Percutaneous biopsy for the diagnosis, risk stratification, and molecular profiling of neuroblastoma: A single-center retrospective study.

PURPOSE: To determine whether percutaneous core needle biopsy (PCNB) is adequate for the diagnosis and full molecular characterization of newly diagnosed neuroblastoma. MATERIALS AND METHODS: Patients with newly diagnosed neuroblastoma who underwent PCNB in interventional radiology at a single center over a 5-year period were included. Pre-procedure imaging and procedure details were reviewed. Rates of diagnostic success and sufficiency for International Neuroblastoma Pathology Classification (INPC), risk stratification, and evaluation of genomic markers utilized in the Children's Oncology Group risk stratification, and status of the anaplastic lymphoma kinase (ALK) gene were assessed. RESULTS: Thirty-five patients (13 females, median age 2.4 years [interquartile range, IQR: 0.9-4.4] and median weight 12.4 kg [IQR: 9.6-18]) were included. Most had International Neuroblastoma Risk Group Stage M disease (n = 22, 63%). Median longest axis of tumor target was 8.8 cm [IQR: 6.1-12]. A 16-gauge biopsy instrument was most often used (n = 20, 57%), with a median of 20 cores [IQR: 13-23] obtained. Twenty-five specimens were assessed for adequacy, and 14 procedures utilized contrast-enhanced ultrasound guidance. There were two post-procedure bleeds (5.7%). Thirty-four of 35 procedures (97%) were sufficient for histopathologic diagnosis and risk stratification, 94% (n = 32) were sufficient for INPC, and 85% (n = 29) were sufficient for complete molecular characterization, including ALK testing. Biologic information was otherwise obtained from bone marrow (4/34, 12%) or surgery (1/34, 2.9%). The number of cores did not differ between patients with sufficient versus insufficient biopsies. CONCLUSION: In this study, obtaining multiple cores with PCNB resulted in a high rate of diagnosis and successful molecular profiling for neuroblastoma.

Image-guided core-needle or surgical biopsy for neuroblastoma diagnosis in children: A systematic review and meta-analysis from the International Society of Pediatric Surgical Oncology (IPSO).

BACKGROUND: Image-guided core-needle biopsy (IGCNB) is a widely used and valuable clinical tool for tissue diagnosis of pediatric neuroblastoma. However, open surgical biopsy remains common practice even if children undergo more invasive and painful procedures. This review aims to determine the diagnostic accuracy and safety of IGCNBs in pediatric patients with neuroblastoma. METHODS: We conducted a systematic review of peer-reviewed original articles published between 1980 and 2023, by searching "pediatric oncology," "biopsy," "interventional radiology," and "neuroblastoma." Exclusion criteria were patients older than 18 years, studies concerning non-neurogenic tumors, case reports, and language other than English. Both the systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. RESULTS: A total of 533 abstracts articles were analyzed. Of these, eight retrospective studies met inclusion criteria (490 infants, 270 surgical biopsies [SB], 220 image-guided biopsies). Tissue adequacy for primary diagnosis (SB: n = 265, 98%; IGCNB: n = 199, 90%; p = .1) and biological characterization (SB: n = 186, 95%; IGCNB: n = 109, 89%; p = .15) was similar with both biopsy techniques, while intraoperative transfusion rate (SB: n = 51, 22%; IGCNB: n = 12, 6%; p = .0002) and complications (%) (SB: n = 58, 21%; IGCNB: n = 14, 6%; p = .005) were higher with surgical biopsy. Length of stay was similar in both groups; however, no additional data about concurrent diagnostic or treatment procedures were available in the analyzed studies. CONCLUSIONS: IGCNB is a safe and effective strategic approach for diagnostic workup of NB and should be considered in preferance to SB wherever possible.

Safety and histopathologic yield of percutaneous CT-guided biopsies of the skull base, orbit, and calvarium.

