[The cytologic differentiation of prostatis (author's transl)].

INTRODUCTION

Cytologists are often confronted with unexpected prostatitis in aspiration biopsy smears, because clinically prostatitis may lead to suspicious induration of the prostate similar to carcinoma and therefore subject to diagnostic biopsy. The question is whether cytodiagnosis is a reliable method for the exact morphologic diagnosis of prostatitis. The following paper attempts to answer this question.

MATERIAL AND METHODS

The basis of our cytologic differentiation of prostatitis was a series of 129 cases of prostatitis in 664 aspiration biopsies according to Franzén. In 82 of these 129 cases, we had simultaneously performed a transrectal needle punch biopsy, which allowed a diagnostic comparison between the cytologic and histologic diagnosis with special reference to the reliability of cytology. Epithelial atypias were classified into 4 grades: Grade 1: No atypia; Grade 2: Slight atypia; Grade 3: Marked atypia; Grade 4: Malignant epithelium. Cytomorphologic characteristics of each grade are described.

RESULTS

We found 6 different types in 4 main groups of prostatitis: 1. Acute prostatitis, purulent and abscessing types. 2. Chronic prostatitis. 3. Chronic relapsing prostatitis. 4. Granulomatous prostatitis, non specific and specific types. All types showed classic cytomorphologic inflammatory criteria. Marked atypias were found in group 3 and 4. Differential diagnosis with respect to carcinoma is not difficult, however, because marked atypias in these groups of prostatitis almost always appear focally. The diagnostic agreement between cytology and histology in 82 cases was found to be 87,6%.

DISCUSSION

Our results showed that prostatis may be adequately diagnosed with cytology and may be differentiated into 6 different types. However, differentiation between periductal and interstitial forms of chronic prostatitis is impossible with cytology. Reliable cytodiagnosis of prostatitis requires a good aspiration smear, so that at least one half of slide is covered with material from the prostate. Furthermore, epithelial atypias must be present to prove the presence of prostatitis. Because of the good reliability of the cytologic differentiation of prostatitis, aspiration biopsy may be a valuable aid to the clinician in the primary diagnosis of prostatitis, especially the chronic type, which currently is sometimes uncertain.