Needle tract seeding of transitional cell carcinoma following fine-needle aspiration of a renal mass

Imaging in Upper Tract Urothelial Carcinoma: A Review

Medical imaging is a critical tool in the detection, staging, and treatment planning of upper urinary tract urothelial carcinoma (UTUC). This article reviews the strengths and weaknesses of the different imaging techniques and modalities available clinically. This includes multidetector computed tomography (CT), multiparametric magnetic resonance imaging (MRI), ultrasound (US), and positron emission tomography (PET) for the detection, staging, and management of UTUC. In addition, we review the imaging techniques that are being developed and are on the horizon but have not yet made it to clinical practice. Firstly, we review the imaging findings of primary UTUC and the techniques across multiple modalities. We then discuss imaging findings of metastatic disease. Lastly, we describe the role of imaging in the surveillance after resection of primary UTUC based upon current guidelines.

Feline abdominal ultrasonography: What's normal? What's abnormal? Renal pelvis, ureters and urinary bladder

PRACTICAL RELEVANCE

Abdominal ultrasound plays a vital role in the diagnostic work-up of many cats presenting to general and specialist practitioners. Ultrasound examination of the urinary tract provides important information useful in the investigation of several conditions including ureteral obstruction and cystitis.

CLINICAL CHALLENGES

Despite ultrasonography being a commonly used modality, many practitioners are not comfortable performing an ultrasound examination or interpreting the resulting images. Even for the experienced ultrasonographer, differentiating between incidental findings, such as lipid droplets in the bladder, and pathological changes can be challenging.

AIM

This review, part of an occasional series on feline abdominal ultrasonography, discusses the ultrasonographic examination of the normal and diseased renal pelvis, ureters and urinary bladder. Aimed at general practitioners who wish to improve their knowledge of and confidence in feline abdominal ultrasound, this review is accompanied by high-resolution images and videos available online as supplementary material. Ultrasound examination of the kidneys and perinephric space was discussed in an article published in May 2020.

EQUIPMENT

Ultrasound facilities are readily available to most practitioners, although the use of ultrasonography as a diagnostic tool is highly dependent on operator experience.

EVIDENCE BASE

Information provided in this article is drawn from the published literature and the author's own clinical experience.

Percutaneous Image-guided Core Needle Biopsy for Upper Tract Urothelial Carcinoma

OBJECTIVE

To better understand the safety and diagnostic yield of percutaneous core-needle biopsy (PCNB) for upper tract urothelial carcinoma (UTUC).

METHODS

Of 444 patients undergoing radical nephroureterectomy (RNU) for UTUC between 2009 and 2017 at our institution, 42 who had PCNB prior to RNU were identified for analysis. Endpoints included safety, diagnostic yield, and concordance with RNU pathology. PCNB specimens were deemed histologically concordant with RNU specimens for cases when cytologic evaluation of biopsy specimen and corresponding pathologic evaluation of RNU specimen both made a histologic diagnosis of urothelial carcinoma.

RESULTS

Median tumor size was 3.8 cm (1.2-10.2 cm). All lesions arose from the pelvicalyceal system. CT-guidance was utilized in 52% (n = 22), and ultrasound-guidance in 48% (n = 20). Relative to RNU pathology, 95% of PCNBs demonstrated histologic concordance. Histologic grade was provided in 69% (n = 29) of PCNBs, with a 90% (n = 26) concordance with surgical pathology. Grades 1-2 and 3 complications occurred in 14.3% (n = 6) and 2.4% (n = 1), respectively. At a median follow-up of 28.2 months (range, 1.2-97.1 months) after biopsy, no cases of radiographic tract seeding were identified.

CONCLUSION

In our cohort of 42 patients undergoing RNU for UTUC, PCNB appeared a safe diagnostic tool with high histologic yield and grade concordance. With greater than 2 years of follow-up, no cases of tract seeding were identified.

[CLINICAL CONSIDERATION OF PERCUTANEOUS RENAL BIOPSY FOR ADVANCED RENAL TUMOR]

(Objective) Advanced renal tumors are often difficult to diagnose based on radiological findings. The preset study aimed to evaluate the diagnostic efficacy and safety of percutaneous renal tumor biopsy in patients with advanced renal tumors. (Methods) Thirteen patients (6 males and 7 females) with advanced renal tumors who underwent percutaneous renal tumor biopsy between January 2015 and May 2017 were reviewed retrospectively. (Results) The median patients age was 69 years (range=40-81 years). The median renal tumor size was 91 mm (53-195 mm). Four cases were diagnosed as clear cell renal cell carcinoma (CCRCC), 8 as non-CCRCC, and 1 as malignant lymphoma prior to biopsy. Histopathological diagnoses after biopsy were CCRCC in 3, urothelial carcinoma in 3, and papillary renal cell carcinoma in 2 cases; there was 1 case each of chromophobe renal cell carcinoma, spindle cell RCC, carcinoma of the collecting ducts of Bellini, and nephroblastoma. Diagnosis could not be made in 1 case due to sampling error. Adverse events developed after renal tumor biopsy, with microscopic hematuria in 2 and pyrexia in 1 case. These were Grade 1 events according to the Clavien-Dindo Classification. Disseminated tumors were not observed during the follow-up period. (Conclusion) Percutaneous tumor biopsy for patients with advanced renal tumor is a safe procedure and useful for confirming the diagnosis pathologically before starting medication.

