CT findings of BALTOMA

To review the CT findings of BALTOMA, a low-grade malignant lymphoma originating from bronchus-associated lymphoid tissue (BALT).

The CT findings, symptoms, and clinical courses of BALTOMA in five patients were reviewed. The specimens obtained at operation were investigated, and the pathological findings were compared with the CT findings.

There were no symptoms in four patients and normal laboratory data in all patients. One patient who complained of general malaise underwent surgery under suspicion of lung carcinoma. Four patients were observed from 4 months to 7 years and 1 month under the diagnosis of organizing pneumonia or chronic inflammatory processes. On CT images a localized lesion was seen in four cases, while multiple lesions were seen in one case. Attenuation of the lesions was between 39.15 and 60 HU on nonenhanced CT. Lesions were homogeneously enhanced by contrast material. The margins of the lesion were clearly demarcated by interlobular septa in one portion and were unclear in the other portion in all cases. Air bronchograms were seen in four cases. CT angiogram signs were seen in three of four cases in which contrast study was performed. There was no lymphadenopathy, pleural changes, or invasion to other organs. The pathological investigation revealed small lymphocytes that showed monoclonality in all cases.

Awareness of the CT findings of BALTOMA can help to avoid misinterpreting BALTOMA as chronic inflammation and/or lung carcinoma. When a slowly progressive chronic pneumonia is being followed up, transbronchial lung biopsy and immunoglobulin staining of lymphocytes should be recommended for the correct diagnosis.