Genitourinary schistosomiasis: life cycle and radiologic-pathologic findings.

Genitourinary schistosomiasis is produced by Schistosoma haematobium, a species of fluke that is endemic to Africa and the Middle East, and causes substantial morbidity and mortality in those regions. It also may be seen elsewhere, as a result of travel or immigration. S haematobium, one of the five fluke species that account for most human cases of schistosomiasis, is the only species that infects the genitourinary system, where it may lead to a wide spectrum of clinical symptoms and signs. In the early stages, it primarily involves the bladder and ureters; later, the kidneys and genital organs are involved. It rarely infects the colon or lungs. A definitive diagnosis of genitourinary schistosomiasis is based on findings of parasite ova at microscopic urinalysis. Clinical manifestations and radiologic imaging features also may be suggestive of the disease, even at an early stage: Hematuria, dysuria, and hemospermia, early clinical signs of an established S haematobium infection, appear within 3 months after infection. At imaging, fine ureteral calcifications that appear as a line or parallel lines on abdominopelvic radiographs and as a circular pattern on axial images from computed tomography (CT) are considered pathognomonic of early-stage schistosomiasis. Ureteritis, pyelitis, and cystitis cystica, conditions that are characterized by air bubble-like filling defects representing ova deposited in the ureter, kidney, and bladder, respectively, may be seen at intravenous urography, intravenous ureteropyelography, and CT urography. Coarse calcification, fibrosis, and strictures are signs of chronic or late-stage schistosomiasis. Such changes may be especially severe in the bladder, creating a predisposition to squamous cell carcinoma. Genital involvement, which occurs more often in men than in women, predominantly affects the prostate and seminal vesicles.

Quantitative enhancement washout analysis of solid cortical renal masses using multidetector computed tomography.

PURPOSE: The aim of the study was to prospectively assess the utility of quantitative enhancement washout method in the differentiation of benign solid renal masses from various subtypes of malignant masses using multidetector computed tomography. METHODS: In a prospective investigation from January 2009 to May 2010, 97 patients with solid renal masses underwent CT scan examination with unenhanced, arterial, parenchymal, and delayed phases. The following features were analyzed: the maximum attenuation value in each phase, attenuation difference (enhancement) of the mass in each phase from the unenhanced phase (ΔH), and parenchymal and delayed phases' washout. Of these patients, 82 (85%) underwent unilateral radical nephrectomy, 15 (15%) underwent partial nephrectomy. Group comparison was performed with the Kruskal-Wallis test and Mann-Whitney U test. RESULTS: The masses included in our study were 45 clear cell renal cell carcinomas (CCRCCs); 18 chromophobe renal cell carcinomas, 16 papillary (PRCC), 14 oncocytomas, and 4 minimal fat containing angiomyolipomas. In the arterial phase, the CCRCC was the most enhancing type and could be differentiated from other renal masses (benign or malignant) with high sensitivity and specificity. In the parenchymal phase, the CCRCCs demonstrated the highest washout. Chromophobe renal cell carcinomas showed the second highest washout in this phase. Benign lesions and PRCCs did not exhibit significant washout in this phase. In the delayed phase, the malignant lesions (with the exception of PRCCs) showed the highest washout. Benign lesions showed significant washout but less than malignant lesions. CONCLUSIONS: Multiphasic multidetector CT utilizing arterial-phase attenuation and quantitative enhancement washout method could help in the preoperative differentiation of various types of solid renal masses.