Percutaneous renal tumour biopsy

The use of percutaneous renal tumour biopsy (RTB) as a diagnostic tool for the histological characterization of renal masses has increased dramatically within the last 30 years. This increased utilization has paralleled advances in imaging techniques and an evolving knowledge of the clinical value of nephron sparing surgery. Improved biopsy techniques using image guidance, coupled with the use of smaller gauge needles has led to a decrease in complication rates. Reports from series containing a large number of cases have shown the non-diagnostic rate of RTB to range from 4% to 21%. Re-biopsy has been shown to reduce this rate, while the use of molecular markers further improves diagnostic sensitivity. In parallel with refinements of the biopsy procedure, there has been a rapid expansion in our understanding of the complexity of renal cell neoplasia. The 2013 Vancouver Classification is the current classification for renal tumours, and contains five additional entities recognized as novel forms of renal malignancy. The diagnosis of tumour morphotype on RTB is usually achievable on routine histology; however, immunohistochemical studies may be of assistance in difficult cases. The morphology of the main tumour subtypes, based upon the Vancouver Classification, is described and differentiating features are discussed.

The diagnostic accuracy of percutaneous renal needle core biopsy and its potential impact on the clinical management of renal cortical neoplasms

CONTEXT

While biopsies are now increasingly being performed for the diagnosis of renal cortical neoplasms, the influence of the rendered pathological diagnoses on the clinical management is only rarely documented.

OBJECTIVES

To report our experience with consecutively performed renal biopsies and the potential impact of the diagnosis on subsequent clinical management.

DESIGN

Material from needle biopsies performed consecutively at our institution between 2006 and 2011 was reviewed. The influence of the reported pathology results on the clinical management was determined from patient follow-up medical record review.

RESULTS

In total, 218 percutaneous biopsies for renal masses were performed during this period. Among them, 181 (83%) yielded neoplastic tissue, including 81 clear cell renal cell carcinomas, 29 low-grade oncocytic neoplasms, 7 papillary renal cell carcinomas, 5 clear cell papillary renal cell carcinomas, 5 angiomyolipomas, and 14 urothelial carcinomas. Fourteen additional cases (6%) contained lesional material from clinically known nonneoplastic processes, for a total diagnostic yield of 89%. Twenty-three (11%) were nonrepresentative of lesional tissue. In 10 of these, repeat biopsies or resections established the diagnosis of renal tumors. Biopsy diagnosis was confirmed in 29 of 30 cases (97%) on subsequent nephrectomy. Following the biopsy diagnosis, there were significant differences in the clinical management; overall, 79% of clear cell renal cell carcinomas received therapeutic interventions, and 17% were put on active surveillance. In contrast, 77% of the benign or low-grade lesions were put on active surveillance.

CONCLUSIONS

Accurate and specific diagnosis can be rendered on renal core biopsy in most renal tumors, and the biopsy diagnosis can have a definitive role in their clinical management.

Imaging findings of common benign renal tumors in the era of small renal masses: differential diagnosis from small renal cell carcinoma: current status and future perspectives

The prevalence of small renal masses (SRM) has risen, paralleling the increased usage of cross-sectional imaging. A large proportion of these SRMs are not malignant, and do not require invasive treatment such as nephrectomy. Therefore, differentation between early renal cell carcinoma (RCC) and benign SRM is critical to achieve proper management. This article reviews the radiological features of benign SRMs, with focus on two of the most common benign entities, angiomyolipoma and oncocytoma, in terms of their common imaging findings and differential features from RCC. Furthermore, the role of percutaneous biopsy is discussed as imaging is yet imperfect, therefore necessitating biopsy in certain circumstances to confirm the benignity of SRMs.

Renal Cell Carcinoma Metastasis from Biopsy Associated Hematoma Disruption during Robotic Partial Nephrectomy

We describe a case in which a patient with a past medical history of ovarian cancer received a diagnostic renal biopsy for an incidentally discovered renal mass. During left robotic partial nephrectomy (RPN), a perinephric hematoma was encountered. The hematoma was not present on preoperative imaging and was likely a result of the renal biopsy. The renal cell carcinoma (RCC) and the associated hematoma were widely excised with negative surgical margins. On follow-up imaging at five months postoperatively, a recurrent renal mass at the surgical resection bed and several new nodules in the omentum were detected. During completion left robotic total nephrectomy and omental excision, intraoperative frozen sections confirmed metastatic RCC. We believe that a hematoma seeded with RCC formed as a result of the renal biopsy, and subsequent disruption of the hematoma during RPN caused contamination of RCC into the surrounding structures.

Renal biopsy with 16G needle: a safety study

INTRODUCTION AND OBJECTIVE

The development of percutaneous renal biopsy as a routinary diagnostic procedure for renal masses is topic of discussion for the last few years. However, this technique has been associated with some complications, although infrequent, and morbidity. Our objective is to carry out a descriptive study about complications and outcomes of orthotopic kidney biopsies with 16 G needle.