PURPOSE: Although CT-guided biopsies of the calvarium, skull base, and orbit are commonly performed, the best approaches, efficacy, and safety of such procedures remain scantly described in the literature. This retrospective review of percutaneous biopsies illustrates several approaches to challenging biopsy targets and provides a review of procedural planning considerations and histopathologic yield. METHODS: A retrospective review of CT-guided biopsies of the skull base, calvarium, and orbit between 1/1/2010 and 10/30/2020 was conducted. Patient demographics and procedural factors were recorded, including lesion size and location, biopsy approach, and needle gauge. Outcomes were also noted, including CT dose length product, complications, and histopathologic yield. RESULTS: Sixty-one CT-guided biopsies were included in the final analysis: 34 skull base, 23 calvarial, and 4 orbital lesions. The initial diagnostic yield was 32/34 (94%) for skull base lesions, with one false-negative and one non-diagnostic sample. Twenty-one of twenty-three (91%) biopsies in the calvarium were initially diagnostic, with one false-negative and one non-diagnostic sample. In the orbit, 4/4 biopsies were diagnostic. The total complication rate for the cohort was 4/61 (6.6%). Three complications were reported in skull base procedures (2 immediate and 1 delayed). A single complication was reported in a calvarial biopsy, and no complications were reported in orbital biopsies. CONCLUSION: Percutaneous CT-guided core needle biopsies can be performed safely and with a high diagnostic yield for lesions in the skull base, calvarium, and orbit.

Percutaneous core needle biopsy of neuroblastoma in the pediatric population: what have we learned in the last decade.

INTRODUCTION: Historically, neuroblastoma has been diagnosed by surgical open biopsy (SB). In recent decades, core needle biopsy (CNB) has replaced surgical biopsy due to its safe and adequate method of obtaining tissue diagnosis. AIM: Our study aimed to assess the effectiveness of CNB in obtaining tissue diagnosis for neuroblastoma and evaluate its safety profile in terms of post-operative complications, in comparison to SB. METHODS: A retrospective cohort study, including all patients younger than 18 years who were diagnosed with neuroblastoma from 2012 until 2022 in a single tertiary medical center. Patients' demographics, tumor size and location, pathological results, and clinical outcomes were collected. RESULTS: 79 patients were included in our study: 35 biopsies were obtained using image-guided CNB and 44 using SB. Patients' and tumor characteristics including age, gender, tumor volume, and stage were similar in both groups. The biopsy adequacy rate in the CNB group was 91% and 3 patients in this group underwent repeated biopsy. The safety profile in the CNB group was similar to the SB group. CONCLUSIONS: CNB is a safe method and should be considered the first choice for obtaining tissue diagnosis when feasible due to its high adequacy in terms of tumor histopathological features.

Percutaneous biopsy of musculoskeletal tumors and the potential for needle tract seeding: technical considerations, current controversies, and outcomes.

Multidisciplinary communication and planning between the musculoskeletal radiologist and orthopedic oncologist are essential for proper biopsy planning when a primary musculoskeletal malignancy is suspected. Image-guided percutaneous biopsy allows for real-time visualization of the biopsy needle and surrounding structures, combining high diagnostic accuracy with safety and cost-effectiveness. However, determining a surgically optimal biopsy trajectory for a mass can be technically challenging due to critical surrounding anatomy or challenging needle approach angles. Inappropriately placed biopsies can have serious repercussions on patient function and oncological survival. The potential for needle tract seeding and local recurrence after biopsy of sarcoma has been central to the debate regarding the need for excision of the biopsy tract. This multidisciplinary review highlights current controversies in the field, including the issue of core needle biopsy tracts and their excision, technical considerations and advances in image-guidance in the setting of challenging biopsies, advances in histopathological diagnostics with implications for targeted therapy in sarcoma, as well as surgical and oncological outcomes after needle tract biopsy.

Cervical spine tenosynovial giant cell tumor involving the atlantoaxial joint in a pediatric patient with medulloblastoma.

Tenosynovial giant cell tumor (TGCT) is a benign condition that arises from tendon sheaths, synovium, or bursae and is classified according to the site of involvement (intra-articular versus extra-articular) and pattern of growth (localized versus diffuse). The diffuse form tends to present as peri-articular masses and are locally aggressive. It usually presents as a mono-articular process affecting larger joints. Spinal involvement is extremely rare, particularly the cervical spine. In this case report, we present a pediatric case of spinal TGCT involving the C1-C2 joint which was incidentally detected in a 13-year-old girl undergoing surveillance for medulloblastoma recurrence. Although spinal TGCT is a benign condition, it remains a diagnostic challenge, which specific to our case can raise the concern for malignancy or metastasis. We also described a percutaneous biopsy approach using a spring-loaded blunt tip coaxial needle to avoid inadvertent vascular injury. The imaging features of spinal TGCT and biopsy approach for atlantoaxial lesion are discussed together with a comprehensive review of the literature.

