Faculty Bibliography

AIM: To develop and validate a technique for construction of intermediate density tissue microarray (TMA) slides based on the transfer of tissue from pre-existing routine slides provided for pathology diagnosis with validation to show preservation of morphology and antigenicity of the transferred tissue. METHODS: A prostate cancer TMA was constructed using 20 cores from radical prostatectomy slides. This technique entails removal of the coverslip on each slide and reinforcement of the tissue by covering with Mount-Quick liquid mounting medium. The attached tissue with its new scaffold is 'biopsied' using a TMA needle (1.5 mm in diameter). The resultant biopsy disc is then transferred onto a recipient slide, with adhesion of the disc to the slide accomplished using heavy pressure. The preservation of morphology and antigenicity of this TMA is tested in comparison to a traditional TMA. RESULTS: After immunohistochemical staining, 35 of 39 cores (89.7%) on the patch TMA were intact compared with 39 of 40 cores (97.5%) on the traditional TMA (p>0.1). Expression patterns and density of the antigens (34betaE12, p63 and AMACR) on the patch TMA were almost identical to the traditional TMA. CONCLUSIONS: Patch TMA represents a viable alternative for tissue-based immunohistochemistry studies when paraffin blocks are unavailable. This may be a valuable tool for allowing the use of archival slide material for immunohistochemistry and enabling a standardised TMA platform to be used when the slides sent for review from other institutions are the only source of tissue available.

OBJECTIVE: To study the histopathology changes and clinical features of vesical diverticula, focusing on the neoplastic entities. MATERIALS AND METHODS: We retrieved data for 108 patients with vesical diverticula from the archives of our institute during the past 15 years (1998 to 2012) and reviewed their clinical and pathologic characteristics. RESULTS: Diverticula most often involved the lateral wall, followed by the posterolateral and posterior walls of the urinary bladder. Nonneoplastic processes were found in 70 of 108 patients (65%), including inflammation, metaplasia, and urothelial hyperplasia, with or without atypia/dysplasia. Primary carcinomas arising within the diverticula were found in 36 patients (33.3%), of which 33 were urothelial carcinoma, including 5 with divergent differentiation, 2 with squamous carcinoma, and 1 with adenocarcinoma. Patient follow-up for neoplastic diverticula (mean, 59 months; range, 1-108 months) showed that no patients died of disease progression. Concurrent or subsequent urothelial carcinoma was present in the nondiverticular bladder in 19 of 36 patients (53%). Four patients with subsequent extradiverticular urothelial carcinoma showed progression, with pathology upstaging. CONCLUSION: Inflammation, metaplasia, and dysplasia are commonly seen in vesical diverticula. In our series, which includes patients who underwent endoscopic or surgical intervention and microscopic examination, those with vesical diverticula appeared to have a significantly higher risk for development of urothelial carcinoma, which can occur synchronously or precede carcinoma of the nondiverticular bladder. Compared with their non-diverticulum-associated counterparts, a significantly higher percentage of diverticulum-associated bladder carcinomas are high-grade and invasive. Conservative approaches are suggested for tumors confined within diverticula, after extensive investigation of the nondiverticular bladder.

Cystic changes are common in both neoplastic and non-neoplastic kidney diseases. The most important diagnostic consideration is to rule out cystic neoplasms and hereditary polycystic kidney disease for patient management. Localized cystic disease of the kidney is a rare, nongenetic and nonprogressive cystic disease that may mimic cystic neoplasms or hereditary polycystic disease. However, reports in the literature on its pathologic characteristics are scarce, and most surgical pathologists are unfamiliar with this entity. We report the clinicopathologic characteristics of 9 such cases that mimicked renal neoplasms and were treated surgically. Nine patients, including 5 men and 4 women, had a mean age of 33.3 years (range, 18 to 56 y) at diagnosis. Two patients presented with gross hematuria. In the remaining 7 patients, localized cystic disease was discovered incidentally. None had a personal history of cystic disease of the kidney or other organs or a family history of cystic renal disease. On imaging studies, solitary multilocular cystic lesions were identified in all patients with a mean size of 2.9 cm (range, 0.8 to 6 cm). Of 7 patients with documented Bosniak classification, 4 lesions were class III, and 3 lesions were class II. Follow-up was available in 5 patients, with a mean follow-up time of 14.6 months (range, 5 to 31 mo). No cysts were observed in the ipsilateral and contralateral kidneys during follow-up. Partial and total nephrectomy was performed in 8 and 1 patient, respectively. Grossly, the cystic lesions were not discrete and merged imperceptibly with the adjacent renal parenchyma without a discrete margin or capsule. Microscopically, cystic lesions involved renal papillae in all cases, and the cystic space was continuous with dilated collecting ducts. Cysts were lined with cuboidal or flat epithelial cells identical to those lining the collecting ducts. Significant inflammation was absent. The surrounding renal parenchyma was normal. With this study, we hope to raise awareness among surgical pathologists of this rare cystic lesion in order to avoid potential misdiagnosis of this lesion as a cystic neoplasm or hereditary polycystic disease. We also presented a diagnostic algorithm for working up the renal cystic lesions.