Nonneoplastic lesions of the prostate and bladder

Deep UV Microscopy Identifies Prostatic Basal Cells: An Important Biomarker for Prostate Cancer Diagnostics

Objective and Impact Statement. Identifying benign mimics of prostatic adenocarcinoma remains a significant diagnostic challenge. In this work, we developed an approach based on label-free, high-resolution molecular imaging with multispectral deep ultraviolet (UV) microscopy which identifies important prostate tissue components, including basal cells. This work has significant implications towards improving the pathologic assessment and diagnosis of prostate cancer. Introduction. One of the most important indicators of prostate cancer is the absence of basal cells in glands and ducts. However, identifying basal cells using hematoxylin and eosin (H&E) stains, which is the standard of care, can be difficult in a subset of cases. In such situations, pathologists often resort to immunohistochemical (IHC) stains for a definitive diagnosis. However, IHC is expensive and time-consuming and requires more tissue sections which may not be available. In addition, IHC is subject to false-negative or false-positive stains which can potentially lead to an incorrect diagnosis. Methods. We leverage the rich molecular information of label-free multispectral deep UV microscopy to uniquely identify basal cells, luminal cells, and inflammatory cells. The method applies an unsupervised geometrical representation of principal component analysis to separate the various components of prostate tissue leading to multiple image representations of the molecular information. Results. Our results show that this method accurately and efficiently identifies benign and malignant glands with high fidelity, free of any staining procedures, based on the presence or absence of basal cells. We further use the molecular information to directly generate a high-resolution virtual IHC stain that clearly identifies basal cells, even in cases where IHC stains fail. Conclusion. Our simple, low-cost, and label-free deep UV method has the potential to improve and facilitate prostate cancer diagnosis by enabling robust identification of basal cells and other important prostate tissue components.

Gene Expression-Based Functional Differences between the Bladder Body and Trigonal Urothelium in Adolescent Female Patients with Micturition Dysfunction

The aim of this study is to determine the molecular differences between the urothelial transcriptomes of the bladder body and trigone. The transcriptomes of the bladder body and trigonal epithelia were analyzed by massive sequencing of total epithelial RNA. The profiles of urothelial and urinal microbiomes were assessed by amplicon sequencing of bacterial 16S rRNA genes in 17 adolescent females with pain and micturition dysfunction and control female subjects. The RNA sequencing identified 10,261 differentially expressed genes (DEGs) in the urothelia of the bladder body and trigone, with the top 1000 DEGs at these locations annotated to 36 and 77 of the Reactome-related pathways in the bladder body and trigone, respectively. These pathways represented 11 categories enriched in the bladder body urothelium, including extracellular matrix organization, the neuronal system, and 15 categories enriched in the trigonal epithelium, including RHO GTPase effectors, cornified envelope formation, and neutrophil degranulation. Five bacterial taxa in urine differed significantly in patients and healthy adolescent controls. The evaluation of their transcriptomes indicated that the bladder body and trigonal urothelia were functionally different tissues. The molecular differences between the body and trigonal urothelia responsible for clinical symptoms in adolescents with bladder pain syndrome/interstitial cystitis remain unclear.

Primary signet-ring cell carcinoma of the urinary bladder

Primary signet-ring cell carcinoma of the urinary bladder is a rare tumor. The overall incidence is approximately 0.12-0.6% of all urinary bladder malignancies. The majority of the patients present in an advanced stage with a uniformly grim prognosis. As signet-ring cell carcinomas are more common in the gastrointestinal tract, a possibility of metastasis needs to be considered. Here we report, a 42-year-old patient who presented with hematuria and was diagnosed with a urinary bladder tumor. The patient was managed with partial cystectomy and pelvic lymph node dissection. The histopathological examination confirmed primary signet-ring cell carcinoma of the urinary bladder.

Benign mimics of prostate cancer

The histopathological diagnosis of prostatic adenocarcinoma is challenged by the existence of numerous benign mimics. Most of these lesions have no clinical significance and many do not need to be reported. Their clinical relevance lies in the risk that they are misinterpreted as cancer. This review presents the histopathological features of benign mimics and discusses their distinction from cancer. The lesions that are most often misdiagnosed as cancer are atrophy and its variants, including simple atrophy, partial atrophy and post-atrophic hyperplasia. Benign proliferations are a group of lesions with crowded small glands with no or little nuclear atypia. The most problematic entity of this group is adenosis, which may have a more alarming architecture than some cancers. A diagnostic problem with atrophy and several of the benign proliferations is that the glands often have a discontinuous or absent basal cell layer. Hyperplastic and metaplastic lesions include basal cell hyperplasia. Basal cell hyperplasia may especially mimic prostate cancer with its small dark glands, variable nuclear atypia and a pseudoinfiltrative pattern, which may be present. The anatomical structure that most often causes diagnostic problems is the seminal vesicle. The mucosa of the seminal vesicle contains small acini, often with very pronounced nuclear atypia that may be misinterpreted as cancer. Pathologists need to be familiar with these mimics, as a false positive diagnosis of prostate cancer may lead to unnecessary radical treatment.

