Supervised machine learning enables non-invasive lesion characterization in primary prostate cancer with [68Ga]Ga-PSMA-11 PET/MRI.

PURPOSE: Risk classification of primary prostate cancer in clinical routine is mainly based on prostate-specific antigen (PSA) levels, Gleason scores from biopsy samples, and tumor-nodes-metastasis (TNM) staging. This study aimed to investigate the diagnostic performance of positron emission tomography/magnetic resonance imaging (PET/MRI) in vivo models for predicting low-vs-high lesion risk (LH) as well as biochemical recurrence (BCR) and overall patient risk (OPR) with machine learning. METHODS: Fifty-two patients who underwent multi-parametric dual-tracer [18F]FMC and [68Ga]Ga-PSMA-11 PET/MRI as well as radical prostatectomy between 2014 and 2015 were included as part of a single-center pilot to a randomized prospective trial (NCT02659527). Radiomics in combination with ensemble machine learning was applied including the [68Ga]Ga-PSMA-11 PET, the apparent diffusion coefficient, and the transverse relaxation time-weighted MRI scans of each patient to establish a low-vs-high risk lesion prediction model (MLH). Furthermore, MBCR and MOPR predictive model schemes were built by combining MLH, PSA, and clinical stage values of patients. Performance evaluation of the established models was performed with 1000-fold Monte Carlo (MC) cross-validation. Results were additionally compared to conventional [68Ga]Ga-PSMA-11 standardized uptake value (SUV) analyses. RESULTS: The area under the receiver operator characteristic curve (AUC) of the MLH model (0.86) was higher than the AUC of the [68Ga]Ga-PSMA-11 SUVmax analysis (0.80). MC cross-validation revealed 89% and 91% accuracies with 0.90 and 0.94 AUCs for the MBCR and MOPR models respectively, while standard routine analysis based on PSA, biopsy Gleason score, and TNM staging resulted in 69% and 70% accuracies to predict BCR and OPR respectively. CONCLUSION: Our results demonstrate the potential to enhance risk classification in primary prostate cancer patients built on PET/MRI radiomics and machine learning without biopsy sampling.

Can the addition of clinical information improve the accuracy of PI-RADS version 2 for the diagnosis of clinically significant prostate cancer in positive MRI?

AIM: To report prostate cancer (PCa) prevalence in Prostate Imaging Reporting and Data System version 2 (PI-RADS v2) categories and investigate the potential to avoid unnecessary, magnetic resonance imaging (MRI)-guided in-bore biopsies by adding clinical and biochemical patient characteristics. MATERIALS AND METHODS: The present institutional review board-approved, prospective study on 137 consecutive men with 178 suspicious lesions on 3 T MRI was performed. Routine data collected for each patient included patient characteristics (age, prostate volume), clinical background information (prostate-specific antigen [PSA] levels, PSA density), and PI-RADS v2 scores assigned in a double-reading approach. RESULTS: Histopathological evaluation revealed a total of 93/178 PCa (52.2%). The mean age was 66.3 years and PSA density was 0.24 ng/ml2 (range, 0.04-0.89 ng/ml). Clinically significant PCa (csPCa, Gleason score >6) was confirmed in 50/93 (53.8%) lesions and was significantly associated with higher PI-RADS v2 scores (p=0.0044). On logistic regression analyses, age, PSA density, and PI-RADS v2 scores contributed independently to the diagnosis of csPCa (p=7.9×10-7, p=0.097, and p=0.024, respectively). The resulting area under the receiver operating characteristic curve (AUC) to predict csPCa was 0.76 for PI-RADS v2, 0.59 for age, and 0.67 for PSA density. The combined regression model yielded an AUC of 0.84 for the diagnosis of csPCa and was significantly superior to each single parameter (p≤0.0009, respectively). Unnecessary biopsies could have been avoided in 50% (64/128) while only 4% (2/50) of csPCa lesions would have been missed. CONCLUSIONS: Adding age and PSA density to PI-RADS v2 scores improves the diagnostic accuracy for csPCa. A combination of these variables with PI-RADS v2 can help to avoid unnecessary in-bore biopsies while still detecting the majority of csPCa.

