 98.9% and 100%, respectively.In several situations, there is still a role for biopsy before intervention. Percutaneous needle core biopsy under ultrasonography guidance is highly accurate and safe, and can determine the proper management of undefinable masses.

Management of renal cell carcinoma presenting as inflammatory renal mass

Introduction:

Renal cell carcinoma (RCC) can have a wide spectrum of clinical presentations. In the immunocompromised patient fever and an inflammatory renal mass can harbor RCC.

Materials and Methods:

We reviewed the charts of patients who were managed at our department during 1998-2008 as renal abscess or perinephric collection. Renal ultrasound and subsequently abdominal CT was done. Medical treatment in the form of antibiotics, control of diabetes and drainage was done. Percutaneous or open biopsy, pus cultures, and histopathology were used to guide therapy. With a positive biopsy radical surgery was considered, while with a negative result a follow up CT was planned.

Results:

We identified 11 patients who had high fever, a renal abscess (in 4), or a suspicious mass with perinephric collection (in 7), and were eventually diagnosed to have RCC. Mean patient age was 66 years (53-82). 8 patients had uncontrolled diabetes. Five patients had a percutaneous drainage biopsy; of those two had a positive histopathology, the other three patients had a persistent enhancing mass on follow-up CT scan. Of this group three patients underwent radical nephrectomy. Another five patients had open drainage and biopsy, four patients had very poor performance status. One patient had radical surgery without the need for biopsy.

Conclusion:

In the elderly and immunocompromised patient renal cancer may present as renal abscess or perinephric collection. Histopathology and bacteriology are the mainstay of diagnosis. If biopsy was negative, follow up should include a CT scan to exclude any residual enhancing masses.