Algorithms for the surgical management of benign and malignant presacral tumors

Abstract

Presacral (or retrorectal) tumors are rare tumors which arise in the space between the mesorectum and the sacrum. This space contains tissues derived from all three germ cell layers and from which presacral tumors may arise. Presacral tumors can be broadly categorized as congenital or acquired, and benign or malignant, and morphologically they may be cystic, solid or heterogeneous. This group of tumors are often asymptomatic and may be identified incidentally on clinical examination or pelvic imaging. Magnetic resonance imaging (MRI) is the gold standard imaging modality as it can accurately demonstrate the relationship between the tumor and adjacent structures and helps to delineate between benign and malignant lesions. PET/CT can be useful when assessing malignant and indeterminate lesions in order to identify aggressive pathology and exclude metastatic disease. Radiologically-guided percutaneous biopsy of malignant or indeterminate tumors can be performed safely in order to obtain a histological diagnosis and determine whether there is a role for adjuvant therapies. Surgery is the mainstay of treatment of presacral tumors. Benign lesions can be monitored with regular MRI, particularly smaller lesions which are asymptomatic. If resection is required, benign lesions can often be “shelled out” with preservation of adjacent structures and therefore function, whereas malignant tumors generally require radical excision with wide margins and sacrifice of involved pelvic organs or soft tissues, bone and neurovascular structures.