68Ga-PSMA 11 ligand PET imaging in patients with biochemical recurrence after radical prostatectomy - diagnostic performance and impact on therapeutic decision-making.

OBJECTIVE: To evaluate the diagnostic performance of [68Ga]Ga-PSMAHBED-CC conjugate 11 positron emission tomography (PSMA-PET) in the early detection of metastases in patients with biochemical recurrence (BCR) after radical prostatectomy (RP) for clinically non-metastatic prostate cancer, to compare it to CT/MRI alone and to assess its impact on further therapeutic decisions. MATERIAL AND METHODS: We retrospectively assessed 117 consecutive hormone-naïve BCR patients who had 68Ga-PSMA 11 PET/CT (n = 46) or PET/MRI (n = 71) between May 2014 and January 2017. BCR was defined as two PSA rises above 0.2 ng/ml. Two dedicated uro-oncological imaging experts (radiology/nuclear medicine) reviewed separately all images. All results were presented in a blinded sequential fashion to a multidisciplinary tumorboard in order to assess the influence of PSMA-PET imaging on decision-making. RESULTS: The median time from RP to BCR was 36 months (IQR 16-72). Overall, 69 (59%) patients received postoperative radiotherapy. Median PSA level at the time of imaging was 1.04 ng/ml (IQR 0.58-1.87). PSMA-positive lesions were detected in 100 (85.5%) patients. Detection rates were 65% for a PSA value of 0.2 to <0.5 ng/ml, 85.7% for 0.5 to <1, 85.7% for 1 to <2 and 100% for ≥2. PSMA-positive lesions could be confirmed by either histology (16%), PSA decrease in metastasis-directed radiotherapy (45%) or additional information in diffusion-weighted imaging when PET/MRI was performed (18%) in 79% of patients. PSMA-PET detected lesions in 67 patients (57.3%) who had no suspicious correlates according to the RECIST 1.1 criteria on MRI or CT. PSMA-PET changed therapeutic decisions in 74.6% of these 67 patients (p < 0.001), with 86% of them being considered for metastases-directed therapies. CONCLUSIONS: We confirm the high performance of PSMA-PET imaging for the detection of disease recurrence sites in patients with BCR after RP, even at relatively low PSA levels. Moreover, it adds significant information to standard CT/MRI, changing treatment strategies in a significant number of patients.

P16INK4A immunohistochemistry for detection of human papilloma virus-associated penile squamous cell carcinoma is superior to in-situ hybridization.

We evaluated p16INK4A as a reliable option to detect human papilloma virus (HPV) DNA in penile tumor specimens. Formalin-fixed paraffin embedded samples of 26 patients with penile cancer and another 18 cases with non-tumorigenic lesions were stained by three different widely used commercially available chromogenic in-situ hybridization assays high-risk HPV CISH Y1443 (Genpoint, DAKO), pan HPV CISH Y1404 (Genpoint, DAKO), INFORM HPV III (Ventana, Tucson, Arizona) and p16INK4A immunohistochemistry, then compared to the known gold standard polymerase chain reaction detecting HPV 16, 18, 31, and 33. Immunoreactivity for p16INK4A was evaluated by using a 4-tiered (0, 1, 2, and 3) pattern based system. 19 cases were positive for p16INK4A, 13 of which showed a continuous transepithelial staining (pattern 3). Pan HPV ISH showed positivity in 9 cases, high-risk HPV ISH in 7 cases and INFORM HPVIII ISH in 7 cases. p16INK4A IHC pattern 3 versus pattern 0, 1 and 2 exhibited a specificity and positive predictive value of 100 percent, with a sensitivity and negative predictive value of 72 and 62 percent, respectively, which was much better than all HPV in-situ hybridization methods referred to polymerase chain reaction. p16INK4A seems to be a superior marker for the detection of HPV-associated penile squamous cell carcinoma compared to CISH tests, but is not recommend for the detection of non-tumorigenic lesions, where PCR should be used for the initial assessment.

CD98hc (SLC3A2), a novel marker in renal cell cancer.

