Aims: Keratinizing squamous metaplasia is infrequently found in bladder biopsies and its clinical significance remains unclear, with studies linking it to the development of invasive squamous cell carcinoma. Once diagnosed, there is a dilemma how to treat and follow-up this group. Methods: We reviewed the literature on the topic with particular emphasis on natural history, management and subsequent follow-up. Results: Keratinizing squamous metaplasia of the bladder is rare. Pathognomonic findings on biopsy are required to confirm the diagnosis. Both synchronous diagnosis of urothelial tumour and subsequent tumour development on follow-up has been identified. Risk of malignant transformation increases in the presence of dysplasia as well as with extensive keratinization. Lesions should be treated with local transurethral resection. Considering the lack of evidence cystectomy cannot be justified for those with extensive lesions. Conclusion: Currently there is not enough data to identify keratinizing squamous metaplasia of the bladder as a pre-malignant condition; this term being reserved for those with obvious histological dysplasia. However at present all patients should undergo regular follow-up.
© 2008 S. Karger AG, Basel
- Keratinizing squamous metaplasia
- Squamous cell carcinoma
- Connery DB: Leukoplakia of the urinary bladder and its association with carcinoma. J Urol 1953;69:121–127.
- Khan MS, Thornhill JA, Gaffney E, Loftus B, Butler MB: Keratinizing squamous metaplasia of the bladder: natural history and rationalization of management based on review of 54 years experience. Eur Urol 2002;42:469–474.
- Morgan RJ, Cameron KM: Vesical leukoplakia. Br J Urol 1980;52:96–100.
- Mueller SC, Thueroff JW, Rumpelt HJ: Urothelial leukoplakia: new aspects of aetiology and therapy. J Urol 1987;137:979–983.
- Ozbey I, Aksoy Y, Polat O, Bicgi O, Demirel A: Squamous metaplasia of the bladder: findings in 18 patients and review of the literature. Int Urol Nephrol 1999;31:457–461.
- Akdas A, Turkeri L: The impact of squamous metaplasia in transitional cell carcinoma of the bladder. Int Urol Nephrol 1991;23:333–336.
- Benson Jr RC, Swanson SK, Farrow GM: Relationship of leukoplakia to urothelial malignancy. J Urol 1984;131:507–511.
- Højgaard AD, Jessen AL: A case of vesical leukoplakia. Acta Obstet Gynecol Scand 1991;70:623–624.
- Guo CC, Fine SW, Epstein JI: Noninvasive squamous lesions in the urinary bladder. Am J Surg Pathol 2006;30:883–891.
- Reece RW, Koontz WW Jr: Leukoplakia of the urinary tract: a review. J Urol 1975;114:165–171.
- Marion G: Leukoplakia of the bladder. J Urol 1920;9:257–261.
- Abeshouse BS, Tankin LH: Leukoplakia of the renal pelvis and bladder. J Urol 1953;76:330–337.
- Wiener DP, Koss LG, Sablay B, Freed SZ: The prevalence and significance of Brunn’s nests, cystitis cystica and squamous metaplasia in normal bladders. J Urol 1979;122:317–321.
- Delnay KM, Stonehill WH, Goldman H, Jukkola AF, Dmochowski RR: Bladder histological changes associated with chronic indwelling urinary catheter. J Urol 1999;161:1106–1108; discussion 1108–1109.
- Kvist E, Sjolin KE, Laursen H, Orntoft TF, Sanchez Sturmer MA: Squamous metaplasia of the bladder urothelium. A retrospective study of 36 patients. AMPIS 1992;100:650–654.
- Lopez-Beltran A, Cheng L, Andersson LC, Brausi M, De Matteis A, Montironi R, Sesterhenn I, van det Kwast T, Mazerolles C: Preneoplastic non-papillary lesions and conditions of the urinary bladder. An update based on the Ancona International Consultation. Virchows Arch 2002;440:3–11.
- Roehrborn CG, Teigland CM, Spence HM: Progression of leukoplakia of the bladder to squamous cell carcinoma 19 years after complete urinary diversion. J Urol 1988;140:603–604.
- O’Flynn JD, Mullaney J: Leukoplakia of the bladder. A report on 20 cases, including 2 cases progressing to squamous cell carcinoma. Br J Urol 1967;39:461–471.
- Holley PS, Mellinger GT: Leukoplakia of the bladder and carcinoma. J Urol 1961;86:235–241.
- DeKock MLS, Anderson CK, Clark PB: Vesical leukoplakia progressing to squamous cell carcinoma in women. Br J Urol 1981;53:315–317.
- Walts AE, Sacks SA: Squamous metaplasia and invasive epidermoid carcinoma of bladder. Urology 1977;9:317–320.
- Zachwiej J, Witeska A, Plaszczynski J: Tumor of the urinary bladder preceded by vesical leukoplakia. Int Urol Nephrol 1981;13:147–152.
- Hodder SL, Mahmoud AA, Sorenson K, Weinert DM, Stein RL, Ouma JH, Koech D, King CH: Predisposition to urinary tract epithelial metaplasia in Schistosoma haematobium infection. Am J Trop Med Hyg 2000; 63:133–138.
Beatson Institute for Cancer Research
Garscube Estate, Switchback Road
Bearsden, Glasgow G61 1BD (UK)
Tel. +44 141 330 3973, Fax +44 141 201 2987, E-Mail email@example.com
Number of Print Pages : 5
Number of Figures : 2, Number of Tables : 1, Number of References : 23
Vol. 81, No. 3, Year 2008 (Cover Date: October 2008)
Journal Editor: Wirth M.P. (Dresden), Porena M. (Perugia), Hakenberg O.W. (Rostock), Castro-Diaz D. (Santa Cruz de Tenerife)
ISSN: 0042–1138 (Print), eISSN: 1423–0399 (Online)
For additional information: http://www.karger.com/UIN
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher or, in the case of photocopying, direct payment of a specified fee to the Copyright Clearance Center.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in goverment regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.