Differences in CT features of peritoneal carcinomatosis, sarcomatosis, and lymphomatosis: retrospective analysis of 122 cases at a tertiary cancer institution.

AIMS: To study the differences in the imaging features of spread from the three cancer cell lines, namely epithelial, sarcomatoid, and lymphoid, resulting in peritoneal carcinomatosis, peritoneal sarcomatosis, and peritoneal lymphomatosis, respectively.

MATERIALS AND METHODS: In this institutional review board-approved Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study, an electronic radiology database was searched to identify patients with peritoneal tumour spread who underwent CT imaging at Dana-Farber Cancer Institute, a tertiary cancer institution, between January 2011 and December 2012. Out of 1214 patients with possible peritoneal tumour spread on the radiology reports, 122 patients were included with histopathologically confirmed peritoneal disease (50 randomly selected patients with peritoneal carcinomatosis and sarcomatosis each, and all 22 patients with lymphomatosis). Two blinded, fellowship-trained radiologists in consensus reviewed the CT images in random order and recorded the imaging findings of peritoneal tumour spread. The statistical analysis was performed in two steps: the first comparing incidence of various features in each group and the second step was a pairwise analysis between each cohort.

RESULTS: Peritoneal carcinomatosis more frequently had ascites, peritoneal thickening, and omental cake (all p ≤ 0.001). Measurable nodules were less common in peritoneal carcinomatosis (p < 0.001), and when present, were ill-defined and had an irregular outline (p ≤ 0.002). Peritoneal sarcomatosis more often had discrete nodules that were well defined and had a smooth outline and less frequently had ascites, peritoneal thickening, omental caking, serosal implants, and lymphadenopathy (all p ≤ 0.005). Peritoneal lymphomatosis frequently involved the omentum and mesentery, and often had associated lymphadenopathy and splenomegaly (all p ≤ 0.002).

CONCLUSION: Peritoneal carcinomatosis, sarcomatosis, and lymphomatosis have distinctive patterns on imaging, which can help the radiologists to differentiate between them.