[Null-cell non-Hodgkin's lymphoma presenting with a mass in the chest wall after tuberculous pyothorax]

A 59-year-old male, who was treated with artificial pneumothorax for pulmonary tuberculosis 42 years previously, presented with a painful mass in the left lateral chest wall and lymph node swelling in the left neck. A chest CT-scan revealed a tumor shadow extending from the outer chest wall to the pleural cavity containing pus surrounded by calcified pleura. 67Ga scintigraphy showed accumulation of the radionuclide in the left lateral chest and left neck. Biopsy specimen obtained from both the chest tumor and cervical lymph node revealed diffuse large cell lymphoma. Immunostaining failed to demonstrate CD1, CD3, CD4, CD8, CD13, CD20, immunoglobulin, alpha, gamma, mu, delta, kappa and lambda chains, indicating null cell characteristics. Chemotherapy consisting of cyclophosphamide, doxorubicin, vincristine, prednisolone and bleomycin and irradiation resulted in a temporary decrease of the tumor and lymph nodes, but the patient died of pneumonia 14 months after the onset of disease. Since the levels of serum lactate dehydrogenase and immunosuppressive acidic protein varied in parallel to the disease activity, they appeared to be useful for the assessment of therapeutic effects during the clinical course. Approximately 100 cases of non-Hodgkin's lymphoma developing after tuberculous pyothorax have been reported in this country, among which the incidence of null cell type is exceedingly rare.