Purpose: To investigate the etiologies of the sandwich sign other than lymphoma.
Method: The images of 34 patients with sonographic sandwich sign over a 5-year period were retrospectively reviewed. The etiology was based on the pathologic report of mesenteric lymph nodes, or the presence of extensive metastatic disease in case of known advanced primary cancer or disappearance of the sign after specific treatments.
Results: Malignancy accounted for the majority of cases (91%), and was divided into non-Hodgkin's lymphoma (50%) and metastatic carcinomas (41%). Mycobacterium tuberculosis infection was diagnosed in a previously healthy patient, and 2 patients with acquired immunodeficiency syndrome had Mycobacterium avium-complex infection. The sandwich sign was 1 of the initial presentations in 11 cases with newly diagnosed malignancies, including 6 cases of non-Hodgkin's lymphoma and 5 cases of metastatic carcinomas.
Conclusion: Metastatic carcinomas, M. avium-complex, and M. tuberculosis infection may produce the sandwich sign. Searching for etiologies other than lymphoma is important in patients presenting with the sandwich sign.