Small cell variant of chromophobe renal cell carcinoma: Clinicopathologic, and molecular-genetic analysis of 10 cases

The morphologic diversity of chromophobe renal cell carcinoma (ChRCC) is well-known. Aside from typical morphology, pigmented adenomatoid, multicystic, and papillary patterns have been described. Ten cases of CHRCC composed of small-cell population in various percentages were analyzed, using morphologic parameters, immunohistochemistry, and next-generation sequencing testing. Patients were five males and five females, with age ranging from 40 to 78 years. The size of tumors ranged from 2.2 cm to 11 cm (mean 5.17 cm). Small-cell component comprised 10 to 80% of the tumor volume, while the remaining was formed by cells with classic ChRCC morphology. The immunohistochemical profile of the small-cell component was consistent with typical ChRCC immunophenotype, with CD117 and CK7 positivity. Neuroendocrine markers were negative. Mutations of 13 genes were found: DCIER1, FGFR3, JAK3, SUFO, FAM46C, FANCG, MET, PLCG2, APC, POLE, EPICAM, MUTYH, and AR. However, only the PLCG2 mutation is considered pathogenic. The small-cell variant of ChRCC further highlights and expands on existing morphologic heterogeneity spectrum. Recognition of small-cell variant of CHRCC is not problematic in tumors, where the “classic” CHRCC component is present. However, in limited material (i.e., core biopsy), this may present a diagnostic challenge. Based on the limited follow-up data available, it appears that the small-cell tumor component had no impact on prognosis, since there was no aggressive behavior documented. Awareness of this unusual pattern and applying additional sections to find classic morphology of ChRCC, as well as excluding neuroendocrine nature by immunohistochemistry, may help resolve difficult cases.

The Ability of Prostate Health Index (PHI) to Predict Gleason Score in Patients With Prostate Cancer and Discriminate Patients Between Gleason Score 6 and Gleason Score Higher Than 6-A Study on 320 Patients After Radical Prostatectomy

Aim:

The purpose of this study was to investigate the Prostate Health Index as a marker for tumor aggressiveness in prostate biopsy and the optimization of indication for treatment options.

Methods:

Our cohort consisted of 320 patients indicated for radical prostatectomy with preoperative measurements of total prostate-specific antigen, free prostate-specific antigen, [-2]proPSA, calculated %freePSA, and Prostate Health Index. The Gleason score was determined during biopsy and after radical prostatectomy. Using the Gleason score, we divided the group of patients into the 2 subgroups: Gleason score ≤6 and Gleason score >6. This division was performed according to the biopsy Gleason score and according to the postoperative Gleason score. We compared total prostate-specific antigen, [-2]proPSA, %freePSA, and Prostate Health Index in the subgroups Gleason score ≤6 and Gleason score >6 after biopsy and the definitive score.

Results:

On evaluation of the subgroups created by Gleason score ≤6 and Gleason score >6, we observed agreement between biopsy Gleason score and definitive Gleason score in only 45.3% of cases. Of the calculated biopsy, Gleason score ≤6 and Gleason score >6 subgroups, [-2]proPSA, and Prostate Health Index (P = .0003 and P = .0005) were statistically significant. Of the definitive Gleason score ≤6 and Gleason score >6 subgroups, Prostate Health Index, [-2]proPSA, %freePSA, and PSA (P < .0001, P < .0001, P = .0003, and P = .0043) were statistically significant. The best area under the curve value (0.7496) was achieved by Prostate Health Index when the subgroups were established according to the postoperative Gleason score.

Conclusion:

Prostate Health Index is the best of the tested markers for the categorization of Gleason score 6 tumors and for facilitating the management of patients with prostate cancer. Prostate Health Index can be a helpful marker for indication of active surveillance or radical prostatectomy. Prostate health index can also simplify the decision of whether to perform nerve-sparing radical prostatectomy.

Stability of total prostate-specific antigen and free prostate-specific antigen after 10 years’ storage

Introduction:

PSA is a serine protease composed of 240 amino acids in a single polypeptide chain and is a routine parameter in prostate cancer diagnostics. The aim of our study was to test the long-term stability of tPSA and fPSA after 10 years’ storage at −80°C.

