Lymphomatoid granulomatosis: CT and FDG-PET findings

Abstract

Objective: Lymphomatoid granulomatosis (LG) is a rare, aggressive extranodal Epstein-Barr virus (EBV)-positive B-cell lymphoproliferative disease. The purpose of our study was to analyze the CT and fluorodeoxyglucose positron emission tomography (FDG-PET) findings of pulmonary LG.

Materials and methods: Between 2000 and 2009, four patients with pathologically proven pulmonary LG and chest CT were identified. Two of these patients also had FDG-PET. Imaging features of LG on CT and PET were reviewed.

Results: Pulmonary nodules or masses with peribronchovascular, subpleural, and lower lung zonal preponderance were present in all patients. Central low attenuation (4 of 4 patients), ground-glass halo (3 of 4 patients), and peripheral enhancement (4 of 4 patients) were observed in these nodules and masses. An air-bronchogram and cavitation were seen in three of four patients. FDG-PET scans demonstrated avid FDG uptake in the pulmonary nodules and masses.

Conclusion: Pulmonary LG presents with nodules and masses with a lymphatic distribution, as would be expected for a lymphoproliferative disease. However, central low attenuation, ground-glass halo and peripheral enhancement of the nodules/masses are likely related to the angioinvasive nature of this disease. Peripheral enhancement and ground-glass halo, in particular, are valuable characteristic not previously reported that can help radiologists suggest the diagnosis of pulmonary LG.

Keywords: Air-bronchogram sign; Cavitation; Halo sign; Lymphomatoid granulomatosis; Pulmonary masses; Pulmonary nodules.

Fig. 1

Chest CT and FDG-PET images of patient 1. A. Axial pre-contrast CT image demonstrates peribronchovascular pulmonary nodules/mass and small left pleural effusion. B. Axial post-contrast CT image shows peripheral enhancement and central low attenuation of nodules/mass. C. Axial CT image in lung window shows subtle ground-glass halo of two left lower lobe nodules as well as ground-glass opacity in anterolateral aspect of right lower lobe mass. Air-bronchogram is noted in lateral left lower lobe nodule. Small peribronchovascular nodules are noted in right lower lobe. D. Axial FDG-PET image demonstrates peripheral FDG uptake in pulmonary nodules/mass.

Fig. 2

Chest CT and FDG-PET images of patient 2. A, B. Axial CT images in lung windows demonstrate peribronchovascular nodules with subtle ground-glass halos. Left lower lobe nodule shows central cavitation and internal air-bronchogram. C. Axial CT image in soft tissue window demonstrates peripheral enhancement and central low attenuation of nodules. D. Axial non-contrast CT performed two weeks after images A-C shows rapid enlargement of nodules. This also confirms that peripheral enhancement seen on prior CT was not due to intrinsic hyperdensity. E. Axial images from FDG-PET demonstrates peripheral FDG uptake within pulmonary nodules.

Fig. 3

Contrast-enhanced chest CT of patient 3. A. Axial image in soft tissue window demonstrates multiple pulmonary nodules and masses with peripheral enhancement and central low attenuation. Mass in right lower lobe is cavitary. B. Axial image in lung window demonstrates presence of air-bronchogram and ground-glass halo (arrows) of some nodules. Nodules and masses are distributed along bronchovascular bundle and in subpleural region.

Fig. 4

Pathology of lymphomatoid granulomatosis of patient 3. A. Initial biopsy showed grade 1 histology, with only isolated large neoplastic cells (arrows) in predominant background of small lymphocytes (Hematoxylin & Eosin staining). B, C. Sparse neoplastic cells are positive for B-cell marker CD20 (B, immunostain for CD20) and for Epstein-Barr virus (EBV) (arrow) (C, Epstein-Barr encoded RNA in situ hybridization). D. In subsequent biopsy, EBV-positive neoplastic cells are more frequent, concurrent with progression to grade 3 histology (Epstein-Barr encoded RNA in situ hybridization).

Fig. 5

Contrast-enhanced chest CT of patient 4. Axial image demonstrates solitary nodule in posterior costophrenic right lower lobe with peripheral enhancement and central low attenuation.