Perineal recurrence presenting as a cutaneous lesion after intersphincteric abdominoperineal resection for low rectal cancer: a case report with implications for surgical planning and postoperative surveillance
TL;DR
This case highlights the importance of margin-oriented surgical planning and suggests that careful perineal inspection may be considered during postoperative surveillance, although rare, perineal recurrence can occur after rectal cancer surgery.
Abstract
A 77-year-old man with low rectal cancer (cT3N0M0) underwent laparoscopic intersphincteric abdominoperineal resection. During the transanal phase, the Lone Star® Retractor System was used, and the anterior wall of the anal canal was slightly injured. Histopathological examination showed T3N0M0 disease with the closest circumferential resection margin measuring 0.6 mm. Computed tomography (CT) performed 3 months after surgery demonstrated a presacral soft-tissue lesion with an enhancing nodule, which remained stable over time and was considered a postoperative change. At 28 months after surgery, perineal bleeding led to the discovery of a friable 3-cm cutaneous tumor in the perineal region, which was locally resected. Histopathology revealed moderately differentiated tubular adenocarcinoma with extensive necrosis. Immunohistochemistry showed cytokeratin (CK) 7 negativity, CK20 positivity, and caudal-type homeobox 2 positivity, consistent with rectal cancer origin. Because the excision margin of the recurrent lesion was negative and CT showed no definite continuity with the presacral lesion, the tumor was regarded as perineal cutaneous recurrence. Although rare, perineal recurrence can occur after rectal cancer surgery. This case highlights the importance of margin-oriented surgical planning and suggests that careful perineal inspection may be considered during postoperative surveillance.