Increasing the number of biopsy cores before renal cryoablation increases the diagnostic yield

Efficacy of percutaneous cryoablation of renal cell carcinoma in older patients with medical comorbidities: Outcome study in 70 patients

INTRODUCTION

The aim of this study was to establish the efficacy of cryoablation for incidentally discovered small renal cell carcinomas in older patients with medical comorbidities.

METHODS

We carried out a retrospective chart analysis of outcomes of 70 patients treated by cryoablation. The inclusion criteria were age >56 years, medical comorbidities (Charlson class I-III), and suitability for cryoablation established by urologists and interventional radiologists. In total, 43 patients were male, 27 female, and the age range was 56 to 89. The lesions measured 1.5 to 4 cm; 29 were high-grade Fuhrman and 41 were low grade. All lesions were treated by 2 10-minute freezing cycles separated by an 8-minute thawing period. One to seven cryoprobes were inserted according to a preoperative, 3D computed tomography (CT)-based plan.

RESULTS

Results were assessed on follow-up CTs (at 8-9 months). Of the 70 patients, 68 were treated by cryoablations and surgical salvage procedures; these patients were free of disease for 23 to 72 months (mean 39). One patient experienced recurrence and the other was lost to follow-up. One or two cryoablations rendered 66 patients tumour-free and additional surgery rendered another 2 patients tumour-free. The location and configuration of the lesion affected outcomes. Of the 27 posterior lesions, there was 1 failure; of the postero-lateral lesions, there were 4 failures; of the anterior lesions, there were 5 lesions; finally of the 32 central or deep seated lesions, there were 9 failures. Implants with one and two cryoprobes had a high recurrence rate. Three major complications were managed by minor interventions. The mean hospitalization was 1.3 days and the procedure times were variable.

CONCLUSION

Percutaneous cryoablation is recommended as a minimally invasive nephron-sparing treatment for amenable lesions in older patients with medical comorbidities.

Histopathologic findings of small renal tumor biopsies performed immediately after cryoablation therapy: a retrospective study of 50 cases

OBJECTIVES

To evaluate the histopathology of small renal tumor biopsies following cryoablation.

METHODS

We retrospectively evaluated small renal tumor biopsy specimens after cryoablation treatment for renal cell carcinoma and determined the ability to differentiate tumor types, effect on nuclear grading, immunohistochemical staining, and if the number of freeze cycles affected interpretation.

RESULTS

Of the biopsy specimens, 66% were diagnostic of tumor and 34% showed normal renal parenchyma. Tumor subtype was determined in 91% of diagnostic cases. Nuclear grading was affected due to freeze effect, complicating the assessment of chromatin pattern and nucleolar details at low magnification. In particular, the distinction between Fuhrman nuclear grades I and II was compromised; these were designated as low nuclear grade. Immunohistochemical staining was retained similar to untreated tumors. Tumor subtyping was not affected after one or two freeze cycles.

CONCLUSIONS

Biopsies performed immediately after cryoablation can be used to render an optimal histologic diagnosis.

The role of pathology in small renal mass laparoscopic cryoablation

Objective. We evaluated histological outcome of intraoperative biopsies at laparoscopic renal mass cryoablation (LCA), prevalence of peritumoral fat tissue invasion, and risk of tract seeding. Methods. Patients were biopsied 3–5 times (16-gauge). Histology was analyzed by general pathologists and reviewed. Peritumoral fat was histologically examined. The trocar used for biopsy-guidance was examined by cytology. Records were studied for reporting tract metastasis. Results. 77 biopsied renal masses with mean ± SD diameter 30 ± 7.4 mm were histologically classified by primary and review pathology revealing 64 and 62 malignancies, 13 and 15 benign lesions, respectively. In 30/34, the fat covered a carcinoma but revealed no malignancy. Cytology showed no malignant cells but was inconclusive in 1 case. No tract metastasis occurred. Conclusions. The use of an intraoperative biopsy protocol provides histological diagnosis of all renal masses. No existence of peritumoral fat tissue invasion or tract seeding was found.

Contrast enhanced ultrasound of renal masses

Contrast enhanced ultrasound (CEUS) has gained clinical importance over the last years for the characterization of hepatic masses. Its role in extrahepatic indications has been investigated repeatedly but has been less comprehensively studied. Currently more than 50% of renal masses are incidentally diagnosed, mostly by B-mode ultrasound. The method of choice for characterization of renal lesions is contrast enhanced computed tomography (CECT). In the case of cystic lesions CECT refers to the Bosniak classification for cystic lesions to assess the risk of malignant behavior. The majority of masses are renal cell carcinoma, but the exact proportion is controversial. Disadvantages of CECT are a significant risk for patients with impaired renal function, allergic reactions and hyperthyroidism due to iodinated contrast agents. Several studies concerning CEUS for the characterization of both solid and cystic renal lesions have been published, but prospective multicenter studies are missing, the presented data being mainly descriptive. The aim of the this manuscript is to review the current literature for CEUS in renal masses, to summarize the available data and focus on possible concepts for studies in the future.