Prostatic malacoplakia: a case report with a review of 49 cases of malacoplakia of various sites in Japan.

We reported a 62-year-old man with malacoplakia of the prostate, and reviewed 49 cases of malacoplakia hitherto observed in Japan in which the lesions originated from the urogenital tract, except for one gastric case. E. Coli was emphasized as a possible causative agent for malacoplakia especially in the urogenital tract. The possible histiocytic origin of von Hansemann cells was stressed by demonstrating cytoplasmic processes and desmosomes in our prostatic case. An adjuvant use of cholinergic agents and ascorbic acid with chemotherapeutic agents was recommended for treating malacoplakia.