Rectal bleeding combined with the presence of a rectal mass has been traditionally associated with the presence of malignant disease. Cap polyposis is a relatively young and still undefined rare entity which mainly involves the rectosigmoid. It is characterized by the presence of inflammatory polyps. In this case report, we present a patient who was diagnosed with a solitary cap polyp of the rectum during the investigation of a bleeding rectal mass. The patient's age and the absence of family history were not in favor of malignancy, despite the strong initial clinical impression. After confirmation of the diagnosis, the patient underwent a snare excision and remains asymptomatic. Cap polyposis, although rare, should be suspected and, when diagnosed, should be treated according to location, number of polyps and severity of symptoms.

Background and Aims Kidney biopsy is the gold standard for establishing the diagnosis of ANCA-associated glomerulonephritis (GN). Previous studies have validated the prognostic significance of histopathological classification for the development of end stage renal disease (ESRD). We sought to evaluate the prognostic value of the EUVAS histopathological classification in terms of renal and overall survival (OS) in a single center retrospective cohort study. Method Forty-six consecutive patients (mean age 69, range; 29-84 years) with biopsy-proven ANCA-associated GN diagnosed at our hospital between January 2003 and January 2019 were included in the study. All biopsies had ≥10 glomeruli and were reviewed by two independent pathologists blinded to clinical data. Renal morphology was classified as sclerotic (if ≥50% globally sclerotic glomeruli), focal (if ≥50% normal glomeruli), crescentic (if ≥50% crescents with cellular component) and mixed. Probabilities of renal and overall survival were estimated using Kaplan-Meier method. Cumulative incidence function for ESRD was estimated using death as competing risk. Results Three biopsies were classified as focal (6%), twenty-nine as crescentic (63%), ten as mixed (22%) and four as sclerotic (9%). With a median follow-up of 39 months the 3-year probability of renal survival was 100% for the focal class, 66,37% for the crescentic class, 64% for the mixed class and 50% for the sclerotic class (p>0.05). Other parameters associated with increased probability of ESRD were interstitial fibrosis (IF) and eGFR at time of diagnosis. IF of ≥40% at diagnosis was associated with high incidence of ESRD, while IF of 20-40% and <20% had significantly lower incidence of ESRD (100% vs 34.2% vs 17.6%, p=0.014). Half (50%) of the patients with eGFR<15ml/min at diagnosis developed ESRD at 36 months compared to only 8% of the patients with eGFR≥15ml/min (p=0.024) at diagnosis. Median overall survival for the entire cohort reached 128 months (95% CI; 35-221). Twelve patients died at median time of 19,5 months (range; 3-129) after diagnosis. Three patients died before developing ESRD and nine patients developed ESRD prior to death. Leading cause of death was sepsis (8/12). Other causes included sudden death (n=2), malignancy (n=1) and intestinal obstruction (n=1). In terms of histopathological classification, OS at 3 years was 100% (95% CI; N/A) for the focal class, 73.5% (95% CI; 57-94.8) for the crescentic class, 100% (95% CI; N/A) for the mixed class and 37,5% (95% CI; 83,9-100) for the sclerotic class (p>0.05). Conclusion Our results suggest that the focal class has the best and the sclerotic the worst outcome, while both crescentic and mixed subtype are of intermediate risk. Although our results did not reach statistical significance, due to primarily the small number of patients included, the incidence of ESRD and the probability of renal survival in each histopathological subtype in our cohort are comparable to those reported by larger studies. Thus, the EUVAS histological classification of ANCA-associated glomerulonephritis appears to be a useful predictor of renal outcome at the time of diagnosis. As previously reported, no significant prognostic difference was observed between the crescentic and mixed subtype. Thus, this classification system should be optimized by inclusion of other histological characteristics, such as the specific percentage of normal glomeruli, tubular atrophy and interstitial fibrosis. These characteristics may prove useful in highlighting significant differences between mixed and crescentic classes.

Background and Aims Renal transplantation is considered the most effective and less costly modality of renal replacement therapy in patients with end stage renal disease. The disparity between kidney allografts and recipients has led to a global effort to increase the pool of kidney donors. Accordingly, fibromuscular dysplasia (FMD) is no longer considered an absolute contraindication for kidney donation. The incidence of FMD is about 2.3%-5.8% in potential kidney donors. There are few cases in the literature where renal artery stenosis in allografts with known pre-transplantation FMD became worse after transplantation, indicating the importance of a proper follow up in the recipients. This is a case of a living kidney donor with no history of hypertension, proteinuria or elevated serum creatinine, whose intra-arterial digital subtraction angiography revealed FMD lesions in the left renal artery. Method Case report Results A 54-year-old Caucasian female with medical history of hypothyroidism took the decision to offer her kidney to her 37-year-old son who was diagnosed with end-stage renal disease five years ago secondary to diabetes mellitus type I. She had no history for diabetes, hypertension and renal disease. Her vital signs on admission were heart rate of 78 beats/min and blood pressure of 130/70 mmHg. Urinalysis, biochemical profile and serological evaluations were all within normal ranges. Blood urea was 36 mg/dL and serum creatinine was 0.6 mg/dL (eGFR 97ml/min/1.73m2). The abdominal ultrasound and renogram with Tc-99m DTPA showed no remarkable findings. On intra-arterial digital subtraction angiography an abnormal succession of dilatations and multifocal stenoses of the left renal artery, characteristic of medial FMD, was found. The right renal artery was normal. Apart from a dysfunctional permanent left femoral catheter, the patient had no other vascular access for hemodialysis because of Superior Vena Cava syndrome, so he needed urgent transplantation. Taking all of these into consideration, the patient was offered renal transplantation as the best option. A left open donor nephrectomy was performed; the renal artery was divided distal to the stenotic dysplastic area. The allograft was placed at the right iliac fossa of the recipient with arterial and venous anastomosis to the extrarenal iliac vessels. Post-operatively, the recipient had a delayed graft function lasted 13 days. On renal artery Doppler in the allograft we found increased resistance index (RI) that gradually normalized without any intervention. An immunosuppressive regiment of tacrolimus, mycophenolate and prednisone was administered according to our center protocol. At discharge serum creatinine was 1.7 mg/dL (eGFR: 50ml/min/1.73m2). At the year follow-up, the donor was normotensive and had near normal renal function (Cr:1.3mg/dL, eGFR: 70ml/min/1.73m2). The recipient has a well-controlled blood pressure receiving two antihypertensive drugs and maintains a satisfactory renal function. Conclusion Few cases with FMD in renal allografts from living and deceased donors have been described. In a review of 4 studies the authors concluded that the outcome of transplantation with allografts from living donors with medial FMD was satisfactory and these allografts could be used to increase the donor pool. Furthermore, it is strongly recommended to have a thorough pre-transplantation check of the donor as well as a close monitoring of both the donor and recipient after transplantation. This case shows that allografts harvested from carefully selected donors with renal arterial FMD can be successfully used, particularly in urgent conditions. Detailed pre-tranplantation imaging of donor’s renal arteries, selection of the appropriate screening method, as well as close monitoring of both donor and recipient for early interventions after transplantation is of paramount importance.