Computed tomography-guided percutaneous biopsy for retroperitoneal lesions: a systematic review and meta-analysis.

The aim of this study is to perform a systematic review and meta-analysis of published studies to evaluate the efficacy and safety of computed tomography (CT)-guided percutaneous biopsy for retroperitoneal lesions. PubMed and the Cochrane Library were searched for English-language articles published up to October 2021 and reporting findings about patients with retroperitoneal lesions who underwent CT-guided percutaneous biopsy. The outcome measures assessed in this systematic review and meta-analysis are accuracy, false negative rate, and rate of minor and major complications. Heterogeneity among studies was evaluated by testing Cochran's Q and the inconsistency index statistics. Seven studies published from 1975 to 2021 were selected for the analysis of accuracy, false negative rates, and rate of major and minor complications. The pooled accuracy of CT-guided percutaneous biopsy for retroperitoneal lesions was 93.6% [95% confidence interval (CI), 88.1-96.6%], with high heterogeneity. The pooled false negative rate was 6.3% (95% CI, 3.3-11.7%) with high heterogeneity. Pooled rates of minor and major complications were 3.7% (95% CI, 1.6-8.6%) with moderate heterogeneity and 0.7% (95% CI, 0.4-1.1%) with low heterogeneity, respectively. CT-guided percutaneous biopsy for retroperitoneal lesions has been reported to have high accuracy with a limited rate of major complications.

Percutaneous transluminal forceps biopsy with an adjustable curved sheath for obstructive jaundice.

PURPOSE: To evaluate the feasibility and safety of percutaneous transluminal forceps biopsy (PTFB) with an adjustable curved sheath in patients with obstructive jaundice. MATERIAL AND METHODS: Forty-two patients who underwent PTFB with an adjustable curved sheath were analyzed retrospectively. Sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV) and accuracy were calculated for all populations and in different situations. Technical success and safety were evaluated. RESULTS: The technical success rate was 100%. Thirty-five of 42 cases were diagnosed malignant diseases, the sensitivity of PTFB with an adjustable curved sheath was 74.29% (26/35), the specificity was 100%, the positive predictive value was 100%, the negative predictive value was 43.75% (7/16), and the accuracy rate was 78.57% (33/42). There was a better sensitivity for bile duct malignancies when compared with non-bile duct malignancies (p = 0.012). No statistical difference was found in the sensitivity of the upper part of the biliary tree and the lower part of the biliary tree, and none in the sensitivity of different approaches (left vs. right). The complication rate was 11.90%, and no serious complications were observed. CONCLUSIONS: PTFB with an adjustable curved sheath is an effective and safe technique, without being limited by approaches and obstruction sites.

The morbidity of open tumor biopsy for intraabdominal neoplasms in pediatric patients.

PURPOSE: Tumor biopsy is often essential for diagnosis and management of intraabdominal neoplasms found in children. Open surgical biopsy is the traditional approach used to obtain an adequate tissue sample to guide further therapy, but image-guided percutaneous core-needle biopsy is being used more often due to concerns about the morbidity of open biopsy. We used a national database to evaluate the morbidity associated with open intraabdominal tumor biopsy. METHODS: We identified all patients undergoing laparotomy with tumor biopsy in the National Surgical Quality Improvement Project-Pediatric (NSQIP-P) database from 2012 to 2018 and measured the frequency of complications in the 30 days postoperatively. We tested associations between patient characteristics and outcomes to identify risk factors for complications. RESULTS: We identified 454 patients undergoing laparotomy for biopsy of an intraabdominal neoplasm. Median postoperative hospital stay was 7 days (IQR 4-12) and operative time was 117 min (IQR 84-172). The overall complication rate was 12.1%, with post-operative infection (6%) and bleeding (4.2%) being the most common complications. Several patient characteristics were associated with bleeding, but the only significant association on multivariable analysis was underlying hematologic disorder. CONCLUSION: Open abdominal surgery for pediatric intraabdominal tumor biopsy is accompanied by significant morbidity. Postoperative infection was the most common complication, which can delay initiation of further therapy, especially chemotherapy. These findings support the need to prospectively compare percutaneous image-guided core-needle biopsy to open biopsy as a way to minimize risk and optimize outcomes for this vulnerable population.

