Imaging the peritoneum for malignant processes

Peritoneal malignancy: anatomy, pathophysiology and an update on modern day imaging

With increasing subspecialised experience in radical cytoreductive surgery and intra-abdominal chemotherapy for peritoneal malignancy, outcomes have improved significantly in selected patients. The surgery and the treatment regimens are radical and therefore correct patient selection is critical. The radiologist plays a central role in this process by estimating, as precisely as possible, the pre-treatment disease burden. Because of the nature of the disease process, accurate staging is not an easy task. Tumour deposits may be very small and in locations where they are very difficult to detect. It must be acknowledged that no form of modern day imaging has the capability of detecting the smallest peritoneal nodules, which may only be visible to direct inspection or histopathological evaluation. Nonetheless, it behoves the radiologist to be as exact and precise as possible in the reporting of this disease process. This is both to select patients who are likely to benefit from radical treatment, and just as importantly, to identify patients who are unlikely to achieve adequate cytoreductive outcomes. In this review, we outline the patterns of spread of disease and the anatomic basis for this, as well as the essential aspects of reporting abdominal studies in this patient group. We provide an evidence-based update on the relative strengths and limitations of our available multimodality imaging techniques namely CT, MRI and positron emission tomography/CT.

CT findings of lymphoma with peritoneal, omental and mesenteric involvement: peritoneal lymphomatosis

PURPOSE

We aimed to describe computed tomography (CT) findings in patients with peritoneal, omental and mesenteric lymphoma involvement.

MATERIALS AND METHODS

We searched our archive retrospectively to find out patients with peritoneal, omental and mesenteric lymphoma involvement. We found 16 patients with non-Hodgkin lymphoma meeting these criteria. CT studies of these patients were reevaluated for the presence of peritoneal involvement, ascites, omental mass, organomegaly, retroperitoneal lymphadenopathy, bowel wall thickening and other associated findings.

RESULTS

There were 14 males and 2 females with peritoneal and/or mesenteric and omental lymphoma involvement. Mean age was 39 (range 4-76). Subgroups of non-Hodgkin lymphoma were diffuse large B-cell lymphoma (n=11), small cell lymphocytic lymphoma (n=2), small cleaved cell lymphoma (n=1), T-cell lymphoma (n=1) and Burkitt's lymphoma (n=1). Peritoneal involvement was seen in 15 patients (93.8%) in the form of linear (n=12) and nodular (n=3) thickening. Ascites was seen in 12 (75%) patients. Omental and mesenteric masses were present in 10 (66.6%) and 10 (66.6%) patients, respectively. Bowel wall thickening, retroperitoneal lymphadenopathy and hepatosplenomegaly were also common and observed in 10, 10 and 11 patients, respectively. Solid organ involvement in the form of liver and splenic lesions was seen in 9 (56%) patients.

CONCLUSION

Peritoneal involvement can be seen in many subtypes of lymphoma and most frequently in diffuse large B-cell lymphoma. Peritoneal lymphomatosis can mimic peritoneal carcinomatosis and should be included in the differential diagnosis list in patients with ascites, hepatosplenic lesions and unidentified cause of peritoneal thickening on CT in a male patient.