JOURNAL OF ENDOUROLOGY Volume 22, Number 10, October 2008 © Mary Ann Liebert, Inc. Pp. 2377–2380 DOI: 10.1089/end.2008.9724
Number of Needle Passes Does Not Correlate with the Diagnostic Yield of Renal Fine Needle Aspiration Cytology Sero Andonian, M.D.,1 Zeph Okeke, M.D.,1 Deidre A. Okeke,1 Chiara Sugrue, M.D.,2 Patricia G. Wasserman, M.D.,2 and Benjamin R Lee, M.D.3
Abstract
Background and Purpose: Renal Fine Needle Aspiration Cytology (FNAC) has gained popularity due to increasing options in management of renal lesions such as energy ablation and active surveillance. The diagnostic yield of renal FNAC varies between 40–90%. We hypothesized that adequate and diagnostic FNA samples would be associated with higher number of needle passes and higher number of slides examined. Patients and Methods: The pathology database at our institution was retrospectively searched for renal FNACs performed between 1995 and 2005. Patient gender, side, indication, cytological diagnosis, final histological diagnosis when available, number of needle passes performed, number of slides examined, and adequacy of the FNAC sample as determined by Diff Quik staining by the cytotechnologist (CS) were recorded. Chi square test was performed for statistical analysis. Results: Out of 377 renal biopsies performed, 259 were core biopsies for medical renal disease, and 118 were FNACs for renal lesions, including 16 for indeterminate complex renal cysts and 102 for solid renal masses. Indeterminate renal cysts were excluded from the study. Out of 102 FNACs for solid renal masses, 22 were inadequate with 13 (59%) being non-diagnostic; and 80 FNACs were adequate with 3 (4%) being non-diagnostic. The number of needle passes was not significantly different between non-diagnostic and diagnostic samples (2.5 vs 3.2); and between inadequate and adequate samples (3.4 vs 3.0). Similarly, the number of slides examined was not significantly different between non-diagnostic and diagnostic samples (9.5 vs 10.9); and between inadequate and adequate samples (11.3 vs 10.6). Diff Quik adequate samples had significantly higher diagnostic yields when compared to Diff Quik inadequate samples (965 vs 41%; p 0.01). Conclusions: The number of needle passes and microscopic slides examined did not correlate with sample adequacy or diagnostic yield of renal FNAC. Sample adequacy as determined by Diff Quik staining correlated with diagnostic FNAC. Despite the retrospective nature of this study, a cytotechnologist should be present during the FNA procedure to ensure adequate samples have been obtained to increase the diagnostic yield of renal FNAC.
Introduction
M
ANAGEMENT OPTIONS FOR RENAL lesions have undergone reexamination with the advent of active surveillance and energy ablation therapies either percutaneously or laparoscopically.1 This is in line with increasing incidence of incidental renal masses as a result of increased abdominal imaging.2,3 These new options have necessitated accurate diagnosis and follow-up of these incidental renal lesions. Therefore, there is a renewed interest in renal Fine Needle
1Smith
Aspiration Cytology (FNAC) for both diagnosis and followup of these lesions. However, FNAC has suffered from a wide range of diagnostic yields. The lowest diagnostic yield was 40% when 2 passes of a 22G needle was used without determination of adequacy of the sample by a cytotechnologist.4 In a recent review of the literature on renal mass biopsies combining both core biopsies and FNACs found that the technical failure rate due to insufficient sample ranged from 0 to 22% with an average rate of 8.9%.1 Recently, we found the technical failure rate of 19% for indeterminate complex
Institute of Urology, 2Department of Pathology, North Shore-Long Island Jewish Health System, New Hyde Park, New York. of Urology, Tulane University, New Orleans, Louisiana.
3Department
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ANDONIAN ET AL. TABLE 1.