MATERIAL AND METHODS

A retrospective review of 180 orthotopic ultrasound-guided renal biopsies performed in our service among January 2008 to May 2010 was carried out. The procedure was developed using an automated biopsy gun (16G needle). Multiple clinical variables, early post-procedure complications and its management were collected. Complication rates as well as the relationship between risk factors and occurrence of complications were studied.

RESULTS

Mean age was 55.8 years. The average number of biopsy cylinders per intervention was 2.49. The overall complication rate was 5.6%. An interventionist attitude derived from complication of the procedure was necessary in only 3 patients (1.67%). No surgical interventions were required and no death as consequence of procedure was registered. No relationship between hypertension (P=.09) previous anticoagulation (P=.099) or previous antiaggregation (P=.603) and complications were demonstrated. In 2.8% of biopsies the material obtained was insufficient for diagnosing.

CONCLUSIONS

Percutaneous ultrasound-guided renal biopsy with 16G needle is a safe technique with high diagnostic performance.

Solid renal masses: what the numbers tell us

OBJECTIVE

Solid renal masses are most often incidentally detected at imaging as small (≤ 4 cm) localized lesions. These lesions comprise a wide spectrum of benign and malignant histologic subtypes, but are largely treated with surgical resection given the limited ability of imaging to differentiate among them with consistency and high accuracy. Numerous studies have thus examined the ability of CT and MRI techniques to separate benign lesions from malignancies and to predict renal cancer histologic grade and subtype. This article synthesizes the evidence regarding renal mass characterization at CT and MRI, provides diagnostic algorithms for evidence-based practice, and highlights areas of further research needed to drive imaging-based management of renal masses.

CONCLUSION

Despite extensive study of morphologic and quantitative criteria at conventional imaging, no CT or MRI techniques can reliably distinguish solid benign tumors, such as oncocytoma and lipid-poor angiomyolipoma, from malignant renal tumors. Larger studies are required to validate recently developed techniques, such as diffusion-weighted imaging. Evidence-based practice includes MRI to assess renal lesions in situations where CT is limited and to help guide management in patients who are considered borderline surgical candidates.

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%).

Successful percutaneous radiologic management of renal cell carcinoma tumor seeding caused by percutaneous biopsy performed before ablation

A case is reported of the successful image-based detection, diagnosis, and percutaneous ablation of tumor seeding in a 61-year-old man that was caused by percutaneous biopsy of a renal cell carcinoma performed before cryoablation and was not detected until 4 years after the biopsy procedure. Although tumor seeding is a rare complication after percutaneous biopsy or ablation, this case emphasizes the importance of imaging surveillance of the needle tract used during both biopsy and ablation procedures, provides guidance on measures that can be used to minimize the occurrence of tumor seeding, and demonstrates that entirely radiologic management can be successful.

Imaging of primary and secondary renal lymphoma

OBJECTIVE

This article reviews the CT and MRI patterns of primary and secondary renal lymphomas and discusses the role of percutaneous biopsy in diagnosis and management.

CONCLUSION

Renal lymphoma has a variable imaging spectrum and may mimic renal cell carcinoma. An awareness of the typical and atypical imaging features of both primary and secondary renal lymphomas can help the radiologist to suggest these diagnoses and recommend biopsy when appropriate.

Renal cell carcinoma seeding of a percutaneous biopsy tract

We report the case of a 68-year-old male with extension of papillary renal cell carcinoma (Fuhrman grade III) along a percutanous biopsy tract detected at the time of partial nephrectomy. Biopsy was performed to a obtain tissue diagnosis of a complex renal cyst as the patient was unable to receive intravenous contrast for imaging due to a severe allergy. Although biopsy of indeterminate renal lesions can provide valuable diagnostic information, there are inherent risks associated with this procedure. The rare occurrence of tumour seeding should be considered when recommending percutaneous biopsy to a patient with a renal mass.

Factors influencing the opinion of individuals in determining tumour spread after biopsy

Background

People often have concerns regarding tumour spread after biopsy which leads to a delay in seeking expert medical advice. The data regarding this perception is scanty. Therefore, we conducted this cross sectional study to explore the beliefs and perceptions of individuals regarding tumour spread after biopsy and the basis of those beliefs.

Methods

The survey was conducted in outpatient areas of two different tertiary care hospitals of Karachi namely Aga Khan University Hospital Karachi (AKUH) and Karachi Institute of Radiotherapy and Nuclear Medicine (KIRAN). We interviewed 600 individuals and documented their responses on a questionnaire. There were 400 responders from Aga Khan's Consulting Clinic and 100 each from Aga Khan's Oncology Clinic and KIRAN.

Results

Only 50% of the respondents chose biopsy as the best test for diagnosis of cancer. The level of education was statistically significant in making this choice of answer (p = 0.02) only in univariate analysis. Those individuals who were involved in the work up of cancer patients irrespective of their educational status gave more intelligent answers (p = 0.003). The tumour disturbance after biopsy was regarded as a major factor among 127 respondents (53%) who believed that biopsy could lead to spread of tumour.

