Tumors of the Anterior Prostate: Implications for Diagnosis and Treatment.

Tumors of the anterior prostate (ie, the portion of the prostate anterior to the urethra) account for approximately 20% of all prostate cancers. Although anterior prostate cancers frequently occur, they have historically been underdetected because of infrequent sampling. Recent advances in multiparametric magnetic resonance imaging and improved biopsy schemes have significantly increased our diagnostic accuracy for detecting anterior tumors. Herein, we review these developments and highlight key aspects of the diagnosis and management of anterior prostate cancers.

Accuracy and implications of percutaneous renal biopsy in the management of renal masses.

INTRODUCTION: Percutaneous renal biopsy in patients with renal masses is increasing. We investigated the accuracy of percutaneous renal mass biopsy results in patients undergoing evaluation of solid renal masses. METHODS: A retrospective review was performed of patients in the Kaiser Permanente Southern California Region who underwent computed tomography or ultrasound-guided percutaneous renal biopsy of a solid renal mass between January 2005 and December 2009. Patients were stratified by size of mass (≤ 4 cm vs > 4 cm). Initial biopsy results were correlated with final pathology specimens after extirpation. RESULTS: Medical records of 126 patients (129 renal units with 132 biopsies) were reviewed. Initial diagnostic biopsies revealed 87 (66%) malignant, 38 (29%) benign, and 7 (5%) nondiagnostic lesions. Sixty-three patients (50%) ultimately underwent extirpative surgery (23 partial and 40 radical nephrectomies). Of these patients, the diagnostic accuracy of the initial percutaneous renal mass biopsy was 76%, with an overall sensitivity and specificity of 75.4% and 100%, respectively. The biopsy concordance to final histologic tumor subtype was 93%. Larger tumor size (odds ratio [OR], 2.20; 95% confidence interval [CI], 0.55 to 8.88) and increasing number of biopsies (OR, 2.50; 95% CI, 0.59 to 10.69) were associated with increasing accuracy of a biopsy result to predict cancer; however, these associations were not statistically significant. CONCLUSION: Percutaneous renal mass biopsy is diagnostically accurate and has good sensitivity, specificity, and concordance with final pathologic renal cell carcinoma subtype. This diagnostic modality can assist in management of select renal masses as treatment options are expanding.

Ex vivo lymphatic mapping: a technique to improve pathologic staging in colorectal cancer.

Sentinel lymph node (SLN) biopsy is widely used for solid tumors and has been proposed for use in staging colorectal cancer (CRC). Few studies have examined the ex vivo lymphatic mapping (EVLM) technique for staging CRC. We hypothesized that EVLM is technically feasible, sensitive, accurate, and improves the staging of CRC. After standard resection for colorectal cancer, 1 mL of isosulfan blue dye was injected circumferentially around the tumor. Blue-stained nodes were dissected separately and examined by hematoxylin and eosin (H&E) and immunohistochemical (IHC) stains. Routine pathologic evaluation was performed on all other harvested lymph nodes. Forty patients underwent 43 cancer resections with EVLM from July 2000 to December 2003. SLN were identified in 39 of 43 (91%) specimens. The mean number of SLN obtained was 1.9 (range, 0-5). Pathologic evaluation demonstrated nodal metastasis in 16 of 39 (39%) specimens. The SLN was tumor-positive in 9 of these 16 (56%) patients. The overall accuracy of EVLM was 82%. Two patients (9%) with H&E node negative disease were upstaged when found to have micrometastases by IHC staining. In conclusion, EVLM is technically possible in 90 per cent of patients with CRC. Although overall accuracy was high, the SLN status correlated poorly with the true nodal status of the CRC. However, EVLM improves pathologic staging in 9 per cent of patients and therefore may be of value in CRC.

Does tumor burden limit the accuracy of lymphatic mapping and sentinel lymph node biopsy in colorectal cancer?

PURPOSE: Sentinel lymph node (SLN) biopsy is a widely accepted method for staging breast cancer and melanoma, and it has recently been proposed as a means of improving staging in colorectal cancer. However, lymphatic mapping in colorectal cancer has been plagued by studies demonstrating high false-negative rates. The purpose of this study was to evaluate possible mechanisms for high false-negative rates after SLN biopsy in colorectal cancer. We hypothesized that poor accuracy may be due to bulky tumor or complete replacement of lymph nodes by tumor. PATIENTS AND METHODS: Patients with colorectal adenocarcinoma underwent standard colorectal resection with lymphatic mapping. At operation, 1 mL of isosulfan blue dye was injected at the tumor site, using either an in vivo or an ex vivo technique. Routine pathological evaluation was performed. The sentinel node was examined by hematoxylin and eosin stains, and if these results were negative, by cytokeratin immunohistochemistry. The patient's age, operation type, tumor stage, tumor diameter, method of SLN detection, presence of palpable nodes, and pathological description of nodes completely replaced by tumor were recorded. RESULTS: Fifty patients (mean age, 62.8, 50% men) undergoing colorectal cancer resection underwent 51 lymphatic mapping procedures. Right- and left-sided colorectal resections were almost equally distributed (48% vs 42%). SLNs were successfully identified in 47 of 51 specimens (92%). The mean number of SLNs obtained from each specimen was 1.5 (range, 1-5). Routine pathological evaluation demonstrated lymph node metastasis in 20 of the 47 patients (43%) who had an SLN identified. The SLN was positive for metastasis in 10 of these 20 patients (50%). Ten of 20 patients with metastatic disease had a negative SLN, resulting in a false-negative rate of 50%. The false-negative rate was significantly higher in patients undergoing left-sided procedures versus right-sided procedures. Differences among gender, tumor stage, tumor diameter, method of SLN detection, presence of palpable nodes, and pathological description of nodes completely replaced by tumor were not associated with a higher false-negative rate. DISCUSSION: Identification of the SLN in colorectal cancer is technically possible in more than 90% of patients. However, SLN status correlates poorly with the true nodal status of the colorectal cancer, and the false-negative rate is 50%. This high false-negative rate is not clearly explained by extensive tumor burden, and it was also independent of gender, tumor stage, and type of lymphatic mapping technique. However, staging accuracy was lower in patients who underwent left-sided colorectal resection. Further studies are needed to clarify the limitations of lymphatic mapping in colorectal cancer.