Coronary artery aneurysms are rare complications of autosomal dominant polycystic kidney disease (ADPKD), and their pathogenesis remains poorly understood. We report an autopsy case of a 64-year-old ADPKD patient with an asymptomatic, large (4 cm in diameter) saccular aneurysm arising from the left circumflex (LCX) branch of the coronary artery with only mild atherosclerotic changes. Autopsy also revealed small, focal defects of media with or without microaneurysm formation in the LCX, mesenteric and renal arteries, and a fibromuscular dysplasia-like lesion with microaneurysm in the common iliac artery. Since polycystin-1 and -2 are expressed in arterial smooth-muscle cells, these findings imply that abnormal polycystin expression in ADPKD initially causes the focal medial defects, some of which might later progress to microaneurysms and then overt aneurysms. To the best of our knowledge, this is the first description of the pathologic findings of an ADPKD-associated coronary aneurysm and its probable precursor lesions in arteries.

Sunitinib is an orally administered inhibitor of tyrosine kinase targeting vascular endothelial growth factor receptors (VEGFRs) and has become essential for treating metastatic renal cell carcinoma. Recently, several cases have been reported which showed proteinuria and kidney dysfunction during anti-VEGF therapy. Although previous reports indicated that this side effect is reversible, it is not well understood. We report here the case of a 52-year-old man who presented with hypertension, nephrotic syndrome, and renal dysfunction during sunitinib treatment. Sunitinib was discontinued, but renal function recovery was limited. A renal biopsy was performed because sunitinib was again required and pathological examination was needed. The renal biopsy showed exacerbation of diabetic nephropathy. After medical treatment, the patient's blood pressure was controlled and serum creatinine level decreased. We considered that the patient could tolerate sunitinib at a minimum effective dose, 25 mg/day. Previous reports suggest that all anti-VEGF drugs may share a common risk for developing renal adverse events, such as thrombotic microangiopathy. Sunitinib should not be restarted if thrombotic microangiopathy is observed. The present case suggests that renal biopsy would be recommended when treatment options and prognosis might be influenced by the actual histological diagnosis.Keywords Renal cell carcinoma Á Tyrosine kinase inhibitor Á Thrombotic microangiopathy Á Diabetic nephropathy Á Renal biopsy Case presentationDr. Oya (urologist, conference chairperson) Good evening, ladies and gentlemen, welcome to the conference. Today we would like to review a metastatic renal cell carcinoma (mRCC) case who was treated with sunitinib. In this case, renal dysfunction and proteinuria appeared in particular after several cycles of treatment and persisted as a problem until discontinuation of sunitinib. First, we will have a presentation of the patient, and then discuss the clinical assessment, treatment, and specific pathology. Dr. Mizuno (urologist)The patient is a 49-year-old Japanese man with a history of type 2 diabetes mellitus for 4 years, who underwent left