Primary pulmonary lymphoma is a rare entity usually formed of B-type cells, usually low-grade and composed of mucosal- or bronchial-associated lymphoid tissue. High-grade primary pulmonary lymphomas usually occur in immunodeficient patients who mostly present with respiratory and nonspecific symptoms. A chest x-ray may show a pulmonary mass or atelectasis and pleural effusion. In such cases, the prognosis is worse than for low-grade pulmonary lymphomas; survival is 8 to 10 years and there is a higher probability of local progression or metastasis. We report the case of an immunocompetent 76-year-old patient who had a pulmonary mass with cavitation secondary to a large B-cell primary pulmonary lymphoma. After the fourth session of chemotherapy the pulmonary mass was reduced in size and an aspergilloma was seen to have developed in the residual cavity. A review of the literature revealed this case to be anecdotal as it is extremely infrequent for a primary pulmonary lymphoma to present in the form of a single mass with cavitation and with few symptoms.