[Experience in the use of confocal laser endomicroscopy for the diagnosis of bladder papillary tumors]

INTRODUCTION

Visual confirmation of suspicious changes in the urinary tract mucosa is the cornerstone in the diagnosis of urothelial cancer. However, with bladder tumors, it is impossible to obtain histopathological data during cystoscopy both in white light and in photodynamic and narrow-spectrum modes, as well as with computerized chromoendoscopy. Confocal laser endomicroscopy (probe-based confocal laser endomicroscopy - pCLE) is an optical imaging technique that provides high-resolution in vivo imaging and real-time evaluation of urothelial lesions.

AIM

To assess the diagnostic capabilities of pCLE in papillary bladder tumors and compare its results with standard pathomorphological study.

MATERIALS AND METHODS

A total of 38 patients (27 men, 11 women, aged 41-82 years) with primary bladder tumors diagnosed on the imaging methods were included in the study. For the diagnosis and treatment, all patients underwent transurethral resection (TUR) of the bladder. When a standard white light cystoscopy with assessment of the entire urothelium, 10% sodium fluorescein was administrated intravenously as a contrast dye. pCLE was performed with CystoFlexTMUHD 2.6 mm (7.8 Fr) probe, which was passed through the 26 Fr resectoscope using a telescope bridge to visualize normal and pathological urothelial lesions. A laser with a wavelength of 488 nm and a speed of 8 to 12 frames per second allowed to obtain an endomicroscopic image. These images were compared with standard histopathological analysis using hematoxylin-eosin (H&E) staining of tumor fragments removed during TUR of the bladder.

RESULTS

Based on real-time pCLE, 23 patients had a diagnosis of low-grade urothelial carcinoma, while in 12 patients the endomicroscopic picture corresponded to high-grade urothelial carcinoma, 2 patients had typical changes for inflammatory process and 1 case of carcinoma in situ was suspected, which was confirmed by histopathological study. Endomicroscopic images demonstrated clear differences between normal bladder mucosa and high- and low-grade tumors. In the normal urothelium, the larger umbrella cells are located most superficially, followed by smaller intermediate cells, as well as the lamina propria with blood vessels network. In contrast, low-grade urothelial carcinoma is characterized by denser, normal-shaped small cells located superficially than a central fibrovascular core. High-grade urothelial carcinoma exhibits markedly irregular cell architecture and cellular pleomorphism.

CONCLUSION

pCLE is a promising new method for in-vivo diagnosing of bladder cancer. Our results show its potential for endoscopic determination of the histological characteristics of bladder tumors and the ability to differentiate between benign and malignant processes, as well as the histological grade of tumor cells.

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.

[The morphological and molecular genetic characteristics of nephroblastomas in immature ovarian teratoma in adult patients]

The paper describes 2 cases of immature ovarian teratoma with elements of nephroblastoma (ICD-0 code 9080/3) in patients aged 61 and 70 years. Microscopic examination revealed that both cases had blastemal cells with scant cytoplasm and basophil nuclei sticking together. Epidermal, glandular, rhabdomyoblastic, chondroid, bone, neuroectodermal, and histiocytic components were determined. Papillary and glomeruloid structures and primitive tubules were immured in the sarcomatous stroma. Immunohistochemical studies showed a strong reaction with Wilms tumor 1 (WT1), paired box gene (PAX-2), cytokeratin 7, desmin, smooth muscle actin, and α-1 antitrypsin. The recurrent tumors displayed a 1.8- to 6.1-fold increase in the level of p53. At the same time, the molecular genetic study revealed p53 gene mutation. In both cases, serous ovarian cystadenocarcinoma was misdiagnosed, ineffective chemotherapy was performed, and a recurrence occurred. The literature review revealed only 8 such cases.

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.

[BRAF-positive paucicellular variant of anaplastic carcinoma in the presence of tall cell variant papillary thyroid cancer]

To paper describes a case of paucicellular anaplastic cancer in the presence of tall cell variant papillary thyroid carcinoma. Microscopic examination showed that the differentiated component of the tumor was composed of papillary structures with tall cells, the height of which exceeded 3-4 times the width. Its anaplastic component consisted of fibrous tissue with occasional spindle-shaped cells and focal lymphocytic infiltration to the extent of 70%. The spindle-shaped cells expressed cytokeratins, β-catenin, p53, and vimentin. The tumor cells and lymphocytes showed an association with Epstein-Barr virus. Molecular genetic study of the tumor revealed the following mutations: BRAF p.Val600Glu (p.V600e was), HRAS p.His27His (p.H27H), PIK3CA p.Glu545Lys (p.E545K), TP53 p.Arg248Gln (p.R248Q).