THE NUMBER
OF
NEEDLE PASSES AND NUMBER OF SLIDES EXAMINED ACCORDING DIAGNOSTIC YIELD OF THE SAMPLE
TO THE
No. of needle passes and slides No. of passes, ave (range) No. of slides, ave (range)
Non-diagnostic sample
Diagnostic sample
P-value
2.5 (1–5)0 9.5 (2–30)
3.2 (1–12) 10.9 (2–26)
0.16 0.44
cysts and 16% for solid renal masses.5 However, factors determining the diagnostic yield of renal FNACs are unclear. Therefore, the aim of the present study was to determine whether the average amount of cystic fluid aspirated and the number of passes for solid renal lesions determine adequacy of the sample and the diagnostic yield. Furthermore, we sought to determine whether the number of slides examined differed with adequacy of the sample and definitive diagnosis. We hypothesized that adequate and diagnostic FNA samples would be associated with a higher number of needle passes and higher number of slides examined. Patients and Methods The pathology database of Long Island Jewish Medical Center was searched for renal biopsies performed between 1995 and 2005. There were a total of 377 renal biopsies. Out of these, 259 were core biopsies for medical renal disease, 16 were FNACs for indeterminate complex renal cysts, and 102 were FNACs for solid renal masses. In the present study, renal FNACs for solid renal lesions were included. Indications for FNACs of solid renal masses were: 60 with previous history of malignancy, 17 with suspected metastatic renal cell carcinoma, 13 with significant medical co-morbidities, 4 with multiple bilateral renal masses, 2 with suspected abscesses, and 6 with other diseases associated with renal lesions. Out of 102 FNACs included in this study, 67 (66%) were males and 35 (34%) were females. The mean age was 65.4 years (2 years to 101 years). In 52 patients, the lesion was on the right, in 49 patients, the lesion was on the left, and in one patient, laterality was unknown. All FNACs, except for 7 (6 open and 1 ultrasound-guided), were performed using CT guidance. A 22G needle was used to aspirate cytology specimen from solid renal masses. A cytotechnologist (CS) was present in all FNACs to determine the adequacy of the collected specimen by Diff Quik staining of air-dried sample. This method for specimen processing has been previously described.5,6 In certain cases, the procedure was terminated prior to obtaining adequate sample due to patient discomfort or technical difficulties. The rest of the cytological specimens were stained using Papanicolaou and Ultrafast Papanicolaou techniques.6 For inconclusive diagnosis, immunocytochemistry was performed with differ-
TABLE 2.
THE NUMBER
OF TO
No. of needle passes and slides No. of passes, ave (range) No. of slides, ave (range)
ent markers (Vimentin, CK7, CD10, CD 117, cytokeratin AE1.3, CK20, CEA, p63, TIF-1, SMA, Melan A, Cam 5.2, HMB45, CD 20, AFP, EMA, TFE-3). For solid renal masses, the number of needle passes was recorded in addition to the number of slides examined, adequacy of the specimen, cytological diagnosis, and when available the final histopathological diagnosis. For all patients, age, cytology case number, date of the procedure, referring physician, indication for biopsy, and type of imaging used (CT, ultrasound or open) were recorded. Cytospin and cell block slides examined were also included in the database. The total number of slides examined was recorded in the database. Student t-test was used to calculate two-tailed p values for continuous variables in Tables 1 and 2. Chi square and Fisher exact tests were used to calculate the p-value for the dichotomous variables in Table 3. Results Out of 102 FNACs for solid renal masses, 22 were inadequate with 13 (59%) non-diagnostic and 80 FNACs were adequate with 3 (4%) non-diagnostic. The average number of needle passes was 2.5 and 3.2 in non-diagnostic and diagnostic FNACs, respectively (p 0.05). The average number of slides examined did not differ significantly between nondiagnostic and diagnostic FNACs (9.5 vs 10.9; p 0.05) (Table 1). Similarly, the average number of needle passes was not significantly different between inadequate and adequate FNAC groups (3.4 vs 3.0; p 0.05). The average number of slides examined were similar when inadequate and adequate FNACs were compared (11.3 vs 10.6; p 0.05) (Table 2). Therefore, for solid renal lesions, the number of passes and the number of slides examined did not determine adequacy of the FNAC sample nor its diagnostic yield. However, Diff Quik adequacy of the FNAC sample correlated with diagnostic yield (p 0.01) (Table 3). Discussion With recent increase in utilization of renal FNACs for diagnosis and follow-up of incidental renal lesions, there have been increasing reports of diagnostic yields of renal FNACs. Unfortunately, the diagnostic yield of renal FNAC varies be-
NEEDLE PASSES AND NUMBER OF SLIDES EXAMINED ACCORDING DIFF QUIK ADEQUACY OF THE SAMPLE Inadequate sample
Adequate sample
P-value
3.4 (1–12) 11.3 (2–30)
3.0 (1–6) 10.6 (2–26)
0.47 0.64
NUMBER OF NEEDLE PASSES DOES NOT CORRELATE WITH FNAC TABLE 3.
