RENAL CYSTS AND CYSTIC NEOPLASMS

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.

MR evaluation of solid renal masses

After diagnosis of a suspicious renal mass on ultrasound or CT, renal MR imaging typically is ordered to characterize the mass further, stage the mass, or resolve discordant ultrasound and CT results. MR imaging may also be ordered in cases in which ultrasound is poor or in instances in which contrast-enhanced CT may be ill advised.

Volumetric measurement of renal cysts and parenchyma using MRI: phantoms and patients with polycystic kidney disease

We have developed an MR method to measure the volumes of renal cysts and parenchyma in patients with polycystic kidney disease. Phantoms were designed to simulate polycystic kidneys. Four patients were recruited. MR scans were performed on the phantoms and patients. A stereology technique was applied for image segmentation and volume measurement. Volumetric measurement of renal cysts and parenchyma was accurate in phantom studies and reliable in both phantom and patient studies in these limited examples.