Eggshell calcification of the urinary bladder in chronic Schistosoma haematobium infection: A radiologic-pathologic...

Chronic urinary schistosomiasis is an important cause of hematuria and genitourinary morbidity in individuals from endemic regions. In advanced disease, computed tomography (CT) may show circumferential calcification of the bladder and distal ureters, a classic pattern that can suggest the diagnosis even when laboratory tests are negative. A 38-year-old man from Mozambique, living in Portugal with human immunodeficiency virus and hepatitis B virus infections, presented with 2 months of painless gross hematuria. He denied dysuria, fever, flank pain, weight loss, prior urinary tract instrumentation, tuberculosis, or recent travel, and baseline blood tests and renal function were normal. Urinalysis showed hematuria and leukocyturia, but multiple urine examinations for Schistosoma ova and a urine Schistosoma-specific polymerase chain reaction were negative. Noncontrast CT of the abdomen and pelvis was obtained and demonstrated diffuse circumferential calcification of the urinary bladder wall with distal ureteral involvement, producing a classic "eggshell" appearance without hydronephrosis, renal stones, or intraluminal mass. Cystoscopy showed yellowish plaques and nodular mucosal lesions, and targeted bladder biopsies revealed numerous calcified Schistosoma haematobium ova within the urothelium and submucosa with chronic inflammation and stromal calcification, confirming chronic inactive infection. The patient received a single dose of praziquantel 40 mg/kg and 3 months later, hematuria had resolved and renal function was stable. This case highlights that in chronic urinary schistosomiasis, CT findings can be decisive when urine-based tests are negative.