Conclusions

Our study revealed that awareness regarding cancer diagnosis and biopsy is lacking among general public and it does not co-relate well with the level of formal education. These misconception and taboos need to be addressed in public seminars and in the media in order to increase the awareness which could facilitate prompt diagnosis.

Tumour seeding following percutaneous needle biopsy: the real story!

The demand for percutaneous needle biopsy is greater than ever before and with the majority of procedures requiring imaging guidance, radiologists have an increasingly important role in the diagnostic work-up of patients with suspected malignancy. All invasive procedures incur potential risks; therefore, clinicians should be aware of the most frequently encountered complications and have a realistic idea of their likelihood. Tumour seeding, whereby malignant cells are deposited along the tract of a biopsy needle, can have disastrous consequences particularly in patients who are organ transplant candidates or in those who would otherwise expect good long-term survival. Fortunately, tumour seeding is a rare occurrence, yet the issue invariably receives a high profile and is often regarded as a major contraindication to certain biopsy procedures. Although its existence is in no doubt, realistic insight into its likelihood across the spectrum of biopsy procedures and multiple anatomical sites is required to permit accurate patient counselling and risk stratification. This review provides a comprehensive overview of tumour seeding and examines the likelihood of this much feared complication across the range of commonly performed diagnostic biopsy procedures. Conclusions have been derived from an extensive analysis of the published literature, and a number of key recommendations should assist practitioners in their everyday practice.

Does the taking of biopsies affect the metastatic potential of tumours? A systematic review of reports on veterinary and human cases and animal models

Clinicians and pathologists are sporadically asked by owners whether the taking of tumour biopsies may affect the behaviour of the tumour, including its potential to metastasise. Unfortunately, systematic studies on this subject are unavailable in veterinary medicine, and the aim of this study was to estimate the risk of adverse effects of biopsy taking on tumour progression in animals. A systematic review of veterinary and human case reports and clinical studies as well as experimental animal models of biopsy-induced tumour metastasis was undertaken. There were only two veterinary case reports of needle tract metastases (NTM) following the taking of needle biopsies from urogenital and pulmonary tumours. Seventeen experimental studies found a high incidence of NTM but only a rat osteosarcoma and a hamster squamous carcinoma model showed an increased incidence of distant or regional metastases after incision or excision biopsy. In human medicine, the occurrence of NTM has been reported after the taking of biopsies from mesotheliomas (15%), melanomas (11%) and gall bladder tumours (11%), liver metastases of colon carcinomas (4%) and mammary carcinomas (4%) but an incidence of only <1% for all other tumours. Circulating tumour cells increased immediately after the taking of biopsies from human squamous cell, prostate, breast and hepatocellular carcinomas. Although no increased risk of biopsy-induced distant metastasis has been reported for any type of tumour, this is inconclusive due to a lack of non-biopsied control groups in human studies. Reports of biopsy-induced metastasis in animal tumours indicate that the taking of transcutaneous biopsies from urogenital tumours may be associated with a risk of NTM. However, there is no evidence of a general increase in risk of distant metastases in any tumour type in people or animals. The overall risk therefore appears to be negligible when compared to the valuable information obtained from biopsies in veterinary practice.

A technical note: pre-operative ultrasound-guided wire localization in head and neck surgery

Ultrasound-guided wire localization of impalpable lesions is a well-recognized technique in the management of breast pathology, but its use in the head and neck is not well described. Performed under local anesthesia, high-resolution ultrasound provides real-time imaging for accurate placement of the wire resulting in fewer complications. Wire localization can focus the surgical approach, which reduces operating time and minimizes trauma to surrounding tissues. In this technical note, we describe two cases of pre-operative ultrasound-guided wire localization to facilitate the surgical excision of impalpable neck lesions.

Renal mass biopsy to guide treatment decisions for small incidental renal tumors: a cost-effectiveness analysis

PURPOSE

To evaluate the effectiveness, cost, and cost-effectiveness of using renal mass biopsy to guide treatment decisions for small incidentally detected renal tumors.

MATERIALS AND METHODS

A decision-analytic Markov model was developed to estimate life expectancy and lifetime costs for patients with small (< or = 4-cm) renal tumors. Two strategies were compared: renal mass biopsy to triage patients to surgery or imaging surveillance and empiric nephron-sparing surgery. The model incorporated biopsy performance, the probability of track seeding with malignant cells, the prevalence and growth of benign and malignant tumors, treatment effectiveness and costs, and patient outcomes. An incremental cost-effectiveness analysis was performed to identify strategy preference under a willingness-to-pay threshold of $75,000 per quality-adjusted life-year (QALY). Effects of changes in key parameters on strategy preference were evaluated in sensitivity analysis.

RESULTS

Under base-case assumptions, the biopsy strategy yielded a minimally greater quality-adjusted life expectancy (4 days) than did empiric surgery at a lower lifetime cost ($3466), dominating surgery from a cost-effectiveness perspective. Over the majority of parameter ranges tested in one-way sensitivity analysis, the biopsy strategy dominated surgery or was cost-effective relative to surgery based on a $75,000-per-QALY willingness-to-pay threshold. In two-way sensitivity analysis, surgery yielded greater life expectancy when the prevalence of malignancy and propensity for biopsy-negative cancers to metastasize were both higher than expected or when the sensitivity and specificity of biopsy were both lower than expected.

