A 60-year-old man presented with flank pain while passing a kidney stone. CT of the abdomen and pelvis showed left and right renal masses in a horseshoe kidney.
He subsequently underwent partial nephrectomy with removal of the left mass. By gross examination, there was a 0.9 x 0.7 x 0.5 cm well circumscribed mass with yellow-tan cut surface, located within 0.3 cm of the parenchymal resection margin.
![]() |
Mira Lotfalla, M.B., B.Ch. Resident, Anatomic Pathology Mayo Clinic |
![]() |
Loren Herrera Hernandez, M.D. Consultant, Anatomic Pathology Mayo Clinic Assistant Professor of Laboratory Medicine and Pathology Mayo Clinic College of Medicine |