Functional and metabolic imaging in transthoracic biopsies guided by computed tomography.

OBJECTIVES: CT-guided biopsy of indeterminate lung lesions sometimes provides insufficient histological results due to tumor necrosis. Functional and metabolic methods such as DWI-MR and PET-CT may help by directing sample collection to a lesion area of greater biological representativeness. The objective is to evaluate the histopathological results based on findings on ADC and SUV levels in lung lesions suspected for primary cancer. METHODS: Tissue samples were evaluated after undergoing biopsies guided by either DWI-MR or PET-CT findings. In each patient, sample collection from two lesion areas was guided by local ADC and SUV. Values were used to define areas of low vs. high suspicion for cancer. RESULTS: Patients who underwent DWI-MR had median lesion size of 78.0 mm. Areas of higher suspicion (HSA) had a median ADC of 1.1 × 10-3 mm2/s, while areas of lower suspicion (LSA) had median ADC of 1.8 × 10-3 mm2/s (p = 0.0001). All HSA samples and 71.43% of LSA samples were positive for cancer (p = 0.0184). Patients who performed PET-CT had median lesion size of 61.0 mm. Median SUV was 7.1 for HSA and 3.9 for LSA (p = 0.0002). Positivity for cancer was observed in 76.9% of samples for both HSA and LSA (p = 0.0522). CONCLUSION: Use of DWI-MR and PET-CT showed that tumors are functional and metabolically heterogeneous and that this heterogeneity has implications for histopathological diagnosis. KEY POINTS: • Lung cancer is heterogeneous regarding functional and metabolic imaging. • Tumor heterogeneity may have implications in histopathological diagnosis. • Intralesional lower levels of ADC target highly suspected areas with a significant improvement in lung cancer diagnosis.

Optimization of percutaneous biopsy for diagnosis and pretreatment risk assessment of neuroblastoma.

BACKGROUND: Image-guided percutaneous core needle biopsy (PCNB) is increasingly utilized to diagnose solid tumors. The objective of this study is to determine whether PCNB is adequate for modern biologic characterization of neuroblastoma. PROCEDURE: A multi-institutional retrospective study was performed by the Pediatric Surgical Oncology Research Collaborative on children with neuroblastoma at 12 institutions over a 3-year period. Data collected included demographics, clinical details, biopsy technique, complications, and adequacy of biopsies for cytogenetic markers utilized by the Children's Oncology Group for risk stratification. RESULTS: A total of 243 children were identified with a diagnosis of neuroblastoma: 79 (32.5%) tumor excision at diagnosis, 94 (38.7%) open incisional biopsy (IB), and 70 (28.8%) PCNB. Compared to IB, there was no significant difference in ability to accurately obtain a primary diagnosis by PCNB (95.7% vs 98.9%, P = .314) or determine MYCN copy number (92.4% vs 97.8%, P = .111). The yield for loss of heterozygosity and tumor ploidy was lower with PCNB versus IB (56.1% vs 90.9%, P < .05; and 58.0% vs. 88.5%, P < .05). Complications did not differ between groups (2.9 % vs 3.3%, P = 1.000), though the PCNB group had fewer blood transfusions and lower opioid usage. Efficacy of PCNB was improved for loss of heterozygosity when a pediatric pathologist evaluated the fresh specimen for adequacy. CONCLUSIONS: PCNB is a less invasive alternative to open biopsy for primary diagnosis and MYCN oncogene status in patients with neuroblastoma. Our data suggest that PCNB could be optimized for complete genetic analysis by standardized protocols and real-time pathology assessment of specimen quality.

Short-term complications for percutaneous ultrasound-guided biopsy of renal masses in adult outpatients.