BACKGROUND: In a variety of malignant diseases, molecular targeting represents a therapeutic option, whereby, when compared with chemotherapy, fewer side effects are thought to be expected. Especially in renal cell cancer (RCC), tyrosine kinase-inhibitors have been established as useful and highly effective therapy. However, tyrosine kinase-inhibitors currently approved for RCC treatment lack single molecule specificity and bear a variety of side effects of the gastro-intestinal tract, skin, heart and haematopoietic system. Therefore, the identification of novel cell surface markers is sought, which might lead to novel diagnostic and therapeutic strategies in cancer. MATERIAL AND METHODS: Paraffin-embedded RCCs from a well characterized tissue bank were immunohistochemically quantified for embryonic transmembrane antigen CD98hc (SLC3A2) expression and semi-quantitative analyses were correlated with subtype or grade of differentiation. RESULTS: We found increased CD98hc expression in different types of malign RCCs, among them clear cell (cc)RCC, papillary (p)RCC and chromophobe (ch)RCC, but lack of expression in the benign renal oncocytoma. Thereby, the extent of CD98hc expression directly complies with grade of malignancy. Furthermore, the more malignant type II pRCC significantly higher expressed CD98hc than the less malignant and more differentiated type I pRCC (type II 83.34%, type I 4.76% CD98hc positive, P < 0.00001; n = 51). The established marker for type I pRCC, Cytokreatin 7, showed 95.24% expression in type I and 26.67% expression in type II pRCC (P < 0.00001, n = 51). CONCLUSIONS: From these data, we conclude that CD98hc is expressed in RCCs, whereby the extent of expression is likely to correlate directly with grade of malignancy. In pRCCs, CD98hc might represent a novel and reliable marker for type II pRCC.

[Diagnostic of prostate cancer: conventional and molecular or cell biological methods]. / Diagnostik des Prostatakarzinoms : Konventionelle und molekular- bzw. zellbiologische Methoden.

At present the diagnosis of prostate cancer is carried out by transrectally obtained biopsy samples. The histological findings, the value for prostate-specific antigen (PSA) in the serum, and the clinical stage are the objective criteria for all subsequent therapy decisions. In over 95% of cases an acinar "usual" form of prostate cancer is diagnosed but can be very different in characteristics and differentiation. In order to correctly assess prostate cancer and to be able to select the best possible therapeutic measures resulting from the diagnosis, all information obtained from the biopsy must be used to a maximum. The demands on the optimal biopsy findings have considerably expanded in recent years. It must be able to obtain all additional biological, molecular and genetic findings from the biopsy material.

Basic fibroblast growth factor augments podocyte injury and induces glomerulosclerosis in rats with experimental membranous nephropathy.

Podocyte injury is believed to contribute to glomerulosclerosis in membranous nephropathy. To identify the factors involved, we investigated the effects of basic fibroblast growth factor (bFGF), a cytokine produced by podocytes, on rats with membranous nephropathy (passive Heymann nephritis [PHN]). All rats received a daily i.v. bolus of 10 microg bFGF or vehicle from days 3-8 after PHN induction. In proteinuric PHN rats on day 8, bFGF injections further increased proteinuria. Podocytes of bFGF-injected PHN rats showed dramatic increases in mitoses, pseudocyst formation, foot process retraction, focal detachment from the glomerular basement membrane, and desmin expression. bFGF injections in PHN rats did not alter antibody or complement deposition or glomerular leukocyte influx. bFGF-injected PHN rats developed increased glomerulosclerosis when compared with control PHN rats. Also, bFGF induced proteinuria and podocyte damage in rats injected with 10% of the regular PHN-serum dose. None of these changes occurred in bFGF-injected normal rats, complement-depleted PHN rats or rats injected with 5% of the regular PHN serum dose. These divergent bFGF effects were explained in part by upregulated glomerular bFGF receptor expression, induced by PHN serum. Thus, bFGF can augment podocyte damage, resulting in increased glomerular protein permeability and accelerated glomerulosclerosis. This bFGF action is confined to previously injured podocytes. Release of bFGF from glomerular sources (including podocytes themselves) during injury may represent an important mechanism by which podocyte damage is enhanced or becomes self sustained.

Pathogenic antibodies inhibit the binding of apolipoproteins to megalin/gp330 in passive Heymann nephritis.