Incidence of adenocarcinoma bladder in patients with cystitis cystica et glandularis: A retrospective study

Introduction:

Cystitis cystica et glandularis (CCG) is a hyper proliferative condition, likely representing a local immune response to chronic inflammatory stimulus. It has been hypothesized as a potential precursor of adenocarcinoma; however, a definite association has not been demonstrated. We aimed to determine whether CCG is a precursor to malignancy and to study the correlation of its two histological variants: the typical and the intestinal metaplasia (IM) type CCG.

Materials and Methods:

In this retrospective study, all the cases of CCG diagnosed and treated between January 2012 and December 2019 were analyzed. All the cases were followed up cystoscopically and biopsies were taken if the lesion persisted. The development of adenocarcinoma during the follow-up was noted. The patients were divided into two groups based on the histological subtype, i.e., the typical type and the IM type, and the two groups were also compared in terms of presentation, cystoscopic appearance, and development of adenocarcinoma.

Results:

A total of 64 patients, with 52 in the typical and 12 in the IM group were analyzed. The commonest symptom was hematuria (59.38%), followed by irritative bladder symptoms (51.56%). The median follow-up period was 5 years and 5 months (range: 7–96 months) and no patient progressed to adenocarcinoma. On comparing the two groups, the lesions weresignificantly more extensive in the IM group (50% vs. 15.38%). However, there were no differences in the symptoms or the development of malignancy between the two groups.

Conclusions:

At a median of 5 years and 5 months of follow up, CCG (including the IM-type) did not show any increase in the risk of malignancy.

Inflammation and Tissue Remodeling in the Bladder and Urethra in Feline Interstitial Cystitis

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating chronic disease of unknown etiology. A naturally occurring disease termed feline interstitial cystitis (FIC) reproduces many features of IC/BPS patients. To gain insights into mechanisms underlying IC/BPS, we investigated pathological changes in the lamina propria (LP) of the bladder and proximal urethra in cats with FIC, using histological and molecular methods. Compared to control cat tissue, we found an increased number of de-granulated mast cells, accumulation of leukocytes, increased cyclooxygenase (COX)-1 expression in the bladder LP, and increased COX-2 expression in the urethra LP from cats with FIC. We also found increased suburothelial proliferation, evidenced by mucosal von Brunn’s nests, neovascularization and alterations in elastin content. Scanning electron microscopy revealed normal appearance of the superficial urethral epithelium, including the neuroendocrine cells (termed paraneurons), in FIC urethrae. Together, these histological findings suggest the presence of chronic inflammation of unknown origin leading to tissue remodeling. Since the mucosa functions as part of a “sensory network” and urothelial cells, nerves and other cells in the LP are influenced by the composition of the underlying tissues including the vasculature, the changes observed in the present study may alter the communication of sensory information between different cellular components. This type of mucosal signaling can also extend to the urethra, where recent evidence has revealed that the urethral epithelium is likely to be part of a signaling system involving paraneurons and sensory nerves. Taken together, our data suggest a more prominent role for chronic inflammation and tissue remodeling than previously thought, which may result in alterations in mucosal signaling within the urinary bladder and proximal urethra that may contribute to altered sensations and pain in cats and humans with this syndrome.

Evolving concepts and use of immunohistochemical biomarkers in flat non-neoplastic urothelial lesions: WHO 2016 classification update with diagnostic algorithm

CONTEXT

The classification of flat non-neoplastic urothelial lesions has been evolved through the years in the attempt to better define a spectrum of morphologic entities with somewhat overlapping features. Differentiating these lesions is important because of differences in patient management and clinical outcome. Materials and methods and objective: A systematic review of the literature has been carried out in order to (1) assess the most striking clinical features of each lesion and (2) identify those morphological traits and immunophenotypical markers which may aid in the differential diagnosis.

RESULTS AND CONCLUSION

Our results point out the importance of a proper definition of flat non-neoplastic urothelial lesions in order to predict clinical behaviour and allow tailored patient management; therefore, we attempted to construct a novel and "easy to use" algorithm for a clear, standardized and evidence-based pathological diagnosis.