CONCLUSION

The use of biopsy to guide treatment decisions for small incidentally detected renal tumors is cost-effective and can prevent unnecessary surgery in many cases.

Prospective cytological assessment of gastrointestinal luminal fluid acquired during EUS: a potential source of false-positive FNA and needle tract seeding

OBJECTIVES

Endoscopic ultrasound (EUS) fine needle aspiration (FNA) can result in false-positive cytology and can also cause needle tract seeding. Our goal was to evaluate a potential cause, namely, the presence of malignant cells within gastrointestinal (GI) luminal fluid, either as a result of tumor sloughing from luminal cancers or secondary to FNA of extraluminal sites.

METHODS

During EUS, luminal fluid that is usually aspirated through the echoendoscope suction channel and discarded was instead submitted for cytological analysis among patients with cancer and benign disease. Pre- and post-FNA luminal fluid samples were collected to discern the role of FNA in inducing a positive cytology. When not performing FNA, one sample was collected for the entire examination. The final diagnosis was based on strict clinicopathological criteria and >or=2-year follow-up. This study was conducted in a tertiary referral center.

RESULTS

We assessed the prevalence of luminal fluid-positive cytology among patients with luminal (e.g., esophageal), extraluminal (e.g., pancreatic), and benign disease. Among the 140 patients prospectively enrolled with sufficient sampling and follow-up, an examination of luminal fluid cytology showed positive results for malignancy in luminal and extraluminal cancer patients, 48 and 10%, respectively. This included 8 out of 23 esophageal, 4 of 5 gastric, and 9 of 15 rectal cancers. The positive luminal fluid cytology rate with luminal cancers was not affected by performing FNA. Post-FNA luminal fluid cytology was positive in 3 out of 26 with pancreatic cancers. Cytological examination of luminal fluid aspirates did not demonstrate malignant cells in any patient with nonmalignant disease.

CONCLUSIONS

Malignant cells are commonly present in the GI luminal fluid of patients with luminal cancers and can also be found in patients with pancreatic cancer after EUS FNA. Further study is needed to determine the impact of these findings on cytological interpretation, staging, risk of needle tract seeding, and patient care and outcomes.

Image-Guided Biopsy-Diagnosed Renal Cell Carcinoma: Critical Appraisal of Technique and Long-Term Follow-Up

OBJECTIVES

To critically appraise and determine the impact of image-guided biopsy on the management of indeterminate renal masses. A comparison of long-term follow-up of renal cell carcinoma (RCC) diagnosed by image-guided biopsy and radiologically obvious RCC was also carried out.

PATIENTS AND METHODS

Data were collected for all the consecutive patients requiring renal core biopsies for the diagnosis of indeterminate renal masses between January 1996 and January 2006. The long-term outcome of diagnostic and nondiagnostic renal biopsies was assessed. Furthermore, the long-term outcome of RCC diagnosed following biopsies was compared with nonbiopsy radical nephrectomy done during the same time period.

RESULTS

Of the 70 biopsy procedures performed, 9 were nondiagnostic and 61 were diagnostic on histopathologic examinations (17 benign and 44 malignant). The histopathology of all radical nephrectomies was identical to the pathology of biopsy specimens. Of the nine nondiagnostic cases, one patient had a repeat biopsy that was confirmed as RCC. Six patients including the case diagnosed to have RCC on repeat biopsy underwent radical nephrectomy in the nondiagnostic group. The histopathology revealed RCC in four, and angiomyelolipoma and pyelonephritis in one each. The remaining three nondiagnostic cases are under follow-up; there has been no change in the size of the lesions in a mean follow-up of 32 mo (range: 12-52). There has been no change in the size of benign lesions at a mean follow-up of 29 mo (range: 3-72). The procedure-related complication in the form of bleeding following biopsy was observed in one patient, which settled conservatively. There was no statistically significant difference (chi-square=1.134 and p value equal to 0.379) in the recurrence rate and metastases between the biopsy radical nephrectomy and nonbiopsy radical nephrectomy groups for the same stage of disease during the same period.

CONCLUSIONS

Image-guided biopsy is safe and accurately characterises indeterminate renal masses. A repeat biopsy protocol is useful in case of a nondiagnostic first biopsy. The long-term outcome following radical nephrectomy of biopsy-diagnosed RCC does not differ from the radiologically obvious RCC.

MRI of the kidney and urinary tract

MRI of the kidney and urinary tract has evolved with advancements in MR technology combined with further radiologic experience. A combination of simple pulse sequences and the use of gadolinium (Gd) allow a comprehensive evaluation of the genitourinary system and facilitate the detection and accurate characterization of renal and urinary tract masses. In this review an MRI technique used to evaluate the kidneys and urinary tract is presented with an emphasis on the characterization of renal masses.

