What are the modes of spread to the peritoneum?
Intraperitoneal seeding & direct invasion are most common, and is the dominant method of spread of abdominal malignancies. Hematogenous dissemination is also seen in breast and lung cancer and melanoma. Lymphatic dissemination is rare.
What are the treatment option for peritoneal metastatic disease?
Peritoneal metastases per se are not locally treated, although systemic treatment may have some effect. Complications do however frequently require treatment for palliation: bowel obstruction: bypass enterostomies may be required; malignant ascites: repeated ascitic drainage.
Peritoneal fluid is present which outlines multiple areas of peritoneal nodular thickening (blue arrows). In addition the omentum to the left of the midline appears stranded with soft tissue nodules (red arrows).
The pleura on the left has a similar appearances (green arrows), and multiple mixed sclerotic / lytic lesions are seen the largest involving the right pedicle and adjacent vertebral body of T12 (yellow dotted line).
Bilateral breast prosthesis are noted (*).