The clinical features of overlap syndrome (ANCA-associated crescentic glomerulonephritis [AACGN] and immune complex-mediated glomerulonephritis) are similar to those of AACGN alone.

The overlap syndromes of anti-neutrophil cytoplasmic antibodies (ANCA)-associated crescentic glomerulonephritis (AACGN) and variants of immune complex medicated glomerulopathy (ICMGN) have been reported. But very few have compared AACGN alone with the overlap syndromes (AACGN plus ICMGN). The aim of this retrospective study was to make that comparison, following serum creatinine (sCr) to determine whether the two groups (AACGN-only group versus overlap group) would behave differently over time. We identified 14 cases with dual diagnoses of AACGN and various ICMGN in the overlap group. Data were collected and compared with 15 randomly selected AACGN-only cases over the similar period of time. The overlap syndrome represented 0.35% of our overall biopsies (14/4049). All 14 patients were ANCA positive and had crescentic formation. The percentage of crescents in the biopsies ranged from 10 to 78%. ICMGN included the following: membranoproliferative glomerulonephritis, post-infectious glomerulonephritis, membranous glomerulopathies, idiopathic mesangial proliferative glomerulonephritis, lupus nephritis, and IgA nephropathy. With the exception one biopsy revealing lupus nephritis class III, most of the ICMGN were mild. When compared to the AACGN-only group, there were no significant differences in clinical and histologic indices including age, percent of crescents, and sCr (on biopsy days, and over the follow-up periods), although the numbers of follow-up cases were limited over time. Our findings suggest that AACGN was the dominant disease process in the majority of overlap syndromes between AACGN and ICMGN, similar to the clinical processes of AACGN-only disease, therefore, the AACGN in overlap syndrome cases should be the main target for clinical management.

Acquired von Willebrand Disease Secondary to Clear Cell Renal Cell Carcinoma.

Background: Acquired von Willebrand disease (AvWD) is a rare and often underdiagnosed disease that typically is associated with lymphoproliferative, cardiovascular disease, and myeloproliferative disease. It is challenging to diagnose as it requires a hemostatic challenge to present itself. Case Presentation: This is a 46-year-old male with a history of multiple sclerosis complicated by neurogenic bladder who presented with intermittent gross painless hematuria. He underwent a gross hematuria workup. Cystoscopy demonstrated active bleeding from the right ureteral orifice. CT Urogram showed a filling defect in the right renal pelvis and endophytic 3 cm solid, enhancing left kidney mass. The patient underwent diagnostic cystourethroscopy, bilateral retrograde pyelogram demonstrating no filling defects bilaterally. Right ureteropyeloscopy demonstrated diffuse patchy erythema of the infrarenal collecting system with biopsies obtained. His postoperative course was complicated by gross hematuria requiring cystoscopy which demonstrated no upper tract bleeding and small pulsatile bleeding vessel in the bladder requiring cauterization. Hematology was consulted to rule out bleeding diathesis with workup demonstrating a von Willebrand deficiency (vWD). He had no family history of vWD and an AvWD was suspected. Hematologic workup was consistent with AvWD, type 2B vWD also known as a platelet-type von Willebrand disease. Renal pelvis biopsies were negative for pathology. Further investigation of the left renal mass confirmed a biopsy-proven clear cell renal cell carcinoma (ccRCC). He underwent a laparoscopic left radical nephrectomy with final pathology demonstrating pT1 ccRCC with negative margins. Postoperatively his repeat laboratories demonstrated normal factor VIII activity, ristocetin cofactor, and vWF antigen with normalized activated partial thromboplastin time. Follow-up imaging demonstrated no further evidence of disease supporting the hypothesis of a paraneoplastic syndrome from his ccRCC that caused an AvWD. Conclusion: This is the first case report to our knowledge of a paraneoplastic AvWD secondary to ccRCC. This should be on your differential when there is abnormal bleeding in the setting of renal masses.