Megalin/gp330 is an endocytic receptor that internalizes multiple ligands including apolipoproteins E (apo E) and B100 (apo B). Megalin is the main antigenic target in passive Heymann nephritis (pHN), where it binds circulating autoantibodies leading to the formation of subepithelial immune deposits (ID)-the hallmark of pHN. Apo E and apo B were found recently to accumulate within these IDs, and evidence was provided that their lipids may undergo peroxidation, causing glomerular basement membrane damage and proteinuria. Here we investigated if ID-forming antimegalin IgG can inhibit the binding and internalization of apo E-betaVLDL (very low density lipoprotein) by megalin, and lead to their accumulation within IDs. By immunoelectron microscopy, apo E and apo B were detected in clathrin-coated pits and multivesicular bodies of podocytes in control rats, suggesting that the uptake of lipoproteins is a constitutive function of the glomerular epithelium. When pHN was induced by intravenous injection of antimegalin IgG, apo E and apo B were found within IDs by immunofluorescence and immunoelectron microscopy. Bound antibodies eluted from glomeruli of rats with pHN were found to inhibit the binding and internalization of apo E-enriched betaVLDL by megalin. These results indicate that pHN-inducing antimegalin IgG is capable of interfering with the uptake of lipoproteins by megalin in vivo during the formation of IDs.

Molecular-cytogenetic characterisation of sex cord-stromal tumours: CGH analysis in sertoli cell tumours of the testis.

Sertoli cell tumours (SCT) are rare and poorly explored neoplasias, and the genetic features of these uncommon tumours are largely unknown. Data about chromosomal aberrations in human SCT of the testis are very rare. We present in this paper the first molecular-cytogenetic study of SCT of the testis. DNA was isolated from paraffin-embedded tumour material from 11 patients with unilateral SCT. We used comparative genomic hybridisation to investigate changes in DNA copy number. The detected DNA imbalances showed variation from case to case, indicating a high genetic heterogeneity. Chromosomal aberrations were detected in 9 of the 11 tumours evaluated, with 13 losses versus 14 gains. The most frequent aberrations detected were gain of chromosome X (5 of 11 cases) followed by losses of entire or part of chromosomes 2 and 19 in three cases. This study suggests a high variability in histomorphological and genetic patterns. Only gain of the entire chromosome X seems to be a frequent aberration in these tumours. Further studies of these tumour types are necessary to clarify the significance of chromosomal alterations in carcinogenesis of SCT.

Leydig cell tumors of the testis: a molecular-cytogenetic study based on a large series of patients.

The genetic features of the uncommon Leydig cell tumors (LCT) are largely unknown. Consequently, it is of great importance to elucidate the pathogenesis of testicular germ cell tumors by cytogenetic and molecular biological investigations. The purpose of the present study was the examination of cytogenetic features of these tumors in a large series of LCT. It comprised formalin-fixed, paraffin-embedded tissue samples from 25 LCT to analyze the chromosomal constitution using comparative genomic hybridization (CGH). In most of the studied cases, the aberrant cell population was additionally defined by interphase fluorescence in situ hybridization (I-FISH). Our molecular-cytogenetic study indicates chromosomal imbalances in the majority of our cases (21/25, 84%). The most frequent findings were gain of chromosome X, 19 or 19p and loss on chromosome 8 and 16.

Effect of high-intensity focused ultrasound on human prostate cancer in vivo.

