Abdominoperineal Resection for Unexpected Distal Intramural Spreading of Rectal Cancer

In rectal cancer, distal intramural spread may sometimes occur, but a maximum extent of distal spread of > 6 cm is very rare.

A 65-year-old Japanese male with an advanced rectal cancer tumor with para-aortic lymph node metastasis was admitted. We performed a low anterior resection with lymphadenectomy, but the intraoperative frozen-section analysis of margins revealed malignant cell positivity; we, therefore, performed an abdominoperineal resection. Pathological findings showed that the maximum extent of distal spread was 6 cm. After 12 courses of FOLFOX4 as adjuvant chemotherapy, abdominal computed tomography revealed whole lymph node metastases, including Virchow's node. Though FOLFIRI + panitumumab was started, he was not eligible for additional chemotherapy after 10 cycles.

An intraoperative frozen pathology examination was helpful for the additional resection, when unexpected distal spreading had occurred in rectal cancer. The evidence of a distal negative margin should not be underestimated.