DIAGNOSTIC
Sample Diff Quik adequate Diff Quik inadequate
AND
NON-DIAGNOSTIC FNACS ACCORDING
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TO
DIFF QUIK ADEQUACY
OF THE
SAMPLE
Diagnostic FNAC
Non-Diagnostic FNAC
P-value
77 (96%) 9 (41%)
3 (4%) 13 (59%)
0.01
tween 40–90%. A recent review article combining both core biopsies and FNACs found the non-diagnostic rate due to technical failure (inability to obtain sufficient cells for diagnosis) to range from 0–22% with an average rate of 8.9%.1 However, factors determining the success of FNACs were not analyzed. Recently, a retrospective review from our institution revealed that the non-diagnostic rate for indeterminate complex cysts was 19% and for solid renal lesions was 16%.5 In the present study, FNACs for solid renal lesions were retrospectively analyzed to determine whether the number of needle passes or the number of pathology slides examined influenced the adequacy of the sample obtained or the non-diagnostic rate. Interestingly, the number of needle passes and the number of pathology slides examined did not significantly defer whether the FNAC sample was adequate or diagnostic. Therefore, the hypothesis that increased number of needle passes and slides examined determine adequacy and diagnostic yield was rejected. This has not been previously reported. The finding that adequacy of the FNA sample was predictive of diagnosis, has been previously reported. For example, when 2 needle passes of renal masses were analyzed without the presence of a cytotechnologist, this yielded the lowest diagnostic rate of 40%.4 However, when a cytotechnologist is present to determine adequacy of the sample by Diff Quik staining, the technical failure rate of FNAC has been reported to vary between 6% and 20%.7–9 In the largest series of 583 renal FNACs, the non-diagnostic rate of 24% was reported.10 However, this series extended over a span of 30 years with variable imaging modalities and techniques.11 Several factors determine success of FNACs. The most important is the technique and experience of the performer.12 Tumor size is another factor. Large tumors have a central necrotic area which should be avoided, while small lesions are harder to localize.1 For example, FNACs for tumors less than 3 cm and larger than 6 cm have lower diagnostic yields.13 Furthermore, it is important to note that a dedicated cytotechnologist (CS) was present during all FNA procedures. When a cytotechnologist is not available, then core biopsies should be obtained.9 Finally, it is important to use a guiding cannula to minimize contamination with blood and decrease the risk of tract seeding, although this has been reported in only 6 cases of renal cells carcinoma.14–19 Limitations of the current study include the fact that it was based on retrospective review of the pathology database. The operator may have terminated the procedure prior to obtaining adequate sample due to technical difficulties or patient discomfort. Furthermore, clinical information on the size of the solid renal lesions are unknown and could not be correlated with the number of the needle passes or the diagnostic rate. Furthermore, small sample size may have contributed to the insignificant difference in between the groups.
