[A histopathologic study of the disseminated peritoneal metastasis of gastric cancer]

A total of 117 cases of gastric cancer with peritoneal metastasis was subjected to gross observation and histopathologic examination of metastatic lesion to clarify whether the metastases change in morphology along with time. When the patterns of gross morphology were classified by the time of ascertainment, the disseminated or scattered nodule type occupied 94% in the time of first surgery, which were reduced to 74% in relapse or recurrence. Postmortem examined cases showed very high incidences of the diffuse infiltration type. In 12 cases receiving laparotomy twice, the nodule type was outstanding in the first surgery and in recurrence, while the infiltration type was noted in relapse and at autopsy. These are indicative of chronologic transition of gross appearances of peritoneal metastases along with the development of cancer. Histopathologic observations suggested that when poorly differentiated adenocarcinoma (especially of the scirrhous and intermediate type) was metastasized intraperitoneally, the metastases were of the nodule type first, and then gradually proceeded into the infiltration type. When well differentiated adenocarcinoma or poorly differentiated adenocarcinoma of the medullary type were metastasized, they formed nodular type metastasis, however, poorly differentiated adenocarcinoma of the scirrhous type recognized as the morphologic subtype of carcinoma in the primary lesion proliferated later. These metastases might be infiltrate proliferated superiorly, which have presumably produced time changes in their gross appearance.