Background Ultrasound-guided percutaneous kidney tumor biopsy (UGPKB) plays an important role in the diagnosis of renal tumor but there are no consensuses with respect to the length and the extend of the post-biopsy observation period. Purpose To assess the short-term complication rate after UGPKB and to evaluate whether the onset of complications allows for the procedure to be performed in an outpatient setting with same-day discharge. Material and Methods Between March 2012 and March 2014, a total of 287 UGPKB were performed in an outpatient setting at a Danish university referral center. All patient records were retrospectively reviewed and post-biopsy complications as well as biochemical parameters were registered. Results The overall complication rate was 3.8% (11 patients). Major complications occurred in 1.0% of all cases (three patients); one patient with ongoing bleeding that required intervention and two patients with septicemia. Minor complications occurred in 2.8% of cases (eight patients); six patients with self-limiting gross hematuria, one patient with small asymptomatic subcapsular hematoma, and one patient with vasovagal syncope. The timing of both minor and major complication onset ranged from the time of biopsy and up to four days after discharge. Conclusion UGPKB of indeterminate renal masses in adult patients in an outpatient setting appears to be a safe procedure with a very low rate of major complications. Same-day discharge after renal mass biopsy seems feasible.

CT-guided percutaneous biopsy of sclerotic bone lesions: diagnostic outcomes.

OBJECTIVE: To determine the diagnostic yield of CT-guided percutaneous biopsy of densely sclerotic bone lesions. MATERIALS AND METHODS: We retrospectively analyzed CT-guided percutaneous bone biopsies performed at our institution from September 2008 through August 2011 (329 cases) and from September 2012 through August 2015 (324 cases) after adoption of a battery-powered drill system (OnControl). Bone lesions were included in the analysis if they were >70% sclerotic by visual inspection, had a density > 2 times that of adjacent trabecular bone, and had an attenuation of ≥250 HU. Pathological fractures, diskitis-osteomyelitis, and osteoid osteomas were excluded. Eligible cases were characterized by lesion location, maximum lesion diameter, mean density, biopsy needle type and gauge, reported complications, and histological diagnosis. Clinical and imaging follow-up was used to confirm histological diagnosis. Cases in which a benign histological diagnosis could not be confirmed by imaging over a minimum period of 1 year were excluded. RESULTS: A total of 37 biopsies of sclerotic bone lesions met the inclusion criteria, 17 of which were performed with a power drill needle and 20 of which were performed with a manually driven needle. The mean lesion density was 604.1 HU. The overall diagnostic yield was 78.4%; overall diagnostic accuracy was 94.6%, and the false-negative rate was 5.4%. Diagnostic yield and accuracy were 82.4% and 100% respectively, with a power drill and 75% and 90% respectively, with a manual device. Diagnostic yield for lesions ≥700 HU was 90% (9 out of 10). CONCLUSION: Densely sclerotic bone lesions are amenable to percutaneous needle biopsy.

Comparison of biliary brush biopsy and fine needle biopsy in the diagnosis of biliary strictures.

PURPOSE: The purpose of this study is to evaluate the accuracy of percutaneous fine needle biopsy (FNB) and brush biopsy (BB) at a cancer center. MATERIAL AND METHODS: Retrospective analysis of all bile duct biopsies performed in Interventional Radiology between January 2000 and January 2015 was performed. FNB was performed under real-time cholangiographic guidance using a notched needle directed at the bile duct stricture. BB was performed by advancing a brush across the stricture and moving it back and forth to scrape the stricture. Biopsy results were categorized as true positive (TP), true negative (TN), false positive (FP) and false negative (FN) based on pathology reports and confirmed by surgical specimens or clinical follow-up of at least six months. Fisher's exact test was used to compare the rate of TP in FNB and BB. RESULTS: One-hundred and nineteen patients underwent FNB or BB. Fifteen were censored because of lack of follow-up. The remaining 104 patients underwent a total of 117 bile duct biopsies during the study period: 34 FNB and 83 BB. There were no complications in either group. In the FNB group 22/34 (64%) biopsies were TP, 4/34(12%) were TN and there were 8(24%) FN biopsies. In the BB group, 20/83 (24%) were TP, 38/83 (46%) TN and 25/83 (30%) FN biopsies. There were no FP biopsies in either group. The sensitivity of detecting malignancy by FNB was significantly higher than that by BB (73% vs 44%, p < .0005). There were no complications associated with FNB or BB. CONCLUSIONS: FNB of bile duct strictures is safe and has a higher sensitivity for detecting malignancy than BB.

