CASE OF THE WEEK
2019-43 / DECEMBER 16
(CONTRIBUTOR: BHUVANESWARI KRISHNAN )
A 55 year old male had neurogenic bladder secondary to spinal cord injury and paraplegia. The patient performs self-catheterization for urination. He had history of repeated urinary tract infections with cultures showing Klebsiella and E. coli infections. He complained of bleeding during catheterization two months prior to the presentation. A cystoscopy showed diffuse erythema in the dome of the bladder and a nodule in the anterior wall of the bladder. A biopsy of the nodule was performed.
Quiz
1. What is the correct diagnosis?
a. Urothelial carcinoma with lamina propria invasion
b. Malakoplakia
c. Melanoma
d. Granulomatous cystitis
1. b
1. Malakoplakia
Malakoplakia can be seen in multiple sites, but urinary bladder is the most common location. It is more common in females than males. It is thought to be secondary to infection and defective phagocytosis of the bacterial products by histiocytes. This is seen as target like inclusions in the cytoplasm of the histiocytes, called the Michaelis-Guttman bodies. These cytoplasmic bodies are positive by the Von Kossa stain for calcium. The histiocytes express CD68 by immunohistochemistry. Generally, there is associated lymphoplasmacytic infiltrates.
The differential diagnostic considerations include, urothelial carcinoma, granulomatous cystitis secondary to Mycobacterial infection, Leukemic infiltration, metastatic malignancies like melanoma or carcinoma. Unlike Malakoplakia, the carcinoma and melanoma will show cytokeratin and S-100 respectively by immunohistochemistry.
Coleman JF, Hansel DE. Benign Diseases of the Bladder.
Surg Pathol Clin. 2008 Dec;1(1):129-58
Bhuvaneswari Krishnan
Michael E. DeBakey VA Medical Center and Baylor College of Medicine. Houston, TX
Krishnan@bcm.edu
Bladder
Malakoplakia, Granulomatous cystitis, Urothelial carcinoma