Primary Lymphoproliferative Lung Diseases: Imaging and Multidisciplinary Approach

Abstract

Lymphoproliferative lung diseases are a heterogeneous group of disorders characterized by primary or secondary involvement of the lung. Primary pulmonary lymphomas are the most common type, representing 0.5-1% of all primary malignancies of the lung. The radiological presentation is often heterogeneous and non-specific: consolidations, masses, and nodules are the most common findings, followed by ground-glass opacities and interstitial involvement, more common in secondary lung lymphomas. These findings usually show a prevalent perilymphatic spread along bronchovascular bundles, without a prevalence in the upper or lower lung lobes. An ancillary sign, such as a "halo sign", "reverse halo sign", air bronchogram, or CT angiogram sign, may be present and can help rule out a differential diagnosis. Since a wide spectrum of pulmonary parenchymal diseases may mimic lymphoma, a correct clinical evaluation and a multidisciplinary approach are mandatory. In this sense, despite High-Resolution Computer Tomography (HRCT) representing the gold standard, a tissue sample is needed for a certain and definitive diagnosis. Cryobiopsy is a relatively new technique that permits the obtaining of a larger amount of tissue without significant artifacts, and is less invasive and more precise than surgical biopsy.

Keywords: HRCT; diagnostic imaging; lung; lung neoplasm; lymphoma.

Figure 1

Chest CT of a primary MALT lymphoma expressed as consolidations with air bronchogram (A) and angiogram sign (B—red arrow). Images in (C,D) show a DLBCL primary lymphoma manifested as a necrotic mass: chest radiograph in (C) shows an opacity in the right lower lobe; the chest CT study in (D) confirms the presence of a mass within the angiogram (red arrow) and air bronchogram signs.

Figure 2

Lung nodules in the medium lobe (A). The PET scan in (B) shows a high captation of 18FDG, a high suspicion for primary lung cancer. Biopsy revealed primary MALT lymphoma of the lung.

Figure 3

Images in (A–C) demonstrate the presence of diffuse rounded nodules in the peribronchovascular bundles; also, perilobular “atoll sign” is present, showing an “OP-like” pattern (OP: organizing pneumonia).

Figure 4

A case of DLBCL with a mixed pattern made of bilateral nodules (in A–C), interstitial involvement, and consolidations (in (B)).

Figure 5

Diffuse interstitial lung involvement in MALT lymphoma. HRCT scans in (A–C) show diffuse thickening of the interlobular septa, together with peri-lobular ground-glass opacities and small confluent consolidations.