Larger sample of patients with increasing number of needle passes and slides examined are needed to confirm these results. Conclusion The number of needle passes and microscopic slides examined did not correlate with adequacy or diagnostic yield of renal FNAC. Sample adequacy as determined by Diff Quik staining correlated with diagnostic yield. Therefore, a cytotechnologist should be present during the procedure to ensure adequate samples have been obtained to increase the diagnostic yield of renal FNAC. Disclosure Statement No competing interests exist. Acknowledgments This work was supported in part by grants from the Quebec Urological Association Foundation and Frank McGill Travel Fellowship to Sero Andonian. References 1. Lane BR, Samplaski MK, Herts BR, et al. Renal mass biopsy—a renaissance? J Urol. 2008; 179:20. 2. Hollingsworth JM, Miller DC, Daignault S, Hollenbeck BK. Rising incidence of small renal masses: a need to reassess treatment effect. J Natl Cancer Inst. 2006; 98:1331. 3. Chow WH, Linehan WM, Devesa SS. Re: Rising incidence of small renal masses: a need to reassess treatment effect. J Natl Cancer Inst. 2007; 99: 569. 4. Campbell SC, Novick AC, Herts B, et al. Prospective evaluation of fine needle aspiration of small, solid renal masses: accuracy and morbidity. Urology.1997; 50:25. 5. Andonian S, Okeke Z, VanderBrink BA et al. Etiology of Non-Diagnostic Renal FNACs in a Contemporary Series. BJU; in press. 6. Allen KA. A Guide to preparation. Chicago: ASCP, 1995. 7. Truong LD, Todd TD, Dhurandhar B, Ramzy I. Fine-needle aspiration of renal masses in adults: analysis of results and diagnostic problems in 108 cases. Diagn Cytopathol 1999; 20:339. 8. Wood BJ, Khan MA, McGovern F, et al. Imaging guided biopsy of renal masses: indications, accuracy and impact on clinical management. J Urol. 1999; 161:1470. 9. Heilbrun ME, Zagoria RJ, Garvin AJ, et al. CT-guided biopsy for the diagnosis of renal tumors before treatment with percutaneous ablation. AJR Am J Roentgenol. 2007; 188:1500. 10. Richter F, Kasabian NG, Irwin RJ Jr, Watson RA, Lang EK. Accuracy of diagnosis by guided biopsy of renal mass lesions classified indeterminate by imaging studies. Urology. 2000; 55:348.
2380 11. Siegel CL. Accuracy of diagnosis by guided biopsy of renal mass lesions classified indeterminate by imaging studies. J Urol. 2001; 165:322. 12. Volpe A, Kachura JR, Geddie WR, et al. Techniques, safety and accuracy of sampling of renal tumors by fine needle aspiration and core biopsy. J Urol. 2007; 178:379. 13. Rybicki FJ, Shu KM, Cibas ES, et al. Percutaneous biopsy of renal masses: sensitivity and negative predictive value stratified by clinical setting and size of masses. AJR Am J Roentgenol. 2003; 180:1281. 14. Gibbons RP, Bush WH, Burnett LL. Needle tract seeding following aspiration of renal cell carcinoma. J Urol. 1977; 118:865. 15. Kiser GC, Totonchy M, Barry JM. Needle tract seeding after percutaneous renal adenocarcinoma aspiration. J Urol. 1986; 136:1292. 16. Shenoy PD, Lakhkar BN, Ghosh MK, Patil UD. Cutaneous seeding of renal carcinoma by Chiba needle aspiration biopsy. Case report. Acta Radiol. 1991; 32:50. 17. Auvert J, Abbou CC, Lavarenne V: Needle tract seeding following puncture of renal oncocytoma. Prog Clin Biol Res. 1982; 100:597. 18. Wehle MJ, Grabstald H. Contraindications to needle aspiration of a solid renal mass: tumor dissemination by renal needle aspiration. J Urol. 1986; 136:446.
ANDONIAN ET AL. 19. Abe M, Saitoh M. Selective renal tumour biopsy under ultrasonic guidance. Br J Urol. 1992; 70:7.
Address reprint requests to: Benjamin R. Lee, M.D. Department of Urology Tulane University New Orleans, Louisiana E-mail:
[email protected]
Abbreviations Used ave CT FNAC ICC RCC TCC
average computed tomography fine needle aspiration cytology immunocytochemistry renal cell carcinoma transitional cell carcinoma
