Atrophic and Microcystic Limited Prostatic Adenocarcinomas

Area of Science:

• Uropathology
• Oncology
• Surgical Pathology

Background:

• Atrophic carcinoma and microcystic carcinoma were previously classified as variants of conventional acinar adenocarcinoma.
• Accurate classification is crucial for appropriate patient management and prognosis.

Purpose of the Study:

• To investigate the incidence and histological/cytological features of atrophic and microcystic carcinomas.
• To provide diagnostic criteria for differentiating these variants from benign prostatic glands.

Main Methods:

• Analysis of 4 cases of atrophic carcinoma and 4 cases of microcystic carcinoma.
• Review of 250 needle prostatic biopsies and 150 radical prostatectomies.
• Detailed examination of histological and cytological findings.

Main Results:

• Incidence of atrophic carcinoma: 0.8% in needle biopsies, 1.3% in radical prostatectomies.
• Incidence of microcystic carcinoma: 1.2% in prostatectomies, 0.67% in needle biopsies.
• Key histological features for atrophic carcinoma: irregular glands, infiltrative pattern, rigid lumens, intraluminal secretions.
• Key cytological features for atrophic carcinoma: scant cytoplasm, nucleomegaly, hyperchromasia, visible nucleoli.
• Microcystic carcinoma glands show marked dilatation and lumen rigidity compared to benign glands.
• Nuclei in microcystic carcinoma can be small, flattened, and hyperchromatic, posing diagnostic challenges.

Conclusions:

• Atrophic and microcystic carcinomas represent distinct entities within prostatic adenocarcinoma.
• Specific histological and cytological criteria are essential for their accurate diagnosis.
• Recognition of these variants is important, especially when cytological features can be subtle.