Pathologic examination of renal cell cancer by means of step-sectioning

Prospective study of safety margins in partial nephrectomy: Intraoperative assessment and contribution of frozen section analysis

OBJECTIVES

To evaluate prospectively a healthy parenchymal safety margin during conservative surgery for renal cell carcinoma.

METHODS

From 1997 to 2001, elective nephron-sparing surgery was performed through a flank incision in 61 consecutive patients (mean age 59.4 years, range 34.2 to 78.5). The mean tumor size was 32 mm (range 12 to 50). The tumor localization was juxtahilar in 10 and distant in 51. Prospective margin assessment used the following protocol. Margins were evaluated macroscopically by the surgeon, controlled by frozen section analysis, and subsequently measured during histologic examination. All patients were monitored with computed tomography scans, with a mean follow-up of 72.5 months (range 46 to 95).

RESULTS

The histologic type was clear cell in 42 patients, papillary in 17, and chromophobic cell in 2. Of the 61 patients, 57 had 1997 TNM Stage pT1 and 4 had Stage pT2. The Furhman grade was grade 1 in 16, grade 2 in 35, and grade 3 in 10. No tumor margin was positive. Frozen section analysis and routine histologic examination yielded 53 complete and 8 incomplete margins compared with 51 and 10, respectively, as assessed by the surgeons. The mean peritumoral margin was 7 mm (range 4 to 10) for the cortex and 2 mm (range 0 to 5) for the deep part. No patient developed locoregional or metastatic relapse.

CONCLUSIONS

No apparent relationship was observed between peritumoral margin width and the risk of disease progression, even for tumors abutting the hilum, rendering illusory a safety margin greater than 1 cm. Although the surgeons' macroscopic margin evaluations were accurate, frozen section analysis is mandatory when the margin status is in doubt. In all cases, margin negativity remains an oncologic imperative.

Intraoperative pathology consultation for kidney and urinary bladder specimens

CONTEXT

Intraoperative pathology consultation for kidney and urinary bladder specimens is relatively infrequent. Scant literature is devoted to this topic.

OBJECTIVE

The clinical indications and diagnostic usefulness and pitfalls of intraoperative pathology consultation of kidney and urinary bladder specimens will be reviewed, based on literature and personally encountered cases.

DATA SOURCES

The indications for intraoperative pathology consultation for renal lesions included (1) surgical margins in partial nephrectomy specimens, (2) solid renal mass in unusual clinical or radiologic settings, (3) synchronous renal and extrarenal masses, (4) cystic renal lesions, (5) ureteral surgical margin for transitional cell carcinoma, (6) multiple renal masses, (7) solid mass in a diffusely cystic kidney, and (8) evaluation of renal injury. The indications for urinary bladder included (1) status of the surgical margins, (2) diagnosis of bladder tumor biopsy, (3) diagnosis of extravesical tumors with vesical extension, (4) diagnosis of extravesical mass, including pelvic lymph nodes encountered during cystectomy, and (5) status of bladder neck margin during radical prostatectomy for cancer. The frequent problematic areas for the kidney included misdiagnosis or incorrect classification of cystic tumors or spindle cell tumors, and confusion of clear cell renal cell carcinoma with inflammatory lesions. The problematic areas for urinary bladder included the differential diagnoses of high-grade dysplasia/carcinoma in situ with reactive changes at the ureteral or urethral surgical margins.

CONCLUSIONS

Distinctive indications and diagnostic pitfalls are recognized for intraoperative consultation of renal or urinary bladder lesions. Awareness of the pertinent problems should improve diagnostic accuracy and facilitate the proper management of these lesions.