Prostate gland & seminal vesicles

• Rare chronic inflammatory reaction that affects multiple sites, most commonly the bladder and rarely the prostate

• Multiparametric magnetic resonance imaging (mpMRI) with hypointense lesion(s), which may correspond to higher prostate imaging reporting and data system (PI-RADS) scores (Urol Case Rep 2020;32:101222)

Images hosted on other servers:

• 43 year old man with fever and elevated PSA (Int J Clin Exp Pathol 2018;11:4153)
• 57 year old man with rising PSA over 3 years (Urol Case Rep 2020;32:101222)
• 61 year old man with recurrent E. coli urinary tract infection and months of urinary obstruction symptoms (J Endourol Case Rep 2020;6:231)
• 63 year old man with persistently elevated PSA (Urol Case Rep 2017;18:94)
• 75 year old man with elevated PSA (J Endourol Case Rep 2017;3:74)

Contributed by Theodorus van der Kwast, M.D., Ph.D.

• Prostatic adenocarcinoma:
  • Small glands with nuclear enlargement, hyperchromasia and prominent nucleoli
  • May be associated with acute or chronic inflammation but histiocytic inflammation is not typically identified (Ann Diagn Pathol 2016;24:55)
  • Lacks Michaelis-Gutmann bodies
  • Positive for AE1 / AE3
  • Negative for CD68 and CD163
• Xanthogranulomatous inflammation:
  • Collections of histiocytes with abundant foamy cytoplasm
  • Lacks Michaelis-Gutmann bodies
  • Negative for von Kossa and Prussian blue
• Infectious granulomatous prostatitis, tuberculous prostatitis:
  • Central caseous necrosis surrounded by epithelioid histiocytes, plasma cells and multinucleated giant cells
  • Negative for von Kossa and Prussian blue
• Nonspecific granulomatous prostatitis:
  • Lacks Michaelis-Gutmann bodies
  • Negative for von Kossa and Prussian blue

A 57 year old man presents with a transurethral resection of the prostate showing the above images (H&E on left, PAS stain on right). Which organism is most likely associated with this reaction?

1. Chlamydia trachomatis
2. Escherichia coli
3. Prevotella bivia
4. Staphylococcus saprophyticus

B. Escherichia coli. E. coli is one of the most commonly associated organisms which have been associated with prostatic malakoplakia and is an enteric gram negative bacillus. Prevotella bivia is another gram negative bacillus; however, is typically recovered from oral and vaginal sites. P. bivia may cause urinary tract infections; however, there has not, as of the drafting of this article, been a case associated with malakoplakia. Chlamydia trachomatis is a gram negative bacteria that is transmitted through infected secretions, infects mucosal membranes and is most commonly associated with sexually transmitted infections. Staphylococcus saprophyticus is a gram positive coccus and is associated with urinary tract infections in young women.

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Reference: Malakoplakia

A 49 year old man presents with urinary obstructive symptoms and imaging is concerning for malignancy. On histopathology, several intracytoplasmic inclusions are noted in the histiocytes. Which of the following groups of special stains would help the most with the diagnosis?

1. Prussian blue, PAS, reticulin
2. Prussian blue, PAS, von Kossa
3. Prussian blue, trichrome, von Kossa
4. Prussian blue, trichrome, reticulin

B. Prussian blue, PAS, von Kossa. Prussian blue (iron) and von Kossa (calcium) highlight Michaelis-Gutmann bodies, as they are formed from the accumulation of iron and calcium. Trichrome stains connective tissue, including collagen, while reticulin highlights reticular fibers and basement membrane materials; neither is utilized in supporting the diagnosis of malakoplakia.

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Reference: Malakoplakia