37 y/o African male with hematuria. Cystsoscopy demonstrated many raised hemorrhagic foci and multiple calcified nodules throughout the bladder.
The specimen consists of reactive urothelium with numerous ova in a background of severe acute granulomatous inflammation (Fig 1-6).
- Granulomatous inflammation due to bacterial, fungal or other causes
- Schistosomiasis, active form
Schistosomiasis, active form
Worldwide, schistosomiasis is the leading cause of hematuria. Schistosoma haematobium resides in the paravesical veins and is the cause of schistosomiasis of the urinary bladder. The eggs of Schistosoma haematobium are deposited within these veins and may pass into the lumen of the bladder or lodge in the bladder wall. Here, a vigorous granulomatous inflammatory response ensues and calcification is frequent. Schistosoma haematobium is not acid-fast, while other human schistosomes (S. mansoni, interculatum, and japonicum) are acid-fast.
Active schistosomiasis, most commonly diagnosed by the discovery of urine examination, is the result of flatworms’ depositing eggs. The inflammatory response may cause ulcers or polypoid masses that can obstruct either the ureters or urethra. Metaplastic changes, including keratinizing squamous or intestinal metaplasia, are common as well. The inactive form of schistosomiasis is characterized by calcified eggs.
Importantly, schistosomiasis is associated with squamous cell carcinoma of the urinary bladder. Typically, adjacent non-neoplastic bladder has undergone keratinizing squamous metaplasia.
- Smith JH, Christie JD. The pathobiology of Schistosoma haematobium infection in humans. Hum Pathol 1986; 17:333-345.
- Cheever AW. Schistosomiasis and neoplasia. J Natl Cancer Inst 1978; 61: 13-18.