Transrectal high-intensity focused ultrasound (HIFU) was recently established as a highly effective means of inducing contact and irradiation-free intraprostatic coagulative necrosis. This technique, therefore, appears potentially useful for treating localized prostate cancer (PC). To evaluate this issue, a total of 29 human prostates with localized cancer was subjected to HIFU treatment in vivo before radical retropubic prostatectomy. HIFU therapy was performed with the use of HIFU transducers with focal lengths of 3.0 cm (n = 3), 3.5 cm (n = 19), and 4.0 cm (n = 7), and the site intensity was varied from 1260 to 2000 W/cm2. The extent of intraprostatic necrosis was determined by planimetrical analysis of whole mount prostatic sections. Transrectal HIFU consistently induced sharply delineated intraprostatic coagulative necrosis within the target area, whereas alterations of perioprostatic structures were never observed. The cross-sectional area of necrosis increased from 1.1 +/- 0.7 cm2 (SD; n = 3; 3.0-cm focal length; 1428 W/cm2) to 1.2 +/- 0.7 cm2 (n = 2; 3.5-cm focal length; 1428 W/cm2), 1.8 +/- 0.17 cm2 (n = 8; 3.5-cm focal length; 1680 W/cm2), 2.8 +/- 0.32 cm2 (n = 9; 3.5-cm focal length; 2000 W/cm2) and 3.8 +/- 0.4 cm2 (n = 7; 4.0 cm focal length; 1260 W/cm2). HIFU beam transmission and the therapeutic effect were comparable in benign and malignant prostatic tissue. Interstitial thermometry (n = 6) revealed maximum intraprostatic temperatures in the focal zone up to 98.6 degrees C. Outside the focal zone and on the rectal wall, no significant temperature rises were noted. Subsequently, HIFU was applied to unilateral histologically proven T2a/T2b PC (n = 10) in an attempt to destroy all cancer before radical retropubic prostatectomy. PC was always correctly targeted. In 7 individuals, PC was partially (mean, 53%; range, 38-77%) destroyed; in the remaining 3 cases the entire tumor was ablated. Although these histological data permit no definitive conclusion on the clinical efficacy of this approach, transrectal HIFU seems to be an attractive novel minimally invasive treatment option for localized PC.

Involvement of cytochrome b5 and a cyanide-sensitive monooxygenase in the 4-demethylation of 4,4-dimethylzymosterol by yeast microsomes.

According to Ohba et al. (Ohba, M., Sato, R., Yoshida, Y., Nishino, T. and Katsuki, H. (1978) Biochem. Biophys. Res. Commun. 85, 21-27), yeast microsomes catalyze the removal of three methyl groups attached to the C-4 and C-14 positions of [1,7,15,22,26,30-14C]lanosterol (4,4,14 alpha-trimethyl-5 alpha-cholesta-8,24-dien-3 beta-ol) in the presence of NADPH, NAD+ and molecular oxygen, concomitant with the liberation of 14CO2 derived from C-30 (one of the two methyl groups at the C-4 position). In this process the methyl group at the C-14 position is first removed in a cyanide-insensitive reaction and then the two methyl groups at the C-4 position are removed by a cyanide-sensitive enzyme system. In this study it was found that the 14CO2 formation from the 14C-labeled lanosterol was inhibited by antibodies to yeast cytochrome b5 and by palmitoyl-CoA, a substrate of the cytochrome b5-containing fatty acyl-CoA desaturase system of yeast microsomes. However, neither the antibodies nor palmitoyl-CoA inhibited the conversion of lanosterol to 4,4-dimethyl zymosterol (4,4-dimethyl-5 alpha-cholesta-8,24-dien-3 beta-ol). It is concluded that cytochrome b5 and a cyanide-sensitive enzyme are involved in the 4-demethylation of 4,4-dimethylzymosterol, but not the 14 alpha-demethylation of lanosterol, by yeast microsomes. It is suggested that a cyanide-sensitive enzyme acts as the terminal 4-demethylase and cytochrome b5 transfers reducing equivalents from NADPH to the terminal enzyme, as in the case of fatty acyl-CoA desaturation. The cyanide sensitivity of the 4-demethylation was, however, much greater than that of the desaturation.

mdm2 expression as a prognostic indicator in clear cell renal cell carcinoma: comparison with p53 overexpression and clinicopathological parameters.

