Liesegang rings in the setting of end-stage renal disease.

Introduction: Liesegang rings are acellular, lamellar, concentric rings of organic or inorganic material naturally formed in both biologic and environmental systems. Description in human tissue is scarce. Liesegang rings have exclusively been identified in association with pathologic disease processes and thus are not typically considered in differential diagnosis. They are usually described with cystic or inflammatory lesions. Histologically, Liesegang rings show features that are also seen in sections of parasitic ova, larvae, psammoma bodies, and by radiology as calcifications in cystic diseases of the breast and kidney. Case presentation: We noted at autopsy of a 59-year-old diabetic woman multiple black "stones" in the renal medulla. Microscopic examination demonstrated these to contain Liesegang rings. Conclusion: Liesegang rings formation should be considered in the differential diagnosis of atypical appearing deposits in the kidneys and other tissues. They may play a role in the pathogenesis of kidney stones.

Protein arginine methyltransferase 7 promotes breast cancer cell invasion through the induction of MMP9 expression.

Recent evidence points to the protein arginine methyltransferase (PRMT) family of enzymes playing critical roles in cancer. PRMT7 has been identified in several gene expression studies to be associated with increased metastasis and decreased survival in breast cancer patients. However, this has not been extensively studied. Here we report that PRMT7 expression is significantly upregulated in both primary breast tumour tissues and in breast cancer lymph node metastases. We have demonstrated that reducing PRMT7 levels in invasive breast cancer cells using RNA interference significantly decreased cell invasion in vitro and metastasis in vivo. Conversely, overexpression of PRMT7 in non-aggressive MCF7 cells enhanced their invasiveness. Furthermore, we show that PRMT7 induces the expression of matrix metalloproteinase 9 (MMP9), a well-known mediator of breast cancer metastasis. Importantly, we significantly rescued invasion of aggressive breast cancer cells depleted of PRMT7 by the exogenous expression of MMP9. Our results demonstrate that upregulation of PRMT7 in breast cancer may have a significant role in promoting cell invasion through the regulation of MMP9. This identifies PRMT7 as a novel and potentially significant biomarker and therapeutic target for breast cancer.

Urinary bladder sinuses: a novel morphologic lesion with clinical and pathologic significance.

BACKGROUND: We described urinary bladder sinuses (UBS) in the urinary bladder, characterized by segmental mucosal with muscularis mucosa invaginations into the submucosa (superficial UBS) and muscularis propria (deep UBS). MATERIALS: Radical cystectomy specimens and transurethral resections of the bladder were reviewed. RESULTS: Superficial UBS (extending up to the submucosa) were distinguished from cystitis cystica, and deep UBS differed from embryonic remnants, intramural ureters, and diverticulum by their cleft-like structures lined by the urothelium. In transurethral resections of the bladder specimens and bladder biopsy specimens, superficial UBS were identified in 13/20 cases. In radical cystectomy specimens, superficial UBS were identified in 15/50 cases, whereas deep UBS (all with associated superficial UBS) were seen in 23/50 additional cases. Deep UBS limited to the inner quarter of the muscularis propria and only reached the level of the inner third outer/middle third of the muscularis propria in 5 cases. Intraepithelial neoplasia involved the mucosa of UBS in 10 cases; this may pose diagnostic problems with invasive carcinoma. Furthermore, UBS were often associated with mucosal redundancy and hypertrophy of the muscularis propria, therefore mimicking muscle invasive cancer on pelvic examination and imaging techniques. CONCLUSIONS: Recognition of UBS is important to pathologically and clinically avoid over-staging of bladder malignancies.