The association of malignant lymphoma with subsequent development of a solitary chest wall mass is uncommon. Diffuse large B-cell lymphoma is a subcategory of non-Hodgkins lymphoma that commonly affects the stomach, thyroid, parotid glands, and lungs. There is a defined association between preexisting inflammation and the development of these lymphomas. It is also well known to have a predilection to disseminate to extranodal sites in a noncontiguous manner and has been previously reported to affect the chest wall in less than 100 cases. We present the case of an enlarging chest wall mass with an associated lymphomatous pleural effusion found to be an unusual presentation of diffuse large B-cell lymphoma.