Granulomatous prostatitis

Granulomatous prostatitis is a nodular form of chronic prostatitis. It is usually diagnised by biopsy.

Pathology

Causes

• idiopathic
• infection
• iatrogenic: (BCG,post radiation)
• systemic disease such as
  • sarcoidosis 
  • autoimmune diseases

Subtypes

One form of classificiations is as

• nonspecific granulomatous prostatitis (NSGP): considered on the commonest subtypes 4-5
• infectious
• indeterminate

Another form is as

• non specific granulomatous prostatitis
• tubercular granulomatous prostatitis
• postsurgical granulomatous prostatitis
• allergic granulomatous prostatitis
• xanthogranulomatous prostatitis

Histology

The histological form can vary dependant on the subtype ⁷

Radiographic features

General features

Often there is no definite ultrasound or MRI finding that allows a specific diagnosis of granulomatous prostatitis to be made, or differentiation from prostatic carcinoma ².

Widening of the prostatic urethra however may be a useful feature in differentiation from prostatic carcinoma ¹.

Ultrasound

May be seen as a hypoechoic nodule (~70%) or diffuse hypoechoic peripheral zone (~30%)

MRI

Three morphological MRI patterns have been described which are diffuse, nodular (tumour like), and cystic with mural nodule ³.

Signal characteristics include 

• T2: affected regions hypointense
• C+ (Gd): no enhancement following Gd-DTPA

History and etymology

It first described by F H Tanner and J R McDonald in 1943 ¹³