Prostatic calcification

Prostatic calcifications are a common finding in the prostate gland, especially after the age of 50. They may be solitary but usually occur in clusters ⁷.

Epidemiology

They are rare in children, infrequent below age 40, and common in those over 50. Their number and size increase with age ⁸. Reported prevalence range is very wide and can range between 7-70%¹¹.

Clinical presentation

Prostatic calcifications are most often an incidental and asymptomatic finding, but they have been associated with symptoms such as dysuria, hematuria, obstruction, or pelvic/perineal pain. Occasionally calcifications can be passed via the urethra ^1,2. 

Pathology

One of the key mechanisms for development of prostate calcifications is thought to be calcification of the corpora amylacea and simple precipitation of prostatic secretions ⁹.

Etiology

Prostatic calcification may be either primary (idiopathic) or secondary to ^2,6 :

• diabetes mellitus
• infections - e.g. tuberculosis or bacterial prostatitis
• benign prostatic hypertrophy - calcification occurs in 10%
• prostate cancer
• radiation therapy
• iatrogenic - urethral stents or surgery

Associations

• chronic pelvic pain syndrome ^4,5
• voiding dysfunction: rarely reported with large extrinsic calculi ¹¹
• large prostatic volume ¹⁰

Radiographic features

Prostate calcifications are most often bilateral and found in the posterior and lateral lobes although unilateral calcification can also be seen. 

Plain radiograph

Variable appearance from fine granules to irregular lumps and can range in size from 1 to 40 mm. If there is significant prostatic hypertrophy the calcifications can project well above the pubic symphysis ^1,2. 

Ultrasound

Calcifications appear as brightly echogenic foci that may or may not show posterior shadowing ³. 

CT

Calcifications appear as hyperattenuating foci of variable thickness ³.

MRI

Often difficult to visualize on MRI, the typical appearance is a small signal void, similar to calcifications elsewhere in the body. Gradient echo sequences, such as SWI may be better to identify calcifications.