Lymphoid tumors of the gastro-intestinal tract are by no means rare and have been treated at length in the literature of the past three decades. The majority have been included in the more or less general term of sarcoma, but while such a classification is no doubt correct, the lymphoid tumors form a group in themselves and should be considered separately. The histogenesis of this group is still marked by obscurity and has been the basis for much controversial opinion. The nomenclature is confused, and owing to a lack of knowledge of the histogenesis of these tumors, they have run the gamut of pathologic classification. More important than a suitable nomenclature is the recognition of a malignant process. Some of the tumors undoubtedly are malignant. They metastasize and recur after excision. Others pursue the course of a benign growth, and it is frequently impossible to differentiate the two types microscopically.