Benign mimics of prostatic adenocarcinoma

Benign mimics present either as common challenges in daily routine practice or may cause diagnostic dilemmas because some are less commonly seen and one may be less familiar in recognizing them. There are a multitude of mimics of prostatic adenocarcinoma, which may represent normal gland structures, benign proliferations, atrophic lesions, hyperplastic or metaplastic changes, and inflammatory processes. Some of them are preferentially found in certain anatomic areas of the prostate, either confined to the prostate, or outside of the gland. Various benign mimics of prostatic carcinoma may be also evaluated based on their morphologic similarity to Gleason patterns 3-5 of prostatic adenocarcinoma. Most of the mimics are easily recognizable in larger specimens, such as TUR of the prostate or radical prostatectomy specimens, but they may pose diagnostic problems when the evaluation is done on limited tissue, such as needle-core biopsies or if prostate specimens are infrequently encountered in practice. Therefore, before signing out a report with a diagnosis of prostatic carcinoma, pathologists should carefully consider and rule out the various benign lesions that may mimic carcinoma. This is particularly relevant in the current prostate biopsy practice which relies on using extended biopsy core templates. The awareness and familiarity with the characteristic features of the mimics and judicial use of additional ancillary tests, including immunohistochemistry can prevent overdiagnosis and false-positive interpretation. This review provides a contemporary update on the broad spectrum of the benign prostatic lesions that can mimic prostate adenocarcinoma, outlines their key morphologic and immunohistochemical diagnostic features, and provides a diagnostic, pattern-based approach in establishing a correct diagnosis and distinguishing them reliably from prostatic adenocarcinoma.

Cystitis Cystica as a Large Solitary Bladder Cyst

Background: In this case we describe the rare and not previously documented presentation of cystitis cystica as a large solitary cystic lesion within the bladder wall.

Case Presentation: We present a case of a 46-year-old Russian male with a history of lower urinary tract symptoms and suprapubic pain. CT urogram showed a 5.8 cm filling defect/cystic mass related to the base of the bladder and prostate with 8 mm thick wall. The patient underwent cystoscopy and contrast study of bladder lesion with urethral dilatation and transurethral deroofing of bladder wall cyst under general anesthesia. A histologic diagnosis of cystitis cystica was made.

Conclusion: This case described the rare presentation of a large solitary bladder cyst arising from the anterior bladder wall, identified histologically as cystitis cystica. Cystitis cystica presenting as a large cystic lesion of the bladder wall is rare; however, a diagnosis of cystitis cystica should be considered in unexplained cystic defects of the bladder wall.

Intestinal metaplasia of the bladder in 89 patients: a study with emphasis on long-term outcome

Background

Intestinal metaplasia of the bladder is an uncommon glandular proliferation. We examined a large series of intestinal metaplasia for the clinicopathological features and discuss the significance of this lesion.

Methods

All cases of intestinal metaplasia diagnosed in our institution between 1990 and 2014 were retrospectively reviewed. Patients with a history of urothelial carcinoma or concurrent adenocarcinoma were excluded. Patient characteristics, pathological features, and follow-up outcomes were obtained.

Results

We identified 89 patients with intestinal metaplasia during this period. Sixty seven were men and 22 were women. Mean age at diagnosis was 57 years (range 23–81). Common presenting complaints included haematuria (73 cases), mucosuria (13 cases), and irritative voiding symptoms (seven cases). The majority of intestinal metaplasias located on or near the trigone (67 cases). Eighty-two patients underwent transurethral resection of their lesions. Partial cystectomy was performed in the remaining seven patients. The mean follow-up of 78 patients was 105 months (range 6–255). One case of bladder adenocarcinoma was indentified 6 months later. The initial histologic findings had revealed intestinal metaplasia with severe dysplasia. Four patients presented recurrence during the follow-up, and this occurred 9, 13, 17 and 24 months after the surgery.

Conclusions

Although intestinal metaplasia can be treated effectively by transurethral resection in most cases, its potential malignancy need to be taken into consideration after the evidence of recurrences and its association with bladder adenocarcinoma. Therefore, it is necessary to perform close surveillance following the surgery, particularly in patients with dysplastic changes.

