Is CIS of the ureter responsible for skipped lymph node metastasis? A case report.

A case of skipped lesion of lymph node metastasis of left ureteral tumour with concurrent carcinoma in situ in the affected ureter is presented. Postoperatively, lymph node metastasis was de novo detected in the left retrocrural and renal hilar regions on CT scan, although only the obturator lymph node was histologically metastatic among the regional lymph nodes completely dissected. The possible explanations of this rare metastatic mode are discussed.