Squamous cell carcinoma arising in a tailgut cyst: role of radiotherapy

Abstract

Tailgut cysts (TGCs) are rare tumours which can undergo malignant transformation. The gold standard of treatment is complete surgical excision. Multidisciplinary assessment is advisable in order to apply adjuvant treatment. Postoperative radiotherapy should be given in case of compromised surgical margins or other factors such as high histological grade or perineural and lymphovascular invasion. Here, we present a case of a squamous cell carcinoma arising from a retrorectal TGC treated with surgery and postoperative radiotherapy and review the main indications and techniques of this therapy.

Keywords: Pathology; Radiotherapy.

Figure 1

Sagittal and axial views of the diagnostic MRI showing the retrorectal cyst and their anatomical relations.

Figure 2

Diagram of retrorectal cyst and their anatomical relations. This figure was entirely illustrated by D Aldave, co-author of the article.

Figure 3

Gross appearance of the resection specimen: the lesion has been opened to show the cystic cavity and the solid indurated area in the wall.

Figure 4

Microscopic study: H&E stain and immunohistochemical study (CK5-6 and p63).

Figure 5

Planning target volume for radiotherapy in blue and organs to be spared: rectum (orange), bladder (yellow) and small intestine (brown).