"Scout No Scan" Technique Reduces Patient Radiation Exposure During CT-Guided Spine Biopsy.

OBJECTIVE: The objective of this article is to report our experience with a technique for CT-guided spine biopsies that we refer to as the "scout no scan" technique. CONCLUSION: The scout no scan technique can significantly lower radiation exposure while maintaining high diagnostic yields for CT-guided spinal biopsies.

CT-Guided Biopsy of Entirely Endophytic Small Renal Masses: Diagnostic Rates and Complications Using Standard-Dose and Reduced-Dose CT Protocols.

OBJECTIVE: The objective of this study was to compare diagnostic rates and complications using standard-dose and reduced-dose CT protocols for CT-guided biopsies of entirely endophytic small renal masses. MATERIALS AND METHODS: A total of 73 patients with 74 tumors underwent CT-guided biopsy of entirely endophytic small renal masses (≤ 4 cm). Diagnostic rates, histologic findings, radiation doses, complication rates, and procedure duration were assessed by retrospective review of charts and images and were compared for the standard-dose and reduced-dose groups. RESULTS: Biopsy was performed using the standard-dose CT protocol (mean reference tube current-exposure time setting, 205.0 ± 19.0 [SD] mAs) for 43 lesions, and the reduced-dose CT protocol (reference tube current-exposure time setting, 42.0 ± 7.5 mAs) for 31 lesions. In the reduced-dose group, there were 29 lesions (94%) with diagnostic results. In the standard-dose group, biopsies of 42 lesions (98%) yielded diagnostic results. No complications that needed intervention or hospitalization occurred in either group. The dose-length product (DLP) was significantly higher in the standard-dose group than the reduced-dose group (574 ± 232 vs 152 ± 63 mGy × cm, respectively; p < 0.05). The mean procedure duration did not differ significantly for the two groups. CONCLUSION: Biopsy of entirely endophytic small renal masses that is performed with guidance using a reduced-dose CT protocol gives diagnostic results similar to a standard-dose CT protocol without any increase in complication rate or procedure duration.

Pediatric renal transplant biopsy with ultrasound guidance: the 'core' essentials.

This review provides a comprehensive and practical approach to pediatric percutaneous renal transplant biopsies, highlighting techniques and strategies to optimize adequate sample yield and ensure patient safety. In children with end-stage renal disease, transplantation is the preferred choice of therapy, providing for overall lower long-term morbidity and mortality compared with dialysis. In the ongoing management of renal transplant patients, core tissue sampling via a percutaneous renal biopsy remains the gold standard when transplant dysfunction is suspected. Indications for renal transplant biopsy and techniques/tools for adequate sample yield are discussed. Strategies for common challenges such as poor visualization and renal transplant mobility are addressed. We discuss the clinical signs, techniques and imaging findings for common complications including hematomas, arteriovenous fistulas and pseudoaneurysms. Although the percutaneous renal transplant biopsy procedure is generally safe with rare complications, care must be taken to ensure major complications are promptly recognized and treated. Adequate tissue samples obtained via renal biopsy are imperative to promptly identify transplant rejection to provide valuable information for patient diagnosis, treatment and outcomes. Radiologist and nephrologist attention to proper ultrasound techniques and optimal biopsy tools are critical to ensure tissue adequacy and minimize complications.

Value of percutaneous needle biopsy of small renal tumors in patients referred for cryoablation.

