Mucinous metaplasia of the penis

Aims: To determine the incidence of mucinous metaplasia occurring in the foreskin or glans penis and any associated clinical or histopathological features. Methods and results: Following the recognition of two index cases, 100 other foreskin specimens were retrieved from the histopathology archives at Southampton General Hospital. The haematoxylin and eosin-stained slides were examined by a single observer to detect the presence of mucin-producing cells in the surface epithelium. The absence of mucinous metaplasia in negative cases was confirmed with mucin histochemistry. In total, four cases of mucinous metaplasia were identified, three involving the foreskin and one involving the glans penis. The age range was 51-80 years. Three cases were associated with Zoon's balanitis and the fourth showed mild non-specific balanitis. All four cases showed positive staining with both diastase periodic acid-Schiff and alcian blue. No mucin-producing cells were identified in non-inflamed or minimally inflamed specimens. Conclusions: Mucinous metaplasia of the penis is an uncommon but under-recognized condition. It is seen in the elderly and appears to be a metaplastic change associated with severe chronic inflammation, and possibly more specifically with Zoon's balanitis. Our study identified a case affecting the glans penis, a site not previously recorded.