A Case Report of Calyceal Diverticulum: Differential Diagnosis for Organ-Preserving Operations.

Calyceal diverticula and epidermal cysts are extremely rare kidney lesions with unknown etiology and pathogenesis. They have non-specific clinical and radiological picture. Despite the benign nature, sometimes these disorders mimic malignant tumors leading to unjustified nephrectomy. We present a clinical and morphological observation of a multicystic lesion in a 76-year-old patient's right kidney filled with keratinized masses and imitating a malignant solid tumor. The detailed gross, histological and immunohistochemical (desmin, cytokeratin 7, uroplakin and p63) analyses of the kidney tissue excluded the malignant nature of the lesion. The final differential diagnosis was between an epidermal cyst and calyceal diverticulum with pronounced squamous cell metaplasia of urothelium. The upper pole localization of the lesion, its connection with the pelvicalyceal system through the unobstructed isthmus, the presence of urothelial lining and smooth muscle cells in its wall let us diagnose a calyceal diverticulum type I. Knowledge of the key clinical and morphological features of epidermal cysts and diverticula of the pelvicalyceal system will help the practicing physicians suspect the benign nature of such lesions and perform organ-preserving operations.

Evaluation of Supercritical CO2-Assisted Protocols in a Model of Ovine Aortic Root Decellularization.

One of the leading trends in the modern tissue engineering is the development of new effective methods of decellularization aimed at the removal of cellular components from a donor tissue, reducing its immunogenicity and the risk of rejection. Supercritical CO2 (scCO2)-assisted processing has been proposed to improve the outcome of decellularization, reduce contamination and time costs. The resulting products can serve as personalized tools for tissue-engineering therapy of various somatic pathologies. However, the decellularization of heterogeneous 3D structures, such as the aortic root, requires optimization of the parameters, including preconditioning medium composition, the type of co-solvent, values of pressure and temperature inside the scCO2 reactor, etc. In our work, using an ovine aortic root model, we performed a comparative analysis of the effectiveness of decellularization approaches based on various combinations of these parameters. The protocols were based on the combinations of treatments in alkaline, ethanol or detergent solutions with scCO2-assisted processing at different modes. Histological analysis demonstrated favorable effects of the preconditioning in a detergent solution. Following processing in scCO2 medium provided a high decellularization degree, reduced cytotoxicity, and increased ultimate tensile strength and Young's modulus of the aortic valve leaflets, while the integrity of the extracellular matrix was preserved.

Transurethral resection of a large bladder hemangioma of mixed histological composition: a case report.

Hemangioma is a rare benign vascular tumor of the bladder, which occurs mainly in children. It has no specific clinical symptoms but can result in severe and fatal complications as well as relapse. In the current clinical observation, a 35-year-old patient had a large solid tumor of the bladder spreading into the muscular layer. In histological and immunohistochemical analyses, verified hemangioma consisted of capillary, cavernous and arterio-venous components. The patient underwent transurethral resection of the bladder using computer chromoendoscopy. It is the first to the best of our knowledge complete transurethral removal of 3 cm in diameter bladder hemangioma.