Renal Masses in the Adult Patient: The Role of Percutaneous Biopsy

Although percutaneous renal mass biopsy with cross-sectional imaging guidance has long been considered to be safe and accurate, there have been recent advances in imaging, interventional, and cytologic techniques that have increased the role of percutaneous biopsy in the diagnosis of renal masses. Today, biopsy plays a fundamental role in the care of patients with a renal mass. Biopsy results are used to confirm the diagnosis of renal cancers, metastases, and infections, and there is increasing evidence to suggest that biopsy can help subtype and grade many primary renal cancers. Because a considerable fraction of small solid renal masses are benign and do not need treatment, there is an increasing need to diagnose them. Biopsy after a full imaging work-up can help prevent unnecessary and potentially morbid surgical and ablation procedures in a substantial number of patients. Although more data are needed to understand the overall accuracy of biopsy for the diagnosis of benign lesions, many can be diagnosed with the aid of biopsy findings. This article reviews reported experience with percutaneous renal mass biopsy, discusses the technical factors that contribute to results, and details seven specific clinical settings that should prompt the clinician to consider percutaneous biopsy when encountering a renal mass.

Computed tomography guided needle biopsy: experience from 1,300 procedures

CONTEXT AND OBJECTIVE

Computed tomography (CT) guided biopsy is widely accepted as effective and safe for diagnosis in many settings. Accuracy depends on target organ and needle type. Cutting needles present advantages over fine needles. This study presents experience from CT guided biopsies performed at an oncology center.

DESIGN AND SETTING

Retrospective study at Hospital do Câncer A. C. Camargo, São Paulo.

METHODS

1,300 consecutive CT guided biopsies performed between July 1994 and February 2000 were analyzed. Nodules or masses were suspected as primary malignancy in 845 cases (65%) or metastatic lesion in 455 (35%). 628 lesions were thoracic, 281 abdominal, 208 retroperitoneal, 134 musculoskeletal and 49 head/neck. All biopsies were performed by one radiologist or under his supervision: 765 (59%) with 22-gauge fine-needle/aspiration technique and 535 (41%) with automated 16 or 18-gauge cutting-needle biopsy.

RESULTS

Adequate samples were obtained in 70-92% of fine-needle and 93-100% of cutting-needle biopsies. The specific diagnosis rates were 54-67% for fine-needle and 82-100% for cutting-needle biopsies, according to biopsy site. For any site, sample adequacy and specific diagnosis rate were always better for cutting-needle biopsy. Among 530 lung biopsies, there were 84 pneumothorax (16%) and two hemothorax (0.3%) cases, with thoracic drainage in 24 (4.9%). Among abdominal and retroperitoneal biopsies, there were two cases of major bleeding and one of peritonitis.

CONCLUSION

Both types of needle showed satisfactory results, but cutting-needle biopsy should be used when specific diagnosis is desired without greater incidence of complications.

FDG PET in solitary metastastic/secondary tumor of the kidney: A report of three cases and a review of the relevant literature

Metastatic tumors or secondary lymphoma of the kidney are rare and can often be missed on conventional computed tomography (CT) imaging. On the other hand, many types of metastatic tumor or lymphoma can be detected clearly as hotspots of elevated uptake on FDG PET. However, excreted FDG present in the urinary tract mimics these findings and interferes with image reading. Careful investigation of the renal cortex by FDG PET and review of anatomical images, such as the findings of CT and MRI, have important roles in the detection of renal tumor. Here, we present three cases of solitary metastatic/secondary tumor of the kidney, and discuss the features of the lesions on FDG PET in comparison with their appearance on CT.

How I Do It: Evaluating Renal Masses

With modern computed tomography (CT) and magnetic resonance (MR) imaging equipment, the diagnosis of most renal masses is usually straightforward and accurate. The major question to be answered is whether the mass represents a surgical or nonsurgical lesion or, in some cases, if follow-up studies are necessary. This evaluation usually can be accomplished if a high-quality examination is performed, if the clinical history of the patient is kept in mind, if conditions that mimic a renal neoplasm are considered and excluded, and if there is an awareness of the potential pitfalls and limitations of CT and MR imaging. In this article, the authors present their technique in the performance of CT and MR imaging examinations, summarize their approach to the diagnosis of renal masses, review the imaging findings in these lesions, and stress the limitations in renal mass diagnosis.

Laparoscopic nephroureterectomy for upper urinary tract transitional cell carcinoma: is it better than open surgery?

OBJECTIVE

In 1991, laparoscopic nephroureterectomy has been introduced as a treatment option for upper tract transitional cell carcinoma. Based on the review of the current literature and personal experience we want to analyze the actual results of this technique in comparison to open surgery.

MATERIALS AND METHODS

We performed a MEDLINE/PubMed search and reviewed the literature on laparoscopic and open nephroureterectomy between 1991 and 2004 (n = 1365 patients) including the results of 45 patients who underwent either laparoscopic (n = 23) or open nephroureterectomy (n = 21) during the same period of time at the Klinikum Heilbronn. Demographic, perioperative and follow-up data were compared.

