malakoplakia is an uncommon but distinctive type of chronic granulomatous inflammation that is characterized histologically by the presence of sheets of histiocytes with granular cytoplasm ( von hansemann cells ) admixed with intracellular and extracellular basophilic laminated inclusions ( michaelis - gutmann bodies ) . the present case , however , is the first case of epididymal malacoplakia without concurrent involvement of the testis . although the exact etiology of malakoplakia remains poorly understood , it is commonly associated with microbial infections and states of diminished immune response . here we report an unusual case of malakoplakia that involved the epididymis in a 61-year - old man with a scrotal mass . a 61-year - old man presented with a painful mass of his left epididymis for several months . ultrasonography of the left epididymis revealed a mass lesion of mixed echotexture in the epididymal tail ( fig . histopathology showed an epididymal mass comprising sheets of histiocytes with granular eosinophilic cytoplasm ( fig . many of the histiocytes contained small round to oval targetoid structures that were morphologically consistent with michaelis - gutmann bodies . the patient 's postoperative recovery was uneventful and the surgical outcome has been satisfactory for 8 months . malakoplakia , derived from the greek adjective malakos ( soft ) and plaka ( plaque ) , was first described in 1902 by michaelis and gutmann and was clearly explained by mcclue in his review . epididymal malakoplakia was first described in 1968 by green , and there have been five reports of this condition in korea . malakoplakia , which typically involves the urinary tract , is an uncommon form of chronic inflammation caused by chronic infections and characterized by accumulation of macrophages . it has also been found in various sites such as the gastrointestinal tract , pancreas , liver , lymph nodes , skin , respiratory tract , adrenal gland , vagina , and brain . malacoplakia is characterized histologically by the presence of michaelis - gutmann bodies contained within von hansemann macrophages . special stains such as periodic acid schiff and von kossa for calcium can be particularly helpful in highlighting the michaelis - gutmann bodies when these are obscured within dense lymphohistiocytic infiltrate . the etiology of malakoplakia has not been fully elucidated . coliform bacteria , particularly e. coli , have been isolated from the involved sites of genitourinary malakoplakia in more than two - thirds of patients . another potential contributing factor to the development of malakoplakia is an impaired immune response . in a review by long and althausen , approximately 40% of malakoplakia cases that did not involve the urinary tract were associated with immunosuppression . the ability of phagocytes to completely digest bacteria is impaired in malakoplakia , which is thought to be related to low levels of intracellular cyclic guanosine monophosphate ( cgmp ) and diminished release of b - glucuronidase . this would explain the successful treatment of a case with the cholinergic agonist bethanechol chloride , which acts by increasing the levels of cgmp . the treatment options for malakoplakia include two main approaches : the administration of antibiotics and surgical excision , depending on the site and extent of involvement . antibiotics that can penetrate the cell membrane and concentrate in macrophages are associated with a high cure rate . treatment with trimethoprim - sulfamethoxazole may be helpful because of the ability of trimethoprim to enhance the killing of viable undigested microorganisms inside malakoplakic macrophages . also , because ciprofloxacin penetrates well into macrophages , this drug has been found to be particularly useful in patients with advanced malakoplakia . in addition to these agents , bethanechol is believed to enhance phagocytic bactericidal activity by increasing cgmp levels . if conservative treatment fails to control and diminish the malakoplakia , which is the most likely situation according to most investigators , surgical resection is needed . close follow - up of these patients is needed because multiple locations can be affected . in our case , considering the involvement of the epididymis in our patient , who had no fever and negative results on urinalysis and urine culture , excision of the epididymal mass was the best option without antibiotic therapy , and this treatment led to a satisfactory outcome .