PEDUNCULATED GASTRIC SIGNET RING CELL CARCINOMA

Signet ring cell carcinoma (SRCC) is characterized by poor ductal formation and a diffuse progression pattern and generally presents as a depressed lesion in the majority of cases. We describe here an extremely rare case of gastric SRCC that presented as a pedunculated lesion. We hypothesize that the major factor responsible for the elevation of this lesion was proliferation of signet ring cells that did not lose their mutual connections. Among the two cases of early elevated‐type gastric SRCC that have been reported in the literature, this is the first case of pedunculated intramucosal SRCC. Pathological examination revealed no cancer cells in the basal part of the elevated lesion. The cellular morphology was consistent with SRCC, although the ductal structure was well preserved and more similar to well‐differentiated adenocarcinoma. Endoscopic examination showed a smooth‐surfaced lesion with no depressed region around the basal part of the elevated lesion. Because these findings differ significantly from previous reports of elevated SRCC, this report provides further insight into the nature of SRCC.