Afzali et al. of proteinuria. 1. Introduction It is well known that malignancy causes proteinuria with or without nephrotic syndrome [1C3]. One of the major mechanisms of proteinuria in patients with malignancy is usually deposition of tumor-related antigen and GNE-4997 antibody immune complexes in glomerulus [4]. Urothelial carcinoma may also cause proteinuria by glomerulopathy [5]. Interestingly, secreted protein from urothelial cells into urinary tract can be detected as significant proteinuria [6C8]. However, an amount of proteinuria by secreted protein from carcinoma was reported to be less than 1?g/day [3, 8]. Here we statement a patient with moderate amount of proteinuria probably caused by secreted protein of urothelial carcinoma. 2. Case Statement 58-year-old female was admitted to our hospital because of isolated proteinuria. She was pointed out hypertension and no proteinuria at health checkup in 2005. She suffered from gross hematuria from 1st September, 2007 for one week. She frequented F medical center because of proteinuria at health checkup on 28th September, 2007. Urinalysis revealed proteinuria (2+) and occult blood (). Urinary excretion of protein was 1.7?g/day. Urinary cytology showed class I. She was referred, then admitted to our hospital to evaluate proteinuria on 28th January, 2008. Physical examination on admission revealed blood pressure of 148/96?mmHg, regular pulse rate of 64 beats/min, and no systemic edema. Laboratory tests showed the following results: blood urea nitrogen 16.5?mg/dL, serum creatinine 0.91?mg/dL, total protein MADH9 7.6?g/dL, serum albumin 4.6?g/dL, total cholesterol 242?mg/dL, hemoglobin 13.4?g/dL, white blood cell count 3700/ em /em L, and platelets count 203000/ em /em L. Serological test showed C-reactive protein 0.03?mg/dL, unfavorable for hepatitis B surface antigen, unfavorable for hepatitis C computer virus antibody, C3 114?mg/dL, C4 104?mg/dL, CH50 60?U/mL, and antinuclear antibody 40. Urinalysis showed proteinuria of 1 1.35?g/day without hematuria and cylinduria but with sediments of many transitional cells per high-power field and 0 to 3 leukocytes per high-power field. GNE-4997 Urinary chemistry was as follows: N-acetyl- em GNE-4997 /em -D-glucosaminidase 6.5?U/L and em /em 2-microglobulin 237? em /em g/L. Creatinine clearance was 103.0?L/day. Urinary cytology showed class V, suggesting urothelial carcinoma. Chest X-ray examination was found to be normal. Abdominal echography showed right-sided unilateral hydronephrosis (Physique 1(a)), and abdominal computed tomography with contrast media pointed out a mass in the right renal pelvis in association with pelvic dilatation and slight thinning of renal cortex (Physique 1(b)), strongly suggesting malignancy of renal pelvis. The right kidney was totally nephroureterectomized (Physique 2) on 29th February, 2008. Pathological diagnosis was urothelial carcinoma of renal pelvis (G2, INF em /em , pT1, rt-u0, ew0, ly0, v0) (data not shown). Renal histological examination revealed slightly ischemic switch of glomeruli without apparent glomerulopathy in association with tubular atrophy and interstitial fibrosis with mildly-to-moderately mononuclear cell infiltration in 60% of cortical areas (Physique 3(a)). Immunofluorescence study showed no deposition of immunoreactanct in the renal tissue and electron microscopy showed almost intact glomerulus without electron dense deposits (Physique 3(b)). Open in a separate window Physique 1 (a) Abdominal echography, showing right-sided unilateral hydronephrosis. (b) Abdominal computed tomography with contrast, showing an enhanced mass in the right renal pelvis (arrow) in association with pelvic dilatation and slight thinning of renal cortex. Open in a separate window Physique GNE-4997 2 Crosssection photograph of the removed right kidney specimen, showing a tumor of 9 6?cm in size in renal pelvis. Open in a separate window Physique 3 (a) Light microscopic photography, showing slightly ischemic switch of glomerulus, tubular atrophy, mononuclear cell infiltration, and interstitial fibrosis (mathon-trichrome staining, 200). (b) Electron micrograph of glomerulus, showing almost intact morphology without electron dense deposit. C: capillary lumen, M: mesangium. The patient discharged because that proteinuria disappeared within 6 days after the operation (Physique 4). Open in a separate window Physique 4 Clinical course of the patient. 3. Conversation It is well known that malignancy sometimes associates nephrotic syndrome [1, 2]. Malignancy-associated glomerular diseases may present most types of glomerulopathy [9]. Among them, membranous nephropathy by tumor-related antigen-antibody immune complexes in solid tumors is usually most commonly encountered [1]. Malignancy is also associated with nonnephrotic level proteinuria, however; cause of proteinuria GNE-4997 is not obvious because that histological examination of them is rare [3]. Hemmingsen et al. analyzed.