Indian Journal of Pathology and Microbiology

: 2016  |  Volume : 59  |  Issue : 3  |  Page : 425--426

Clear cell metaplasia of the prostatic urethra

Alessandro Del Gobbo, Francesco Pallotti 
 Division of Pathology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy

Correspondence Address:
Dr. Alessandro Del Gobbo
Division of Pathology, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via F. Sforza, 35, 20122 Milan

How to cite this article:
Del Gobbo A, Pallotti F. Clear cell metaplasia of the prostatic urethra.Indian J Pathol Microbiol 2016;59:425-426

How to cite this URL:
Del Gobbo A, Pallotti F. Clear cell metaplasia of the prostatic urethra. Indian J Pathol Microbiol [serial online] 2016 [cited 2022 Jun 25 ];59:425-426
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Full Text

Urinary mucosa is normally lined by urothelium, and it may undergo different types of metaplasia. The most common condition is represented by squamous metaplasia, and rarer forms of metaplastic urothelium include nephroid, mucinous, colonic, and signet-ring cell metaplasia.[1]

These epithelial changes are usually associated with chronic inflammation and may represent an adaptation to a chronic inflammatory injury.

In some cases, it may be associated with neoplasia, in particular, mucinous metaplasia may be a precursor of mucinous adenocarcinoma,[2] squamous metaplasia could evolve in squamous cell carcinoma,[1] and intestinal type metaplasia is reported to be associated with adenocarcinoma.[3]

A 67-year-old male underwent robotic prostatectomy for prostatic acinar cell carcinoma.

Histological examination showed the presence of a focal clear cell metaplasia of the prostatic urethra, constituted by cells with large cytoplasm, small-sized nuclei, arranged in rounded nests without an infiltrative pattern, and without mitotic figures, associated with chronic lymphocytic inflammation and vascular congestion in the stroma [Figure 1]a and [Figure 1]b.{Figure 1}

The immunophenotypic profile of these elements was coherent with the urothelial one, with strong positive staining to cytokeratin 7 [Figure 1]c, focal positive staining for cytokeratin 20 [Figure 1]d, focal and weak positive staining for p53 and negative staining for prostate-specific antigen, which excluded a prostatic origin of the epithelium; Ki67 proliferative index was <1%.

This is the first case described in the literature of a clear cell metaplasia that involves the urothelium, in particular, the urethra, which has no clinical significance but it is an interesting morphological finding.

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Conflicts of interest

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1Clouston D, Lawrentschuk N. Metaplastic conditions of the bladder. BJU Int 2013;112 Suppl 2:27-31.
2Zhang BY, Aguilar J, Yang M, Wang P, Li B. Mucinous metaplasia in urothelial tract may be the precancerous lesion of mucinous adenocarcinoma: Report of two cases and review of literature. Int J Clin Exp Med 2014;7:285-9.
3Hale CS, Huang H, Melamed J, Xu R, Roberts L, Wieczorek R, et al. Urethral adenocarcinoma associated with intestinal-type metaplasia, case report and literature review. Int J Clin Exp Pathol 2013;6:1665-70.