Histopathology of Anterior Urethral Strictures: Toward a Better Understanding of Stricture Pathophysiology.

PURPOSE: Histopathology can provide insights into disease mechanisms but to date it has been poorly described for urethral stricture. The purpose of this study was to comprehensively describe histopathological findings of stricture specimens obtained at the time of anterior urethroplasty. MATERIALS AND METHODS: All pathological specimens of men who underwent anterior urethroplasty of urethral stricture disease from 2010 to 2017 at a single institution were rereviewed by a single blinded pathologist directed to rule out lichen sclerosus and then describe inflammatory cell type and severity when present. Cohorts comprising strictures with no inflammation, minimal to mild inflammation or moderate to severe inflammation were developed and stricture, patient and surgical outcome characteristics were compared. RESULTS: Histopathology slides from 100 anterior urethroplasty cases were reviewed. Two or more lichen sclerosus characteristics were present in 21% of specimens and 44% of specimens showed chronic inflammation, which was minimal in 20%, mild in 39%, moderate in 39% and severe in 2%. Lymphocytes in 86% of specimens and plasma cells in 12% were the predominant cell types. Patients with inflammatory stricture reported worse overall health. Inflammation was largely absent from isolated bulbomembranous strictures (9%) and more common in lichen sclerosus strictures (100%). The 11% overall failure rate was not affected by the presence (7%) or absence (14%) of inflammation. CONCLUSIONS: Chronic inflammation is prevalent in a significant percent of urethral stricture disease specimens. Associations with worse overall health suggest systemic mediators. Absent inflammation in bulbomembranous strictures suggests a unique pathophysiology in this region. The presence of inflammation did not affect surgical outcomes at mid-term followup.

Urethral lichen sclerosus under the microscope: a survey of academic pathologists.

INTRODUCTION: Given the poor understanding of the pathophysiology of genital lichen sclerosus (GLS) and a lack of accepted definitive diagnostic criteria, we proposed to survey pathologists regarding their understanding of GLS. We hypothesized that significant disagreement about GLS will exist. MATERIALS AND METHODS: All urologists participating in the Trauma and Urologic Reconstruction Network of Surgeons identified genitourinary (GUP) and dermatopathologists (DP) at their respective institutions who were then invited to participate in an online survey regarding their experience with diagnosing GLS, GLS pathophysiology and its relationship to urethral stricture disease. RESULTS: There were 23 (12 DP, 11 GUP) pathologists that completed the survey. The most agreed upon criteria for diagnosis were dermal collagen homogenization (85.7%), loss of the normal rete pattern (33.3%) and atrophic epidermis (28.5%). No pathologists believed GLS had an infectious etiology (19% maybe, 42% unknown) and 19% believed GLS to be an autoimmune disorder (42% maybe, 38% unknown); 19% believed LS to be premalignant, but 52% believed it was associated with cancer; 80% believed that LS could involve the urethra (DP (92%) versus GUP (67%); p = 0.272). Of those diagnosing urethral GLS, 80% of DUP believed that GLS must first involve the glans/prepuce before involving the urethra, while all GUP believed that urethral disease could exist in isolation (p = 0.007). CONCLUSIONS: There was significant disagreement in this specialized cohort of pathologists when diagnosing GLS. A logical first step appears to be improving agreement on how to best describe and classify the disease. This may lead to improve treatments.

Epithelial-Mesenchymal Transition Protein Expression in Basal Cell Adenomas and Basal Cell Adenocarcinomas.

Basal cell adenomas and basal cell adenocarcinomas show marked histomorphologic similarity and are separated microscopically primarily by the invasive characteristics of the adenocarcinomas. We wished to explore potential differences in the expression of epithelial-mesenchymal transition associated proteins in these two tumor types. A tissue microarray was constructed utilizing 29 basal cell adenomas and 16 basal cell adenocarcinomas. Immunohistochemical expression of E-cadherin, beta-catenin, Twist 1 and vimentin were investigated. Both tumors expressed all proteins in a relatively similar manner. Nuclear beta-catenin was essentially limited to the abluminal cell populations in both tumor types. E-cadherin was limited largely to luminal locations but was more prevalent in the adenocarcinomas as compared to the adenomas. Primarily abluminal expression for vimentin was seen, sometimes present in an apical dot-like pattern. Distinct populations of cellular expression of these four markers of epithelial mesenchymal transition were present but were similar in locations in both tumors with no patterns discerned to separate basal cell adenoma from basal cell adenocarcinoma. Given these findings, the mechanisms by which basal cell adenocarcinoma is able to invade while its counterpart, basal cell adenoma can not, may be more complex than in other tumor types.