The pathology of urinary bladder lesions with an inverted growth pattern

Inverted lesions in the urinary bladder have been the source of some difficulty in urological pathology. The two common ones are von Brunn's nests and cystitis cystic/cystitis glandularis, which are considered normal variants of urothelium. Apart from them, a number of other rare urothelial lesions with inverted growth pattern occur in the urinary bladder. Some of them are only reactive conditions, just as pseudocarcinomatous hyperplasia. Some are benign tumors, namely inverted papilloma. Whereas others are malignant neoplasms, including inverted papillary urothelial neoplasm of low malignant potential (PUNLMP), non-invasive inverted papillary urothelial carcinoma (low-grade and high-grade), and invasive urothelial carcinoma (inverted, nested and big nested variants). Because of the overlapping morphological features of all the inverted lesions mentioned above, even between high-grade invasive carcinoma and pseudocarcinomatous hyperplasia which are only a kind of reactive conditions, it is very important for the surgical pathologist to recognize and be familiar with these inverted lesions in urinary bladder. In this article, we review these spectrums of inverted lesions of the urinary bladder. Emphasis is placed on histogenesis, morphology, differential diagnosis of these lesions, and the pathologic grading of the non-invasive inverted neoplasms, such as inverted papilloma, inverted PUNLMP, non-invasive inverted papillary urothelial carcinoma with low-grade, and non-invasive inverted papillary urothelial carcinoma with high-grade.

A Rare Urachal Cyst in a Case of Ketamine-induced Cystitis Provides Mechanistic Insights

OBJECTIVE

To establish whether the urothelial ulceration observed in ketamine-induced cystitis is triggered by urinary or systemic factors. This was achieved with a rare case where an urachal cyst was found near the bladder dome in a patient undergoing cystectomy for unremitting pain following ketamine abuse.

METHODS

Clinical investigations included cystoscopy, video urodynamic investigation, and computed tomography of the kidneys, ureters, and bladder. Histological staining was combined with immunoperoxidase labeling for markers of transitional epithelial differentiation.

RESULTS

The urachus found near the dome of the bladder was observed to be a separate cyst, with no evidence of patency found during surgery or video urodynamic investigation. The urachus was lined by a mildly reactive metaplastic epithelium of mixed transitional and columnar morphologies. Evidence of widespread cytokeratin 13, basal p75(NTR), and sparse superficial uroplakin 3a immunoreactivity suggested the urachal epithelium was fundamentally transitional in nature. Near total loss of bladder urothelium was observed from regions in contact with urine, whereas the urachal epithelium (not exposed to urine) remained healthy.

CONCLUSION

This study supports the hypothesis that urinary (and not systemic) factors are the main driver of urothelial ulceration in ketamine-induced cystitis. The most likely excreted factors responsible are ketamine and potentially its metabolites. This study reinforces the importance of complete cessation of ketamine use in patients with ketamine-induced cystitis.

Baseline Prostate Atrophy is Associated with Reduced Risk of Prostate Cancer in Men Undergoing Repeat Prostate Biopsy

PURPOSE

We evaluated whether the presence and severity of baseline prostate atrophy in men with initial biopsy negative for prostate cancer was associated the risk of subsequent prostate cancer detection in a clinical trial with scheduled study mandated biopsies.

MATERIALS AND METHODS

We retrospectively analyzed the records of 3,084 men 50 to 75 years old with prostate specific antigen between 2.5 and 10 ng/ml, and a prior negative biopsy in the placebo arm of the REDUCE (Reduction by Dutasteride of Prostate Cancer Events) study who completed at least 1 per-protocol biopsy. Prostate cancer (defined as present or absent) and prostate atrophy (graded as absent, mild or moderate/marked) was assessed by central pathology review. The association of baseline atrophy with positive 2 and 4-year repeat biopsies was evaluated with logistic regression, controlling for baseline covariates.

RESULTS

Baseline prostate atrophy was detected in 2,143 men (70%) and graded as mild and moderate/marked in 1,843 (60%) and 300 (10%) baseline biopsies, respectively. Patients with atrophy were older and had a larger prostate, and more acute and chronic prostate inflammation. At 2-year biopsy the prostate cancer incidence was 17% (508 cases). Baseline atrophy was significantly associated with lower prostate cancer risk (univariable and multivariable OR 0.60, 95% CI 0.50-0.74 and OR 0.67, 95% CI 0.54-0.83, p <0.001, respectively) at the 2-year biopsy. These results were similar at the 4-year biopsy (univariable and multivariable OR 0.70, 95% CI 0.53-0.93 and OR 0.72, 95% CI 0.53-0.97, p = 0.03, respectively). Relative to no atrophy the prostate cancer risk at the 2-year repeat biopsy was lower for mild atrophy (OR 0.69, 95% CI 0.55-0.86) and moderate/marked atrophy (OR 0.51, 95% CI 0.34-0.76, each p <0.001).

CONCLUSIONS

Baseline prostate atrophy in men with a prostate biopsy negative for prostate cancer was independently associated with subsequent lower prostate cancer detection.