Patterns of peritoneal spread of tumor in the abdomen and pelvis

Abstract

The spread of tumor in the peritoneum can be understood, although it is a complex organ. A study of its embryology, anatomy and function is of clear benefit. It is formed from a network of folds, reflections, and potential spaces produced by the visceral and parietal peritoneum. These folds and reflections begin as a dorsal and ventral mesentery, supporting the primitive gut in early embryologic development. The dorsal mesentery connects the stomach and other organs to the posterior abdominal wall, while the ventral mesentery connects the stomach to the ventral abdominal wall. As the embryo develops, there is further organ growth, elongation, cavitation and rotation. The dorsal and ventral mesentery also develops along with the viscera, forming ligaments, mesenteries, omenta and potential spaces from the resulting reflections and folds. These ligaments, mesenteries, and omenta, support and nurture the organs of the peritoneum, providing a highway for arteries, veins, nerves and lymphatics. The potential spaces created from these folds and reflections of the visceral and parietal peritoneum are also important to realize. For example, the transverse mesocolon divides the peritoneal cavity into a supramesocolic and inframesocolic space in the abdomen and paravesicular spaces within the pelvis. The falciform ligament is well known in the supramesocolic space, dividing it further into a left and right compartment. Knowledge of the peritoneal vascular anatomy is beneficial in locating the spaces and ligaments about the peritoneum. For example, identifying the left gastric artery or vein will lead to the gastrohepatic ligament, which is part of the supramesocolic space. Besides serving a life sustaining role, the multiple compartments, ligaments, mesenteries and omenta within the peritoneum can also facilitate the spread of disease. Tumors can spread directly from one organ to another, seed metastatic deposits in the peritoneal cavity, and travel through the lymphatic or hematogenous route to invade other organs in the peritoneum.

Image-guided Biopsy of Mesenteric, Omental, and Peritoneal Disease

“…In general, malignancies spread via direct extension, intraperitoneal seeding, lymphatic dissemination, or hematogenous dispersion. 6,7 All of these pathways are in effect within the peritoneum and adjacent spaces, but special consideration should be given to peritoneal, subperitoneal, and transperitoneal pathways, which are comparatively unique. 4 Peritoneal dissemination involves confined spread within the peritoneal cavity and may manifest as tumor implants, abscesses, ascites, or pneumoperitoneum.…”

“…For example, disease may be confined to either the supramesocolic or inframesocolic spaces, which are separated by the transverse mesocolon, or further into the right or left divisions of the supramesocolic space, which are divided by the falciform ligament. 7 Subperitoneal dissemination refers to the spread throughout the continuous subperitoneal space. Given its extensive and interconnected nature, disease may extend in many directions including into the retroperitoneum, mesentery, peritoneal ligaments, and/ or under the peritoneal surface of organs.…”

Cytoreductive Surgery and Peritonectomy Procedures

“…Hematogenous route: This route is employed by both intra and extra-abdominal tumors and PM arising from breast cancer, lung cancer and melanoma spread by this route. [11] Basic Principles CRS comprises of peritonectomy procedures and visceral resections. The goal is to remove all macroscopic disease leaving no residual disease or for some pathologies like pseudomyxoma peritonei or peritoneal mesothelioma, disease that is not greater than 2.5 mm in size.…”

Role of Imaging in Peritoneal Surface Malignancies

“…Hematogenous route: This route of spread is seen in both intra and extra-abdominal tumors and PM arising from breast cancer, lung cancer and melanoma spread by this route. [58] Imaging Features and Patterns of Involvement of Peritoneal Surfaces Perihepatic Spaces The tumour deposits on the surface of the liver as well as along all its ligaments (ligamentum teres, ligamentum venosum, and falicform ligament), fissures and fossae (umbilical fissue and gall bladder fossa) and the spaces around the liver. Tumor from the right paracolic gutter spreads to the right subphrenic space and from the gall bladder fossa to the Morrison's pouch.…”