An ontogenetic approach to gynecologic malignancies.

unlabelledOntogenetic anatomy is the mapping of body compartments established during early embryologic development, particularly well demarcated in the adult pelvis. Traditional cancer surgery is based on wide tumour excision with a safe margin, whereas the ontogenetic theory of local tumour spread claims that local dissemination is facilitated in the ontogenetic compartment of origin, but suppressed at its borders in the early stages of cancer development. Optimal local control of cancer is achieved by whole compartment resection with intact margins following ontogenetic "planes". The principles embodied in this hypothesis are most convincingly supported by the results of the implementation of total mesorectal excision in rectal cancer, and more recently, by innovative surgical approaches to gynaecologic malignancies. The high resolution contrast of MR, accurately delineating pelvic fascial compartments, makes it the best imaging modality for gynaecologic cancer surgery planning following these principles, but requires interpretation of imaging anatomy from a different perspective. TEACHING POINTS: • Ontogenetic anatomy refers to mapping of embryologically determined body compartments. • Ontogenetic theory claims tumour growth is not isometrical, but rather compartment permissive. • Ontogenetic principles are highly supported by the outcome results of total mesorectal excision. • Innovative gynaecologic cancer surgery approaches based on ontogenetic theory show promising results.