The present study was designed to analyze the expression of p53 and mdm2 in clear cell renal cell carcinoma with special emphasis on their association with tumor grade and clinical outcome. In particular, the value of individual protein overexpression as well as combined p53/mdm2 positivity was evaluated because both proteins are functionally connected, and their expression is controlled by an autoregulatory feedback loop. A cohort of 97 clear cell renal cell carcinomas was analyzed. The overexpression of mdm2 and p53 proteins was investigated on paraffin-embedded material by using monoclonal antibodies. Eighteen tumors showed mdm2 positivity, whereas 35 of the tumors overexpressed p53. Whereas p53 and mdm2 positivity correlated significantly (P = 0.00004), no correlation could be found between mdm2 protein overexpression and tumor stage, lymph node involvement, and presence of distant metastases. mdm2 positivity was found significantly more frequently in tumors of higher grade. In univariate analysis, there was a statistically significant correlation between p53 and mdm2 overexpression in the same tumor and poor survival (P = 0.00179). Multivariate analysis revealed that coincident mdm2/p53 overexpression, the presence of distant metastases, and tumor grade were independent predictors for tumor progression. Our results indicate that mdm2/p53 co-overexpression, nuclear grade, and preoperative presence of distant metastasis are independent predictors for poor survival.

Common IgE-epitopes of recombinant Phl p I, the major timothy grass pollen allergen and natural group I grass pollen isoallergens.

Grass pollen allergens are potent elicitors of Type I allergy. More than 95% of grass pollen allergic patients display IgE-cross-reactivity to group I grass pollen allergens of different grass species. A cDNA coding for the major timothy grass pollen allergen, Phl p I, was isolated previously. To investigate the presence of common IgE-epitopes among naturally occurring group I grass pollen isoallergens, Phl p I was expressed in Escherichia coli and used for IgE-absorption experiments. Recombinant Phl p I was able to inhibit IgE-binding to most of group I isoallergens from seven grass species as identified by two dimensional electrophoresis. When tested in competitive ELISA experiments, recombinant Phl p I bound a high percentage of grass pollen specific IgE. The results indicate that recombinant Phl p I shares many of the IgE-epitopes with natural group I grass pollen allergens and hence may represent a useful tool for specific diagnosis and therapy of grass pollen allergy.

High incidence of nephrogenic adenoma of the bladder after renal transplantation.

BACKGROUND: Tumors of the bladder termed nephrogenic adenomas in kidney allograft recipients are believed to develop as urothelial metaplastic proliferations in response to mechanical trauma, chemical noxae, irradiation, and bacterial or viral pathogens. We report on the incidence of nephrogenic adenoma of the bladder in patients who received renal transplants during a period of 7 years and 3 months at the University Hospital of Vienna. METHODS: Diagnosis was obtained by cystoscopy and histological analysis. Nephrogenic adenoma was treated by transurethral electroresection and administration of antibiotics in case of urinary tract infections. Follow-up consisted of cytological controls of urine and bladder irrigation fluid as well as of cystoscopy every 3 months. RESULTS: In 7 of 1328 renal allograft recipients, nephrogenic adenoma could be detected after 7 to 60 months following renal transplantation. In five patients, recurrence was detected 9 to 23 months after diagnosis of the initial lesion. No evidence of malignant degeneration was observed in any patient. Nephrogenic adenoma was not related to immunosuppressive therapy, cytomegalovirus disease, or gancyclovir therapy. CONCLUSIONS: We suggest that after successful transurethral electroresection of nephrogenic adenomas, cytological controls are adequate every 3 months. Only in renal transplant patients with recurrence of voiding disturbances, macrohematuria, or urinary tract infection are cystoscopy and biopsy indicated in the routine follow-up regimen.

Proliferating cell nuclear antigen and MIB-1. An alternative to classic prognostic indicators in renal cell carcinomas?

Tumor progression and clinical outcome for patients with renal cell carcinomas (RCCs) cannot be predicted based solely on tumor staging and grading. In a retrospective study we have therefore attempted to analyze the capacity of proliferation markers to provide additional prognostic information. One hundred seven cases of RCC were investigated by immunohistochemical analysis using two different monoclonal antibodies: PC10, which recognizes a proliferating cell nuclear antigen (PCNA), and MIB-1, which identifies the Ki-67 antigen in formalin-fixed, paraffin-embedded material. PCNA frequency ranged from 0% to 71% (mean, 17%), and MIB-1 expression, from 0% to 43% (mean, 11%). PCNA scores correlated significantly with MIB-1 immunoreactivity. PCNA and MIB-1 immunoreactivity showed a significant correlation with tumor grade. A strong correlation was also observed for T-component of stage and MIB-1 scores, but no correlation was found between PCNA and T-component of stage. In univariate analysis, PCNA immunoreactivity and MIB-1 scores were significant predictors of survival. Multivariate analysis, using a Cox proportional hazard model, showed PCNA index, N-component of stage, and tumor grade to be independent predictors of tumor progression, which is not the case for MIB-1 index.

