Photodynamic therapy as salvage therapy for residual microscopic cancer after ultra-low anterior resection: A case report

Figure 1 Findings of colonoscopy and endoscopic ultrasonography during treatment. A: The colonoscopy revealed a 3 cm × 4 cm ulcerated mass in the rectum 4 cm from the anus before surgery; B: After surgery, there was a rectal mucosal inflammation change without residual tumour on colonoscopy; C: The patient underwent photodynamic therapy, a circular piece of mucosal tissue fell off the anus, but the anastomotic stenosis was observed at 5 cm from the anus; D and E: Five years after the operation, there was an intestinal canal stenosis without tumour on endoscopic ultrasonography.

Figure 2 Pathological changes in the patient with positive microscopic distal margins after photodynamic therapy. A and B: Postoperative histopathologic examination revealed that the tumour was a moderately differentiated rectal adenocarcinoma and a partial mucinous adenocarcinoma; the TNM stage was T2N0M0, with no cancer in the incision margin and no metastasis (0/4) to the lymph nodes. Unfortunately, cancer was detected on the lateral edge of the operated area; C and D: Five years after the operation, microscopic examination of a biopsy at the rectal anastomosis showed the formation of inflammatory necrotic lesions and the formation of ulcerative lesions in the inflammatory granulation tissue. No malignancy was found in multiple sections.