Abstract
A 43-year-old female, diagnosed as having Hashimoto's Thyroiditis previously, was admitted to our hospital for further examination of the stomach following the gastric cancer mass survey. Endoscopic study showed an irregular-shaped erosion with purpurae on the anterior wall of the lower gastric body. Histological studies of the biopsy specimen revealed malignant lymphoma. Chest X-ray, abdominal ultrasonography, and whole body computer tomography revealed no lymphadenopathy. We, therefore, diagnosed as primary gastric malignant lymphoma and carried out total gastrectomy. Histological and immunohistochemical studies of the resected specimen showed that the lymphoma was of diffuse, medium-cell type with helper/inducer T cell phenotype. Primary solitary gastric T-cell malignant lymphoma is rare, and only ten cases have been reported in Japan. It is also interesting to consider the association between malignant lymphoma and Hashimoto's thyroiditis, because both diseases are associated with immunological abnormalities.
