Nodular hyperplasia in the peripheral zone of the prostate gland

Exophytic benign prostatic hyperplasia presenting as a polycystic pelvic mass

We report a case of an exophytic benign prostatic hyperplasia presenting as a polycystic pelvic mass. A 69-year-old man presented with an incidental finding of a pelvic mass of over 18 years. Digital rectal examination revealed a mass on the right anterior rectal wall 8 cm from the anal opening. His current prostate-specific antigen was 3.187 ng/mL. Enhanced computed tomography and magnetic resonance imaging demonstrated an occupancy in the right pelvis. A laparoscopic resection of the pelvic tumor was performed and pathologists identified it as an exophytic benign prostatic hyperplasia nodule. No significant recurrence was found at the 6-month follow-up.

Exophytic benign prostatic hyperplasia presenting with refractory retention: A rare entity

The transitional zone is the most common site of benign prostatic hyperplasia (BPH). Exophytic BPH is an exceedingly rare entity with only one case described in the English literature. We herein describe a case of exophytic BPH in a 48-year-old man presenting as a large pelvic mass with refractory retention managed successfully with robot assistance. To the best of our knowledge, this is the first case of exophytic benign prostatic enlargement managed by surgical excision.

Value of the hemorrhage exclusion sign on T1-weighted prostate MR images for the detection of prostate cancer

PURPOSE

To retrospectively determine the prevalence and positive predictive value (PPV) of the hemorrhage exclusion sign on T1-weighted magnetic resonance (MR) images in conjunction with findings on T2-weighted images in the detection of prostate cancer, with use of whole-mount step-section pathologic specimens from prostatectomy as the reference standard.

MATERIALS AND METHODS

The institutional review board approved this retrospective study, which was compliant with HIPAA, and the requirement to obtain informed consent was waived. Two hundred ninety-two patients with biopsy-proved prostate cancer underwent endorectal MR imaging followed by prostatectomy. The hemorrhage exclusion sign was defined as the presence of a well-defined area of low signal intensity surrounded by areas of high signal intensity on T1-weighted images. Two readers independently assessed the presence and extent of postbiopsy changes and the hemorrhage exclusion sign. The presence of a corresponding area of homogeneous low signal intensity on T2-weighted images was also recorded. The prevalence and PPV of the hemorrhage exclusion sign were calculated.

RESULTS

Readers 1 and 2 found postbiopsy changes in the peripheral zone in 184 (63%) and 189 (64.7%) of the 292 patients, respectively. In these patients, the hemorrhage exclusion sign was observed in 39 of 184 patients (21.2%) by reader 1 and 36 of 189 patients (19.0%) by reader 2. A corresponding area of homogeneous low signal intensity was seen on T2-weighted images in the same location as the hemorrhage exclusion sign in 23 of 39 patients (59%) by reader 1 and 19 of 36 patients (53%) by reader 2. The PPV of the hemorrhage exclusion sign alone was 56% (22 of 39 patients) for reader 1 and 50% (18 of 36 patients) for reader 2 but increased to 96% (22 of 23 patients) and 95% (18 of 19 patients) when the sign was identified in an area of homogeneous low signal intensity on T2-weighted images.

CONCLUSION

Postbiopsy change is a known pitfall in the interpretation of T2-weighted images. The authors have shown that a potential benefit of postbiopsy change is the presence of excluded hemorrhage, which, in conjunction with a corresponding area of homogeneous low signal intensity at T2-weighted imaging, is highly accurate for cancer identification.

The contribution of strain patterns in characterization of prostate peripheral zone lesions at transrectal ultrasonography

BACKGROUND

Elasticity is an important characteristic of tissue. During an elastography examination, various strain images of lesions are observed, and a suitable classification of strain patterns (SP) may provide vital diagnostic information about lesions. Numerous studies have shown that ultrasound elastography can improve the detection of prostate cancer, but the diagnostic value of SP classification has not yet been fully evaluated.

PURPOSE

To investigate the contribution of SP on the characterization of prostate peripheral zone lesions by transrectal real-time tissue elastography (TRTE) in combination with conventional transrectal ultrasonography (TRUS).

MATERIAL AND METHODS

One hundred and seventy-one patients with suspected prostate cancer underwent TRUS and TRTE examinations. The SPs of the suspicious lesions were classified into five scores by TRTE according to the degree and distribution of strain. All findings were confirmed by transrectal systematic 12-core biopsies and targeted biopsies for suspicious areas detecting by TRUS and/or TRTE.

RESULTS

One hundred and forty-eight of 171 patients had high-quality TRTE imaging and were included into the study. When a cut-off point of SP score III was used, the area under the receiver-operating characteristic curve (AUC) was, respectively, 0.75 (95% CI: 0.67-0.83), 0.85 (95% CI: 0.78-0.91) and 0.84 (95% CI: 0.77-0.91) for the diagnosis of prostate cancer by TRUS, TRTE and TRTE + TRUS. A linear tendency of SP and Gleason scores was observed in scores III-V. The detection rate of prostate cancer using TRTE-targeted biopsy (75.8%) was significantly higher than that of systematic 12-core biopsy plus TRUS-targeted biopsy (14.5%) (P = 0.00).

CONCLUSION

This study suggests the significant contribution of SP on characterization of prostate peripheral zone lesions and the improvement of TRTE-targeted biopsy on detection of prostate cancer.