Materials and methods:

We analyzed two aliquots from 55 serum samples. The first was assayed in routine testing at the time of establishing the diagnosis. The second was thawed for further testing after approximately 10 years’ storage at −80°C. The mean of storage time was 10.41 years (min–max: 9.35–11.40 years). We compared the results of tPSA and fPSA. We calculated the fPSA/tPSA ratio and compared the results of clinical evaluation. Serum tPSA and fPSA levels were assayed using chemiluminescent kits Access Hybritech PSA and free PSA. All measurements were performed using the instrument UniCel® DxI 800.

Results:

tPSA decreased 3.59% on average with a correlation r=0.9213, and fPSA increased at an average of 2.41% with a correlation r=0.9338. The fPSA/tPSA ratio increased 0.80% on average with a correlation r=0.9174. On clinical evaluation, five samples had fallen to a less malignant category and three samples had risen to a higher malignant category compared with the original results.

Conclusion:

The stability of tPSA and fPSA levels in serum is sufficient after 10 years’ storage at −80°C. Calculation of the fPSA/tPSA ratio is not recommended due to the change in the category of malignancy of 15% of the samples.

PHI in the Early Detection of Prostate Cancer

AIM

To evaluate changes in the serum levels of prostate specific antigen (PSA), %free PSA and -2proPSA biomarkers, and prostate health index (PHI) in the diagnostic algorithm of early prostate cancer.

PATIENTS AND METHODS

The Immunoanalytical Laboratory of the University Hospital in Pilsen examined sera from 263 patients being treated at the Hospital's Urology Department with suspected prostate cancer who had undergone biopsies and were divided into a benign and malignant group. The monitored biomarkers were measured using chemiluminescence. All statistical analyses were calculated using the SAS software.

RESULTS

We found statistically significantly increased levels of -2proPSA, PHI and PSA and decreased levels of %freePSA in patients diagnosed with prostate cancer by prostate biopsy vs. patients with benign prostatic hypertrophy (median values: -2proPSA: 16 vs. 21 ng/l, PHI: 35 vs. 62, total PSA: 7.2 vs. 7.7 μg/l and %free PSA: 16.7 vs. 11.7%). Receiver operating characteristic curves showed the best performance for PHI compared to other markers.

CONCLUSION

The assessment of -2proPSA and the calculation of PHI appear to be of great benefit for a more accurate differential diagnosis of benign hyperplasia and prostate cancer.

Choriogonadotropin positive seminoma-a clinicopathological and molecular genetic study of 15 cases

The presence of human chorionic gonadotropin (hCG) positive syncytiotrophoblastic cells (STC) in classic seminoma (CS) is well documented. CS with extensive hCG positive, non-syncytiotrophoblastic tumour cells (without STC) is exceptionally rare. In this study, we present 15 such cases. 168 CSs were retrieved from the Plzen Tumor registry. Cases of mixed germ cell tumors (with CS) and CSs with typical STC were excluded. Cases with completely embedded tumor mass were selected for further study and immunohistochemically examined with anti-hCG. Positive cases were further analyzed by reverse transcriptase polymerase chain reaction. Two groups of hCG-positive CSs were identified. Group 1 comprised 10 patients with a mean patient age of 37.7 years and mean tumor size of 4.96 cm. Eight cases were pT1 (TMN 2009) and 2 cases pT3a. Blood levels of hCG were elevated in 6 of the 10 patients preoperatively. In 2 patients the blood level of hCG was not tested. Mean follow-up period was 6.1 years. No metastatic behavior was noted. All tumors were extensively immunoreactive for hCG in more than 60% of tumor cells. The expression of hCG beta subunit (CGB)-mRNA in tumor tissue was documented. Group 2: Comprised 5 patients with a mean age was 34 years. Mean tumor size was 4.7 cm. Four cases were stage pT1 and 1 case was pT2. The mean follow-up period was 3.1 years. No metastatic behavior was noted. Preoperative blood levels of hCG were elevated in 1/5 of the patient. Strong hCG positivity was limited to scattered single tumor cells distributed throughout the entire tumor. Only weak expression of CGB mRNA was detected. We can conclude that immunohistochemical detection of expression of hCG in CS is not limited to syncytiotrophoblastic cells. In this study, we report two immunohistochemical patterns of hCG expression in classic seminomas: diffuse hCG staining in the majority of tumor cells and scattered hCG-positive cells within the tumor.