Malignant lymphoma mimics miliary tuberculosis by diffuse micronodular radiographic findings

This case reports rare findings on computed tomography of a manifestation of malignant lymphoma, in which diffuse lung shadows appeared as miliary nodules distributed throughout the lungs bilaterally. The patient had a history of surgical treatment of rectal cancer and had received chemotherapy for suspicious liver metastasis. At her current presentation for evaluation suspected miliary tuberculosis on chest radiography, subsequent liver biopsy revealed a mass infiltration of atypical lymphocytes, which was diagnosed as follicular lymphoma. The miliary tuberculosis was suspected more than neoplastic lesions, such as metastatic rectal cancer or malignant lymphoma. Despite repeated bacteriologic tests of various samples, including sputum, urine, bronchial secretion, peripheral blood, bone marrow aspiration, and gastric lavage, all results were negative for mycobacterium tuberculosis. Finally, multiple, small, mass lesions of lymphocytes were demonstrated in the lung obtained from video-assisted thoracic surgery, and a diagnosis of follicular lymphoma was given. The final interpretations of liver mass and military lung lesions were tumor involvement by the follicular lymphoma. This radiologic findings of multiple miliary opacities throughout the whole lungs confused definite diagnosis because these images were remarkably similar with miliary tuberculous. This case reminds us to consider a wide variety of differential diagnoses even we assumed to be familiar with radiographic imaging at first glance.