Contrast-enhanced transrectal ultrasound for assessing vascularization of hypoechoic BPH nodules in the transition and peripheral zones: comparison with pathological examination

The purpose of this study was to investigate the vascularization of zonal location of hypoechoic benign prostatic hyperplasia (BPH) nodules and to evaluate the clinical value of contrast-enhanced transrectal ultrasound (CETRUS) for assessing vascularity of hypoechoic BPH nodules. Sixty-two patients with hypoechoic biopsy-proven BPH nodules in transition zone (TZ) (32 patients) or peripheral zone (PZ) (30 patients) of the prostate gland underwent CETRUS examination between January 2006 and September 2006. The enhancement characteristics of hypoechoic BPH nodules were observed and time to enhancement (AT), time to peak intensity (TTP) and peak intensity (PI) were measured with ACQ time-intensity curve analysis software. In addition, microvessel density (MVD) and vascular endothelial growth factor (VEGF) immunoreactivity were determined in the biopsy specimens. Microvessels were identified by immunohistochemical staining of endothelial cells for CD34. Findings were compared between hypoechoic BPH nodules located in PZ and TZ. The most common enhancement characteristic of hypoechoic BPH nodules in PZ was nonenhanced area inside (21/30), while most of hypoechoic BPH nodules in TZ appeared homogeneous enhancement (28/32). The average AT and TTP were significantly longer, the average PI was significantly lower in hypoechoic BPH nodules located in PZ than TZ (p < 0.01). The VEGF expression and MVD were significantly higher in hypoechoic BPH nodules located in TZ than PZ (p < 0.01). PI was found to be an important parameter strongly correlated with degree of vascularity of hypoechoic BPH nodules. Hypoechoic BPH nodules located in PZ and TZ showed significant difference in vascularization, which indirectly verified our finding that BPH nodule could occur in the peripheral zone. CETRUS could afford information on the vascularity of hypoechoic BPH nodules in a noninvasive manner and this could be used to improve selection of nodules for biopsy.

Does benign prostatic hyperplasia originate from the peripheral zone of the prostate? A preliminary study

OBJECTIVE

To compare the histological characteristics, cell proliferation, apoptosis and biological features in benign prostatic hyperplasia (BPH) in the peripheral (PZ) and transition zone (TZ) of the prostate.

PATIENTS AND METHODS

Tissue from BPH in TZ and PZ was obtained from 68 patients undergoing transrectal ultrasonography-guided biopsy and used for both morphometric analysis and immunohistochemical studies. The epithelial, stromal and luminal composition of the tissue was determined using a computer-assisted method for quantitative morphometric analysis. Apoptosis was detected as the apoptotic index (AI) using the TdT dUTP nick-end labelling assay. Cell proliferation was determined as the proliferation index (PI) using Ki-67 immunostaining. The expression of epidermal growth factor receptor (EGFR), transforming growth factor beta1 (TGFbeta1), androgen receptor (AR) and bcl-2 were assessed immunohistochemically.

RESULTS

There was no difference in the stroma/epithelium ratio between PZ and TZ hyperplastic nodules (P > 0.05). The mean AI in epithelium was almost identical to the corresponding PI. In stroma, no apoptotic cells were detectable. There was a significantly higher PI and AI in the glandular epithelial cells in PZ hyperplastic than in TZ hyperplastic nodules, but no difference in PI of the stromal cells between PZ and TZ hyperplastic nodules. There was significantly higher expression of TGFbeta1 and lower expression of EGFR and bcl-2 in PZ than TZ hyperplastic nodules (P < 0.05). There was no difference in AR expression between PZ and TZ hyperplastic nodules (P > 0.05).

CONCLUSIONS

These results indicate that some hyperplastic nodules in PZ might originate from the PZ, and the formation of these nodules might be modulated in a different way from that in the TZ.

Sildenafil citrate-aided radiotherapy for the treatment of Kaposi's sarcoma of the penis

We report a case of classical Kaposi's sarcoma involving multiple sites of the penis in a 62-year-old male who was treated with sildenafil citrate-aided electron beam therapy, resulting in complete resolution of the lesions.

Correlation between hypoechoic nodules on ultrasonography and benign hyperplasia in the prostatic outer gland

OBJECTIVE

The purpose of this investigation was to study the correlation between hypoechoic nodules detected on ultrasonography and benign hyperplasia in the prostatic outer gland (POG) diagnosed by transrectal ultrasonography (TRUS)-guided biopsies.

METHODS

The TRUS-guided biopsies were performed on 472 patients suspected of having prostate cancer. Specimens obtained by biopsies were independently assessed by pathologists at 3 hospitals.

RESULTS

The histologic results of 310 patients (65.68%) were benign. Focal hypoechoic nodules located in the POG were found in 240 patients (50.8%) on TRUS scans. Among them, in 22 patients (9.17% of the 240 patients with hypoechoic nodules), benign hyperplasia was found in focal hypoechoic nodules located in the POG. Focal nodules were seen as well circumscribed with an ovoid shape and smooth surface in 18 patients.

CONCLUSIONS

Benign hyperplasia may sometimes originate in the POG and may appear as a hypoechoic nodule, similar to the appearance of prostate cancer.