Abstract
Suspected case of malignant lymphoma (small cell type) of the lung is reported. A coin lesion in the right upper lobe of an asymptomatic 31 year-old male was detected in a mass survey. Partial resection of the right upper lobe was carried out under a diagnosis of pseudolymphoma of the lung based on the transbronchial lung biopsy finding. Histologically the mass was composed of small lymphocytes and small numbers of another inflammarory cells. Though tumor cells were mainly small lymphocytes, rather monotonous and homogenous infiltration and location of the tumor cells around the mass were consistent with malignant lymphoma (small cell type). Immunohistochemical staining of tumor cells was not successful. We collected primary lymphoproliferative disorders of the lung reported in Japan, such as pseudolymphoma, lymphid interstitial pneumonia and primary malignant lymphoma (small cell type), including primary pulmonary macroglobulinemia (lympho-plasma cell type). Differentiation between benign and malignant cases based on the criteria of Colby is discussed.