PURPOSE: To retrospectively evaluate the safety and diagnostic yield of needle biopsy of small renal tumors, and the clinical consequences of performing needle biopsy in patients referred for percutaneous cryoablation before their treatment. MATERIAL AND METHODS: Biopsy was performed for 120 tumors (mean diameter, 2.2 cm) in 119 patients. All procedures were divided into diagnostic and non-diagnostic biopsies. Various variables were compared between the two groups. All cryoablation procedures were divided into two groups: procedures with or without simultaneous biopsy. The rates of benign or non-diagnostic tumors in each group were compared. RESULTS: After performing 120 initial and eight repeat biopsies, Grade 1 bleedings occurred in 44 cases. Six tumors were non-diagnostic and 114 were pathologically diagnosed. There were no significant variables between the diagnostic and non-diagnostic biopsies. Unnecessary cryoablation was avoided in nine benign lesions by performing biopsy in advance. Cryoablation performed simultaneously with biopsy included significantly more benign or non-diagnostic tumors than cryoablation performed after biopsy (15.2% vs. 1.4%; p = .01). CONCLUSIONS: Percutaneous biopsy of small renal tumors referred for cryoablation was a safe procedure with high diagnostic yield. The confirmation of pathological diagnosis prior to cryoablation is necessary because patients with benign tumors can avoid unnecessary treatment.

Radial scars without atypia in percutaneous biopsy specimens: can they obviate surgical biopsy? / Cicatriz radial sin atipia en biopsia percutánea. ¿Puede evitarse la biopsia quirúrgica?

OBJECTIVE: To evaluate the need for surgical biopsy in patients diagnosed with radial scars without atypia by percutaneous biopsy. MATERIAL AND METHODS: In this retrospective observational study, we selected patients with a histological diagnosis of radial scar in specimens obtained by percutaneous biopsy during an 8-year period. The statistical analysis was centered on patients with radial scar without atypia (we assessed the radiologic presentation, the results of the percutaneous biopsy, and their correlation with the results of surgical biopsy and follow-up) and we added the patients with atypia and cancer in the elaboration of the diagnostic indices. RESULTS: We identified 96 patients with radial scar on percutaneous biopsy; 54 had no atypia, 18 had atypia, and 24 had cancer. Among patients with radial scar without atypia, there were no statistically significant differences between patients who underwent imaging follow-up and those who underwent surgical biopsy (p>0.05). The rate of underdiagnosis for percutaneous biopsy in patients without atypia was 1.9%. The rates of diagnosis obtained with percutaneous biopsy in relation to follow-up and surgical biopsy in the 96 cases were sensitivity 92.3%, specificity 100%, positive predictive value 100%, negative predictive value 97.2%, and accuracy 97.9%. The area under the ROC curve was 0.96 (p<0.001), and the kappa concordance index was 0.95 (p<0.001) CONCLUSIONS: We consider that it is not necessary to perform surgical biopsies in patients with radial scars without atypia on percutaneous biopsies because the rate of underestimation is very low and the concordance between the diagnosis reached by percutaneous biopsy and the definitive diagnosis is very high.

Active surveillance is suitable for intermediate term follow-up of renal oncocytoma diagnosed by percutaneous core biopsy.

OBJECTIVES: To evaluate the intermediate outcome of conservative management in patients with biopsy-proven oncocytoma. PATIENTS AND METHODS: Patients with oncocytoma diagnosed on percutaneous core biopsy between January 2000 to December 2014 were identified from the renal biopsy database of a large specialist urologic pathology laboratory. After review of patient clinical records, the study cohort comprised only of patients enrolled in active surveillance. Clinicopathological and follow-up details were reviewed for each case, in particular: type and interval of surveillance imaging, tumour growth, definitive intervention and reason for intervention. Where possible, correlation was made between the final surgical and the initial biopsy specimens. RESULTS: Fifty three patients diagnosed with oncocytoma on core biopsy were initially placed on active surveillance with median follow-up of 34 months (range 6-109). The median age at diagnosis was 65 years (range 20-85) and median tumour size was 30 mm (range 13-87). Mean average tumour growth was 1.4 mm per annum (median 0 mm/year) with the majority (36 of 53, 68%) exhibiting minimal growth (less than 2 mm per annum) or partial regression. Forty seven of the 53 patients remained on active surveillance with no significant progression. Six patients elected to undergo definitive intervention (five surgical excision, one ablation). Renal oncocytoma was confirmed in all five patients who underwent surgical excision of their lesions. CONCLUSIONS: The majority of oncocytomas in this study showed minimal growth rate or regression. Patients with biopsy proven oncocytoma can be conservatively managed with active surveillance.