Reliability and Management Outcomes Following a Percutaneous Biopsy Diagnosis of Oncocytoma: A 15-year Retrospective Analysis.

Background There is uncertainty in the management of renal masses diagnosed as oncocytomas with image-guided percutaneous biopsy. Purpose To assess the reliability of a diagnosis of oncocytoma based on image-guided percutaneous renal mass biopsy and evaluate patient outcomes following different management strategies. Materials and Methods In this retrospective study, image-guided percutaneous biopsy pathology reports from April 2004 to April 2019 were searched for keywords "oncocytoma" and "oncocytic neoplasm" and compared with surgical pathology or repeat biopsy results. Patients with at least 12 months of clinical follow-up and known cause of death were grouped according to management strategies, and disease-specific survival and metastatic renal cell carcinoma (RCC)-free survival were compared. Mass growth rates were calculated with use of a normal linear mixed model. Results The database yielded 160 biopsy reports of 149 renal masses in 139 patients; 149 masses were categorized as oncocytoma (n = 107), likely oncocytoma (n = 12), oncocytic neoplasm (n = 28), and indeterminate with oncocytoma in differential (n = 2). Biopsied masses categorized as oncocytoma or likely oncocytoma were oncocytomas in 16 of 17 masses (94%) based on surgical pathology or repeat biopsy; four of eight masses (50%) categorized as oncocytic neoplasms were low-grade RCCs. Outcome analysis included 121 patients (mean age ± SD, 68 years ± 9.1; 82 men); 80 patients initially underwent active surveillance (11 were later treated), 33 underwent ablation, and eight underwent surgery. Disease-specific survival and metastatic-free survival were 100% after each management strategy (median follow-up, 86.6 months; range, 14.2-207.9 months). Mass growth rate (mean, 1.7 mm per year) showed no evidence of a significant difference among biopsy result categories (P = .37) or initial (P = .84) or final management strategies (P = .11). Conclusion Image-guided percutaneous biopsy diagnosis of renal oncocytoma was reliable. Although some masses diagnosed as oncocytic neoplasms were low-grade renal cell carcinomas (RCCs) at final diagnosis, no patients died of RCC, including those managed with active surveillance. © RSNA, 2023 See also the editorial by Lockhart in this issue.

Feasibility and safety of bipolar radiofrequency track cautery during percutaneous image-guided abdominal biopsy procedures.

PURPOSE: The purpose of this study was to assess the feasibility and safety of using a bipolar radiofrequency track cautery device during percutaneous image-guided abdominal biopsy procedures in at-risk patients. METHODS: Forty-two patients (26-79 years old; female 44%) with at least one bleeding risk factor who underwent an abdominal image-guided (CT or US) biopsy and intended bipolar radiofrequency track cautery (BRTC) were retrospectively studied. An 18G radiofrequency electrode was inserted through a 17G biopsy introducer needle immediately following coaxial 18G core biopsy, to cauterize the biopsy track using temperature control. Bleeding risk factors, technical success, and adverse events were recorded. RESULTS: BRTC was technically successful in 41/42 (98%) of procedures; in one patient, the introducer needle retracted from the liver due to respiratory motion prior to BRTC. BRTC following percutaneous biopsy was applied during 41 abdominal biopsy procedures (renal mass = 12, renal parenchyma = 10, liver mass = 9, liver parenchyma = 5, splenic mass or parenchyma = 4, gastrohepatic mass = 1). All patients had one or more of the following risk factors: high-risk organ (spleen or renal parenchyma), hypervascular mass, elevated prothrombin time, renal insufficiency, thrombocytopenia, recent anticoagulation or anticoagulation not withheld for recommended interval, cirrhosis, intraprocedural hypertension, brisk back bleeding observed from the introducer needle, or subcapsular tumor location. No severe adverse events (grade 3 or higher) occurred. Two (2/41, 5%) mild (grade 1) bleeding events did not cause symptoms or require intervention. CONCLUSION: Bipolar radiofrequency track cautery was feasible and safe during percutaneous image-guided abdominal biopsy procedures. IRB approval: MBG 2022P002277.

Anastomosing hemangiomas: locations of occurrence, imaging features, and diagnosis with percutaneous biopsy.

PURPOSE: To describe a series of anastomosing hemangiomas and report its locations, imaging features, and the use of image-guided percutaneous biopsy to establish the diagnosis. METHODS: In this institutional review board-approved, HIPAA compliant, retrospective study, an electronic pathology database was searched for all cases of anastomosing hemangioma from January 2009 to January 2015, yielding 32 cases (18 men, mean age 62 years). Tumor locations were recorded, and in a subgroup of patients with imaging, image characteristics (contour, attenuation, enhancement after intravenous contrast injection, the presence of hemorrhage or fat attenuation, and non-enhancing component) were evaluated. The number of cases diagnosed using percutaneous biopsy specimen was determined, and in a subgroup of these patients, biopsy technique and complications were assessed. RESULTS: Anastomosing hemangioma occurred in different locations, more commonly in the retroperitoneum (15/32, 47%), including the kidney (7/32, 22%), and more rarely in the ovary (4/32, 13%) and liver (2/32, 6%). Of the 5 cases with imaging available, four anastomosing hemangiomas were in the retroperitoneum (one in retroperitoneal fat, one para-aortic, one renal and one adrenal) and the fifth was mesenteric. Most tumors were well circumscribed (4/5, 80%), and on non-contrast CT, they appeared as mildly hyperdense (4/5, 80%) with avid contrast enhancement and heterogeneous attenuation (4/5, 80%) due to the presence of fat (2/5, 40%) or non-enhancing components (2/5, 40%). Diagnosis was rendered solely based on percutaneous biopsy in 7/32 (22%), all of which were core biopsy specimens. Fine-needle aspiration biopsy was performed in 1 case, which was non-diagnostic. CONCLUSIONS: Anastomosing hemangioma, a rare benign vascular tumor, is most commonly seen in the retroperitoneal fat and kidneys. On imaging, they are usually circumscribed, hyperdense, and heterogeneous due to fatty or non-enhancing hypodense areas and show avid post-contrast enhancement. Percutaneous biopsy can yield the diagnosis, potentially avoiding surgery.