Clinicomorphological Analysis of Urinary Bladder Lesions with Special Reference to Immunohistochemical Analysis of Grey Zone Lesions using Cytokeratin 20: A Cross-sectional Study

Abstract

Introduction: There is a wide range of pathological lesions that can involve the urinary bladder, such as congenital anomalies, inflammatory conditions, metaplastic lesions and tumours which are responsible for significant morbidity and mortality worldwide. Broadly, bladder lesions are categorised as neoplastic and non neoplastic. Some urothelial lesions have mixed features or a tendency to transform into urothelial carcinoma such as metaplastic lesions, inverted papillomas, atypical papillary hyperplasia, Papillary Urothelial Neoplasm of Low Malignant Potential (PUNLMP) and urothelial dysplasia. They are grouped as grey zone lesions. Identifying the malignant nature of grey zone lesions is difficult to identify by histopathological examination. Pathologists are trying to differentiate and classify bladder tumours using Immunohistochemical (IHC) markers such as Cytokeratin (CK) 20, CK-7, p53, Ki-67, etc., to help oncologists take proper decisions regarding patient management. Aim: To study the histopathological lesions of urinary bladder tumours and diagnose the malignant nature of grey zone lesions using IHC marker CK 20. Materials and Methods: This cross-sectional study of urinary bladder lesions was conducted in the Department of Pathology of Subharti Medical College, Meerut, Uttar Pradesh, India between December 2012 and October 2014. A total of 87 patients with urological complaints were selected for the study. Data related to age, sex, clinical symptoms and personal habits were noted on a working proforma. Biopsy materials were processed and stained with Haematoxylin and Eosin (H&E) for histopathological examination. The intensity of the reaction was determined in different fields, ranging from negative (0) to intense (3). Data thus obtained were analysed and presented in this paper. Results: Out of 87 cases of urinary bladder lesions, 47 (54.02%) were neoplastic, 26 (29.88%) non neoplastic and 14 (16.09%) grey zone lesions. They were more common in males, particularly in the 7th and 6th decades of life, i.e., 27 (31.03%) and 22 (25.28%) respectively. The most common histopathological finding in non neoplastic lesions was inflammatory conditions seen in 21 (80.76%) cases; Papillary urothelial carcinoma-low-grade in 26 (55.31%) cases of neoplastic lesions and PUNLMP in 8 (57.14%) cases of grey zone lesions. The result was positive with CK 20 in 5 (62.5%) cases of PUNLMP, 1 (100%) urothelial dysplasia, and 1 (100%) poorly differentiated tumour tissues but negative in 3 (37.5%) cases of PUNLMP, 2 (100%) of Adenocarcinoma and 1 (100%) case of Nested Variant of Urothelial Carcinoma (NVUC). Conclusion: CK 20 is a good IHC marker for determining the malignant nature of tissues in grey zone lesions. The results will be more reliable when used together with other markers.

Keywords

• haematuria
• metaplastic lesion
• neoplastic lesion