RESULTS

The analysis revealed a slightly longer OR-time (276.6 vs. 220.1 min), and significantly lower blood loss (240.9 vs. 462.9 ml) in the laparoscopic series. No differences of minor (12.9 vs. 14.1%) or major complication rate (5.6 vs. 8.3%) were observed. All nine comparative studies revealed a significant dose reduction of the morphine-equivalents after laparoscopy. In all ten comparative series the hospital stay was shorter after laparoscopy, but only in 6 series the difference was statistically significant. The frequency of bladder recurrence (24.0 vs. 24.7%), local recurrence (4.4 vs. 6.3%), and distant metastases (15.5% vs. 15.2) did not differ significantly in both groups. The actual disease-free two-year survival rates (75.2 vs. 76.2%) were similar. The five-year survival rates averaged 81.2% in the three laparoscopic (n = 113 pat.) and 61% in the ten open series (n = 681 pat.) Six port site metastases were reported in 377 (1.6%) analyzed patients occurring 3 to 12 months following laparoscopy.

CONCLUSION

Open radical nephroureterectomy still represents the golden standard for the management of upper tract transitional cell carcinoma, however, laparoscopic radical nephroureterectomy offers the advantages of minimally invasive surgery without deteriorating the oncological outcome. In case of advanced tumors (pT3,N+) open surgery is still recommended.

A renal mass in the setting of a nonrenal malignancy: When is a renal tumor biopsy appropriate?

BACKGROUND

Frequently, a renal mass is identified when patients with cancer undergo studies for staging or surveillance. In determining whether it represents a metastasis, patients are frequently subjected to percutaneous renal biopsies. The authors evaluated their experience with this dilemma to formulate management guidelines.

METHODS

The authors reviewed the medical records of 100 consecutive patients with nonrenal malignancies diagnosed with renal masses at presentation or follow-up. Renal mass histology was available for all patients after nephrectomy or biopsy. Clinical characteristics were assessed to identify factors predictive for a renal metastasis versus a primary renal neoplasm.

RESULTS

The only factors predictive of a metastasis to the kidney were progression of the nonrenal malignancy and lack of enhancement of the renal mass (P < 0.0001). Forty-six patients (46%) had evidence of progression of their nonrenal malignancy in addition to the renal mass. In these patients, the probability of a metastasis to the kidney was 86% (95% confidence interval [CI], 57.2-98.2%) without renal mass enhancement and 32% (95% CI, 14-55%) with enhancing renal masses. None of the 54 patients without signs of progression of their nonrenal malignancy proved to have metastases to the kidney, regardless of the imaging characteristics of the mass (zero probability; 95% CI, 0-7%; P < 0.001).

CONCLUSIONS

In patients presenting with renal masses and another clinically localized malignancy, renal mass biopsies were not indicated, as the mass rarely represented a metastasis. These patients may opt for close surveillance or extirpation based on the prognosis of their nonrenal malignancy.

Atypical thymoma: A report of seven patients

BACKGROUND

Most thymic neoplasms fall under the designation of thymoma, consisting of well-differentiated epithelial cells, resembling normal thymus. At the opposite spectrum are thymic carcinomas; the cell of origin while similar is malignant. Recently a third category of thymic neoplasms, atypical thymomas, has been recognized representing thymic neoplasms manifesting atypia although without overt cytomorphologic criteria of malignancy.

METHODS

Seven patients with a diagnosis of atypical thymoma were encountered over a 6-year period from the patient files of the cardiothoracic division of The Ohio State Medical Center.

RESULTS

In all patients there was gross or light microscopic invasive disease with involvement of the capsule, phrenic nerve, diaphragm, chest wall, and lung. Surgical extirpation/de-bulking along with radiation therapy in six and chemotherapy in one led to complete disease regression. Intrathoracic recurrences developed in 4 involving lung, pleura, chest wall and diaphragm. All patients are well.

CONCLUSIONS

Atypical thymomas are locally aggressive tumors with a high incidence of intrathoracic recurrence; extrathoracic spread is not seen. Our study corroborates other reports that death attributable to atypical thymoma is uncommon.

Prospective analysis of computerized tomography and needle biopsy with permanent sectioning to determine the nature of solid renal masses in adults

PURPOSE

We prospectively determined the accuracy of computerized tomography (CT) and needle biopsy of solid renal masses.

MATERIALS AND METHODS

A total of 100 patients with a solid renal mass who were scheduled for operation were prospectively evaluated. CT was performed before radical or partial nephrectomy. Biopsy of the surgical specimens was done twice through the tumor using an 18 gauge biopsy gun. Specimens were sent for permanent section and review by 2 pathologists blinded to each other and to the whole tissue specimens. Images were reviewed by 2 radiologists blinded to each other and to the results of pathological analysis. Results of CT and permanent biopsy were compared with the results of whole tissue specimen analysis.

RESULTS

Specimens were obtained from 59 radical and 41 partial nephrectomies. Malignant neoplasms were present in 85 patients (85%). Overall accuracy was 77% and 72%, the nondiagnostic rate was 20% and 21%, sensitivity was 81% and 83%, and specificity was 60% and 33%. For the 2 radiologists overall accuracy was 60% and 66%, the nondiagnostic rate was 31% and 23%, sensitivity was 70% and 77%, and specificity was 20% and 20%, respectively.

