Finding
    Chest radiograph shows multiple, ill-defined, patchy opacities in both lung fields. Enhanced CT scans show several patchy opacities with air-bronchogram and homogeneous enhancement in the both lungs. There are several lymph nodes in the para-tracheal area and the anterior mediastinum, which are homogeneously enhanced. On lung-setting CT scan, the outer borders of the opacities are shaggy.

Brief Discussion
    Lymphomatous involvement of the lung can be classified into the four categories: primary lymphoma of the lung, recurrent or secondary lymphoma, lymphoma in the patients with posttansplantation lymphoproliferative disorders (PTLD), and AIDS-related lymphoma (ALD). Primary pulmonary lymphoma is usually non-Hodgkin’s in type (low-grade B-cell type is common). The frequency of lymphoma arising in the lung is estimated to be less than 1% of all lymphomas. Although thoracic Hodgkin’s disease typically presents with lymphadenopathy, a rare form of pulmonary Hodgkin’s disease is restricted to the pulmonary parenchyma at presentation. Primary pulmonary lymphoma is diagnosed with the following strict criteria: the lung or bronchus or both are involved, without evidence of mediastinal adenopathy or a mass on chest radiographs; extrathoracic lymphoma was not diagnosed previously; no evidence of extrathoracic lymphoma or lymphatic leukemia at the time that primary lymphoma of the lung was diagnosed, as evaluated on the basis of the results of physical examination, complete blood counts, abdominal sonography or CT scan or lymphography, and bone marrow aspiration or biopsy or both; and the disease was not present outside the thorax for at least 3 months after diagnosis.
    Most common radiologic appearance of primary non-Hodgkin’s lymphoma of the lung is an area of opacification with poorly defined margins and an air-bronchogram. Less common radiographic patterns of primary lymphoma of the lung include nodules, diffuse bilateral air space consolidation, and segmental or lobar atelectasis. Non-Hodgkin’s involvement of the lung can take the form of so-called mucosa-associated lymphoid tissue (MALT) or the closely related bronchus-associated lymphoid tissue (BALT). In MALT and BALT, lymphomatous masses develop in multiple extranodal mucosal sites throughout the lung, giving rise to multiple pulmonary masses in imaging studies. Pleural involvement is rare. Primary Hodgkin’s disease most commonly presents as single or multiple nodules with an upper lobe predominance. The nodules frequently cavitate.
    The incidence of secondary involvement of the lung at initial presentation is 12 % of patients with Hodgkin’s disease and 4% of patient with non-Hodgkin’s lymphoma. In Hodgkin’s disease, pulmonary involvement is almost always associated with radiographically evident hilar and mediastinal lymphadenopathy. Non-Hodgkin’s lymphoma may involve the mediastinal nodes and lungs or may be limited to the lungs. On chest radiographs, secondary pulmonary lymphoma may present with various pattern: thickening of bronchovascular bundles and interlobular septae (41%), discrete pulmonary nodules (39%), areas of consolidation (14%), and disseminated micronodules (6%). Lymphadenopathy and pleural effusion are also commonly present. Other manifestations include cavitated masses and endobronchial masses. Most common CT features of secondary pulmonary lymphoma are masses or masslike areas of consolidation larger than 1cm and nodules smaller than 1cm.