IS A CYSTIC LESION LOCATED AT THE MIDLINE OF THE PROSTATE A MULLERIANDUCT CYST - ANALYSIS OF ASPIRATED FLUID AND HISTOPATHOLOGICAL STUDY OF THE CYST WALL

Objective: In 6 patients, ranging in age from 26 to 71 years, we analy zed aspirated fluid and histologically studied cystic lesions located at the midline of the prostate. Methods: Digital rectal examination, u ltrasonography, magnetic resonance imaging, and aspiration of cystic f luid were performed to evaluate size, contents, and location of the cy stic lesion. A 22-gauge needle was inserted into the cystic lesion per ineally under ultrasound guidance. After extracting fluid for cytology and measurement of prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP), a specimen from the prostate involving the cystic wall was collected. Hematoxylin-eosin staining and immunohistochemical staining for PSA were performed. Results: All aspirated fluid specime ns were yellowish and clear without any sperm or malignant cells, The PSA levels in the fluid ranged between 90 and 670 x 10(4) ng/ml, while the PAP levels were between 168 and 4,000 ng/ml. These levels of PSA and PAP were significantly higher as compared with those in the serum. The cystic wall was lilted with cuboidal or columnar epithelium. Some epithelial cells from the cystic wall showed positive immunostaining for PSA. Conclusions: Not all cystic lesions located at the midline of the prostate are mullerian duct cysts, and there is a high probabilit y that the lesion could be a cystadenoma or a simple cyst of the prost ate.