Pulmonary lymphoma is a lymphoproliferative disease involving the lung parenchyma. Primary pulmonary lymphoma (PPL) is rare, comprising <1% of all pulmonary neoplasms — the most common type is MALT (mucosa-associated lymphoid tissue) lymphoma. Secondary pulmonary involvement is more common in Hodgkin and non-Hodgkin lymphoma. Radiologically, it may present as consolidation, mass, nodules, or peribronchial/perivascular thickening. Air bronchograms and homogeneous enhancement are characteristic.
Age Range
20-70
Peak Age
50
Gender
Male predominant
Prevalence
Uncommon
Primary pulmonary lymphoma originates from bronchial mucosa-associated lymphoid tissue (BALT) — chronic antigenic stimulation (autoimmune, infection) leads to BALT hyperplasia and neoplastic transformation. MALT lymphoma is a low-grade B-cell lymphoma that spreads from the peribronchial/perivascular region. Lymphoma cells infiltrate the bronchial wall and peribronchial interstitium but preserve alveolar architecture — hence air bronchograms are preserved (patent bronchi within consolidation). Homogeneous enhancement reflects uniform tumor cell distribution — necrosis is rare because lymphoma cells do not disrupt vascular architecture. In secondary involvement, hematogenous or lymphatic spread produces multiple nodular or peribronchial/perivascular patterns. High-grade lymphomas like DLBCL show more aggressive patterns — necrosis and cavitation may occur.
Bronchial lumens remain patent within consolidation or mass areas, preserving air bronchograms. This finding results from lymphoma cells filling alveoli while preserving bronchial structure — 'lepidic' growth pattern. While bronchi may become obstructed in infection, preserved bronchial patency is characteristic of lymphoma.
Preserved air bronchograms within areas of consolidation. Lymphoma cells infiltrate peribronchial interstitium and alveoli but leave the bronchial lumen patent. This finding is highly characteristic of pulmonary lymphoma and important in differential diagnosis from infectious consolidation.
Report Sentence
An area of consolidation measuring __ is noted in the right/left lung with preserved air bronchograms; should be evaluated with initial consideration of pulmonary lymphoma in clinical context.
Diffuse or focal thickening along peribronchial/perivascular bundles. This pattern reflects spread of lymphoma cells along peribronchial lymphatic channels and requires differential diagnosis from lymphangitic carcinomatosis.
Report Sentence
Thickening along peribronchial/perivascular bundles is noted and should be evaluated with initial consideration of lymphoproliferative disease.
Homogeneous enhancement of mass or consolidation on contrast-enhanced CT. Necrosis and cavitation are rare in low-grade lymphoma. Heterogeneous enhancement and necrosis may be seen in high-grade lymphoma (DLBCL).
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The mass/consolidation demonstrates homogeneous enhancement on contrast-enhanced series; no necrosis is identified; may be consistent with low-grade lymphoma.
FDG uptake in pulmonary lesion(s) on PET-CT. DLBCL and Hodgkin lymphoma show high FDG avidity (SUVmax usually >10). MALT lymphoma may show low to moderate FDG uptake or may be FDG-negative. Concurrent mediastinal/hilar/extranodal FDG-avid lymphadenopathy supports secondary involvement.
Report Sentence
FDG uptake with SUVmax __ is noted in the pulmonary lesion(s) on PET-CT; biopsy is recommended with initial consideration of lymphoproliferative disease.
Mediastinal and/or hilar lymphadenopathy is common in secondary pulmonary involvement. Symmetric mediastinal LAP is typical in Hodgkin lymphoma. Asymmetric or conglomerate LAP may be seen in non-Hodgkin lymphoma. LAP is usually absent or minimal in primary MALT lymphoma.
Report Sentence
Multiple pathologically enlarged lymph nodes are noted in the mediastinal/hilar region, consistent with lymphoproliferative disease.
Criteria
Low-grade B-cell lymphoma, BALT-derived, extranodal (no or minimal nodal involvement), indolent course, may remain stable for extended periods
Distinct Features
Most common type of primary pulmonary lymphoma (70-90%). Presents as consolidation or ground-glass opacity. PET-CT may show low uptake or be negative. 5-year survival >90%. Treatment: surgery or chemotherapy/rituximab.
Criteria
High-grade B-cell lymphoma, aggressive course, rapidly growing mass, necrosis may occur, PET-CT high FDG uptake
Distinct Features
10-20% of primary pulmonary lymphoma. Presents as large mass or consolidation. Cavitation and pleural effusion may accompany. Treatment: R-CHOP chemotherapy. Prognosis worse than MALT.
Criteria
Pulmonary involvement in known Hodgkin or non-Hodgkin lymphoma, accompanied by mediastinal/hilar LAP, multiple nodules or peribronchial/perivascular infiltration
Distinct Features
Much more common than primary pulmonary involvement. Direct extension (mediastinal mass → lung) in Hodgkin, hematogenous spread more common in non-Hodgkin. Multiple nodules, may be bilateral. Treatment targets systemic disease.
Distinguishing Feature
Adenocarcinoma usually presents as a spiculated nodule/mass with heterogeneous enhancement. In lymphoma, air bronchograms are preserved within consolidation, enhancement is homogeneous, and peribronchial/perivascular distribution is typical.
Distinguishing Feature
Mucinous adenocarcinoma may show consolidation and air bronchograms (similar to lymphoma). However, low attenuation (due to mucin content), CT angiogram sign, and multilobar spread suggest mucinous adenocarcinoma. In lymphoma, homogeneous enhancement and peribronchial/perivascular pattern predominate.
Distinguishing Feature
Organizing pneumonia shows peripheral consolidations, migratory pattern, and reversed halo (atoll sign). Responds rapidly to corticosteroid therapy. In lymphoma, consolidation is more stable or slowly growing, does not show migration, and response is to chemotherapy.
Distinguishing Feature
Metastasis usually presents as multiple well-defined nodules without expected air bronchograms. Consolidation pattern, peribronchial/perivascular thickening, and preserved air bronchograms distinguish lymphoma.
Urgency
urgentManagement
medicalBiopsy
NeededFollow-up
3-monthBiopsy is mandatory for pulmonary lymphoma diagnosis — bronchoscopic biopsy, CT-guided percutaneous biopsy, or surgical biopsy. In MALT lymphoma, treatment is surgical resection (if localized) or chemotherapy/rituximab (if disseminated). R-CHOP chemotherapy is standard in DLBCL. Treatment targets systemic disease in secondary involvement. PET-CT is critical for staging and treatment response assessment. Long-term follow-up is needed in MALT lymphoma as late recurrence may occur. Autoimmune diseases (Sjogren syndrome, Hashimoto) are risk factors for MALT lymphoma.
Primary MALT lymphoma has excellent prognosis. Prognosis in secondary lymphoma depends on stage and histology. Chemotherapy and/or radiotherapy is the mainstay of treatment. Definitive diagnosis requires biopsy.