Capillary haemangioma of the testis.

A case of testicular capillary haemangioma is reported and the importance of intraoperative examination of this very rare lesion emphasised. Capillary haemangioma of the testis can be similar to malignant testicular tumours on clinical presentation, as well as on ultrasonography and magnetic resonance imaging, and therefore should be included in the intraoperative differential diagnosis. Because of the benign nature of this lesion, conservative surgical treatment by means of tumour enucleation with preservation of the testis is possible, if intraoperative examination of frozen sections of representative tissue can be performed.

Incidence of testicular microlithiasis.

In adults polytopic intratubular calcifications of the testes are rare. Known as testicular microlithiasis, they manifest themselves in a characteristic echo pattern on sonography with high-frequency transducers (5 to 10 MHz). This consists of multiple echogenic specks in an otherwise normal testicular parenchyma. In a retrospective analysis of 1,710 testicular sonograms of adults, bilateral intratesticular microliths were found in 11 cases (0.6%). In 5 of them, the microliths were associated with a testicular tumor. One patient with a tumor in the contralateral testis had undergone radiotherapy and another one presented with hypogonadism. Four patients with noncontributory histories presented with varicocele or epididymal cyst. Sonographic findings were confirmed histologically in 6 patients. Multiple intratubular calcifications were found in all of them. The pathogenesis of testicular microliths is still poorly understood. Their clinical relevance is unclear, but their incidence in adults appears to be higher than reported in the literature.

Transperineal radiofrequency interstitial tumor ablation of the prostate: correlation of magnetic resonance imaging with histopathologic examination.

OBJECTIVES: Radiofrequency (RF) energy has recently been employed to destroy human tissue in vivo. The purpose of this study was to investigate the safety of this approach in localized carcinoma of the prostate (CaP) and specifically, the predictability of lesions obtained with radiofrequency interstitial tumor ablation (RITA). METHODS: Using RITA, a total of 21 lesions were induced in 10 patients with localized CaP (mean age 70.4 years). RF was delivered transperineally under transrectal ultrasound (TRUS) guidance. All patients underwent endorectal magnetic resonance imaging (MRI) before and after treatment. Radical prostatectomy was performed in all patients 1 to 7 days after RITA. Three of the patients were treated with local anesthesia only. The predictability of the thermal lesion was assessed by correlating the findings of intraoperative TRUS, pre- and post-RITA endorectal MRI, and the histologic examination of the specimen. RESULTS: Postoperatively, patients were catheterized for an average of 1.8 days (1 to 3 days). Lesions of 2 x 2 x 2 cm were targeted. Average lesion diameters obtained on MRI were 2.08 +/- 0.23 x 2.09 +/- 0.36 x 2.28 +/- 0.21 cm. Average lesion diameters defined by coagulative necrosis at histologic examination were 2.20 +/- 0.23 x 2.10 +/- 0.31 x 2.38 +/- 0.14 cm. There were no statistically significant differences (P = 0.377) between average lesion volume on MRI (5.37 +/- 1.83 cm3) and average lesion volume at histology (5.86 +/- 1.63 cm3). No complications or adverse events were noted. CONCLUSIONS: In this Phase I study, RITA was shown to be safe and feasible, and to result in lesions that were predictable in size and location. MRI accurately visualized and verified the area of coagulative necrosis as documented at histology. The procedure is technically simple and can even be performed under local anesthesia.

Gastric perforation of a left lobe amoebic liver abscess.

Liver abscess is the most common extra-intestinal manifestation of invasive amoebiasis. Perforation of the abscess is a potential life-threatening complication. We report a case where perforation into the stomach was successfully managed conservatively. The initial diagnosis in this case was made by gastroscopy and biopsy. To our knowledge, only five cases of gastric perforation of an amoebic liver abscess have been reported in the English literature. In none of these cases was the diagnosis established by histology of gastric biopsy specimens.