The management of retrorectal tumours: tertiary centre retrospective study

Abstract

Aim: Tumours of the retrorectal space are uncommon, pathologically heterogeneous, and difficult to diagnose, with ongoing controversy over their surgical management. The aim of this study was to evaluate the surgical management of a consecutive series of patients who had undergone excision of primary retrorectal tumours (PRRTs) at a tertiary referral centre.

Method: Patients were identified from a prospectively maintained database between 1 March 2001 and 1 August 2021. Electronic patient records were reviewed for demographics, preoperative imaging, operative details, histology, and follow-up. A chi-squared test was used to assess the statistical significance of findings.

Results: A total of 144 patients were included in the study. Of these, 103 patients were female (71.5 per cent), 46 patients (31.9 per cent) presented incidentally, and 99 of the patients had tumours located below S3 (68.7 per cent). Overall, 76 patients underwent a transperineal approach (52.7 per cent) with the most common findings of a benign tailgut cyst occurring in 59 (40.9 per cent) of cases. Preoperative MRI predicted urovascular and pelvic sidewall involvement assessed intraoperatively with a sensitivity of 83.3 and 90 per cent and a specificity of 98.1 and 98 per cent respectively. Risk of malignancy in solid tumours was 31.4 versus 8.8 per cent in cystic tumours (relative risk 3.5, 95 per cent c.i. 1.6 to 7.6, P < 0.001). Major complications (Clavien-Dindo grade III and above) occurred in eight patients (5.6 per cent) and all-cause long-term mortality was 4.8 per cent (seven patients).

Discussion: PRRTs can be safely excised with minimal complications in specialized centres by surgical teams with the relevant expertise. This study questions the conservative management of cystic tumours and given the risk of solid tumour malignancy, supports surgical management.

Fig. 1

MRI of the pelvis and rectum demonstrates a large well defined cystic lesion filling the entire lower pelvis with intermediate-to-high signal, likely solid components antero-inferiorly but no invasive margin. Histopathology showed benign tailgut cyst with previous haemorrhage.

Fig. 2

Transformation of a tailgut cyst from a cystic appearance (a) to a mixed heterogenous component marked with arrows (b) on surveillance MRI axial images.

Fig. 3

a Displays an intra-abdominal image of initial laparoscopic dissection around a retrorectal Schwannoma. b Depicts excision of chordoma that required a distal sacrectomy via a perineal approach with the patient in a prone jack-knife position.