“…However, its diagnosis is always challenging because its radiologic features are undefined [ 4 , 5 , 7 , 8 ]. To our knowledge, few cases have been reported in the literature, and previous reports have only described non-specific computed tomography (CT) and ultrasonography (US) findings similar to non-tumorous appendicitis, without evaluating the histopathologic correlations of the imaging findings [ 4 , 5 , 7 , 8 ]. In this case report, we describe the US findings of primary signet-ring cell carcinoma of the appendix in relation to the tumor’s histopathological characteristics.…”