Pulmonary adenocarcinoma with massive lymphocyte infiltration: report of three cases.

We report on three cases of pulmonary adenocarcinoma with lymphoid stroma. In these cases the lesions were small pulmonary adenocarcinomas, less than 2 cm in diameter, and histologically diagnosed as poorly or moderately differentiated adenocarcinomas. Histologically, the tumors were characterized by a small number of cancer cells and numerous infiltrating lymphoid cells, especially CD8 positive T-cell lymphocytes. No Epstein-Barr virus (EBV) genomes were demonstrated by in situ hybridization in the tumor cells of any of the tumors. Lobectomy and regional lymph node dissection were performed and intrapulmonary and mediastinal lymph node metastases were demonstrated in one of these cases (pT4N0M0, pT1N2M0 and pT1N0M0). Two patients are alive and the other died of pneumonia 26 months after the operation. None of the patients experienced recurrence of carcinoma. This unique type of adenocarcinoma characterized by massive lymphocyte infiltration could be referred to as "pulmonary adenocarcinoma with lymphoid stroma".