A 54-year-old Sudanese immigrant is evaluated for several months of intermittent dysuria and gross hematuria. The patient notes that he passes blood at the end of urination but has no associated pain. Cystoscopy reveals erythematous areas in the bladder mucosa. Multiple biopsies are taken from the affected sites; histopathological findings are shown in the image below. Which of the following most likely predisposed this patient to his current condition?

Question

A 54-year-old Sudanese immigrant is evaluated for several months of intermittent dysuria and gross hematuria.  The patient notes that he passes blood at the end of urination but has no associated pain.  Cystoscopy reveals erythematous areas in the bladder mucosa.  Multiple biopsies are taken from the affected sites; histopathological findings are shown in the image below.  Which of the following most likely predisposed this patient to his current condition?

Quizplus · Accepted Answer

11ec160b_399d_8b34_9249_7323a372ed92_MD0001_00 Schistosomiasis is a parasitic blood fluke infection endemic to rural areas of sub-Saharan Africa, Asia, and South America. Transmission occurs when humans bathe in freshwater ponds, lakes, or rivers contaminated with cercariae from infected snails. Cercariae penetrate the dermis and travel to the liver, where they evolve into adult worms and subsequently migrate into the venules in the walls of the intestines, colon, or bladder. Because adult schistosomes absorb host proteins and display host antigens on their surface, they are relatively protected from immune recognition and generally do not cause symptoms. However, adult worms shed eggs into the circulation that travel through host tissues and induce eosinophilic granulomatous inflammation and fibrosis (as seen in the image above). This can lead to indolent symptoms in the liver, spleen, bowel wall, and genitourinary system. One characteristic manifestation of genitourinary schistosomiasis is the development of hematuria at the end of voiding ("terminal hematuria") due to bladder wall inflammation and ulcers; urinary calcifications, obstruction, and bladder cancer may eventually develop. (Choice A) Benign prostatic hyperplasia can cause chronic urinary tract obstruction. Patients usually have difficulty voiding urine (eg, slow stream, hesitancy), frequency, urgency, and/or nocturia. (Choice C) Cyclophosphamide is a common cause of hemorrhagic cystitis in patients undergoing chemotherapy for cancer or chronic rheumatologic conditions. Cystoscopy may show bladder irritation, but eggs would not be seen on biopsy. (Choice D) Cigarette smoking is a major risk factor for the development of bladder cancer (usually transitional cell carcinoma), which classically presents with painless hematuria. However, cystoscopy generally shows a mass, and biopsy would reveal malignant cells, not eggs. (Choice E) Genitourinary infections with bacteria that split urea such as Proteus mirabilis are frequently associated with the formation of urinary stones. Nephrolithiasis can cause hematuria but is usually very painful. Educational objective: Schistosomiasis is a parasitic blood fluke infection that is associated with bathing in freshwater contaminated with cercariae from infected snails. Patients often are asymptomatic for months or years but may eventually develop eosinophilic granulomatous inflammation in the liver, spleen, gastrointestinal tract, or genitourinary system. One common manifestation of genitourinary schistosomiasis is painless terminal hematuria; eggs can often be identified in the urine or on biopsy.

A 54-Year-Old Sudanese Immigrant Is Evaluated for Several Months of Intermittent