CONCLUSIONS

Overall permanent biopsy results were accurate in more than 72% of cases and CT was accurate in more than 60%. However, because the nondiagnostic rate for CT and needle biopsy was 20% and 31%, respectively, and specificity was low, we do not recommend routine preoperative CT and subsequent needle biopsy to guide treatment decision making. Rather, cases must be decided individually.

Evaluation of sonographically guided percutaneous core biopsy of renal masses

OBJECTIVE

Our objective was to determine the utility of sonographically guided percutaneous core biopsy to evaluate renal masses.

MATERIALS AND METHODS

We conducted a retrospective analysis of our imaging-guided procedures from January 1999 to June 2001. We performed 26 sonographically guided percutaneous core biopsies of renal masses in 26 patients. From two to five specimens were obtained from a single mass in each patient using an 18-gauge automated biopsy system. We examined the patients' medical records, pathology results, and imaging studies. Core biopsy results were compared with surgical pathology (n = 6) or clinical follow-up (n = 20).

RESULTS

All biopsies provided sufficient material for analysis. Biopsy findings were positive for malignancy in 19 (73%) of 26 masses. Histologic diagnoses included renal cell carcinoma were (n = 11), metastasis (n = 3), lymphoma (n = 2), and transitional cell carcinoma (n = 2). Specific cell type characterization could not be made on one biopsy, but the specimens were highly suspicious for malignancy. Biopsy revealed seven (27%) of 26 benign diagnoses: oncocytoma (n = 3), angiomyolipoma (n = 2), and fibrosis (n = 2). The average follow-up period for patients with benign diagnoses was 10 months. One case of surgically proven necrotic pyelonephritis was mischaracterized as fibrosis at core biopsy. Sonographically guided percutaneous core biopsy of renal masses showed a sensitivity of 100% and a specificity of 100% for the diagnosis of malignancy. The core specimens yielded a specific diagnosis in 92% (24/26) of masses. No immediate complications occurred after the procedure. One patient developed a pseudoaneurysm that presented 3 months after the biopsy. CONCLUSION. Sonographically guided percutaneous core biopsy is a reliable and accurate method for evaluating renal masses.

Needle-tract implantation following us-guided fine-needle aspiration biopsy of transitional cell carcinoma of the bladder, urethra, and prostate

Localized tumor implantation of the ventral abdominal wall was found at 2, 5, and 8 months following percutaneous ultrasound-guided fine-needle aspiration biopsy (FNAB) of transitional carcinoma of the bladder, urethra, or prostate in 3 dogs. To our knowledge this complication has not been reported in dogs following FNAB. Despite the rarity of needle-tract implantation, the potential for this complication with transitional cell carcinomas is apparently not negligible and warrants consideration. We recommend traumatic urethral catheterization to obtain a cytologic diagnosis of potential transitional cell carcinomas of the lower urinary tract or prostate whenever possible until more information becomes available. However, needle-track implantation is so rare that it should not influence the decision to perform a percutaneous FNAB if the urethra cannot be catheterized.

Fine-needle percutaneous biopsy of renal masses with helical CT guidance

PURPOSE

To evaluate the feasibility, accuracy, and clinical role of fine-needle percutaneous biopsy of renal masses, with helical computed tomographic (CT) guidance.

MATERIALS AND METHODS

In 63 patients (mean age, 62 years), 73 biopsies were performed. The median tumor size was 4.0 cm. Tumor biopsy was performed with an 18-gauge needle by using helical CT guidance in an outpatient setting. Two to four cores per tumor were obtained.

RESULTS

Biopsy material was insufficient for analysis in 15 (21%) procedures. The median tumor size of failed or successful biopsies was 3.0 or 4.8 cm, respectively (P =.03). A benign lesion was found at eight biopsies. Two samples were suspicious for renal cell carcinoma (RCC). RCC was found in 38 biopsy samples. The remainder were transitional cell carcinoma, metastasis, lymphoma, or sarcoma. Twenty-six patients underwent nephrectomy. The accuracies of biopsy for histopathologic and Fuhrman nuclear grade evaluation were 89% and 78%, respectively. For tumors of 3.0 cm or smaller or larger than 3.0 cm, 37% (11 of 30) or 9% (four of 43) had failure of biopsy, respectively (P =.006). No substantial morbidity occurred.

CONCLUSION

Fine-needle biopsy with helical CT guidance is accurate for the histopathologic evaluation of renal masses without morbidity. Indications are renal lesions that do not have the typical radiologic features of RCC, Bosniak category III or IV cystic lesions, and locally advanced or metastatic RCC.

Imaging guided biopsies of renal masses

Percutaneous fine-needle aspiration biopsy can be used for the diagnosis of many abdominal masses. It is safe and accurate, and is often all that is necessary to determine treatment. Fine-needle aspiration biopsy is both accurate and cost-effective, comparing favorably with open surgical biopsy. The use of percutaneous biopsy for the diagnosis of renal masses is now more commonplace as urologists and radiologists become familiar with its indications, contraindications, accuracy and complications.