Synchronous double primary lymphosarcoma and adenosarcoma (collision tumor) of the stomach with cancer-to-cancer metastasis

An unusual instance of synchronous double primary lymphosarcoma and adenocarcinoma (collision tumor) of the stomach with metastasis of the adenocarcinoma to regional lymphosarcomatous lymph nodes (cancer-to-cancer metastasis) is described. This combination of tumors occurred in a 72-year-old Negro woman with periodic symptoms of peptic ulceration of several years' duration. Although the incidence of double cancers of the stomach approximates 2.15% in various series, associated cancer-to-cancer metastasis of the same tumors is considered rare. Only one similar case was encountered in the literature.