[A case of transitional cell carcinoma and milk of calcium in a pyelocalyceal diverticulum].

A 66-year-old man presented with right flank pain and macroscopic hematuria. Abdominal radiographs and computed tomography revealed a right pyelocalyceal diverticulum with milk of calcium and a soft tissue mass inside it. Other examinations, including positive urine cytology and negative random bladder biopsies, suggested a malignant tumor of the pyelocalyceal diverticulum. The patient underwent right nephroureterectomy. Histopathological examination revealed grade 3 transitional cell carcinoma. This is the first case of transitional cell carcinoma and milk of calcium coexisting in the same pyelocalyceal diverticulum.