Role of 18F-FDG PET/CT in patients affected by pulmonary primary lymphoma

Abstract

BackgroundPrimary pulmonary lymphoma (PPL) is defined as clonal abnormal hyperplasia of lung parenchyma or bronchial lymphoid tissue originating from bronchial mucosal tissue. However, PPL is rare, which accounts for approximately 3-4% of extraneurotic lymphomas and 0.5-1% of all primary tumors in the lung. Owing to the lack of any typical clinical symptoms and radiological features, it is challenging to accurately diagnose PPL, which affects its clinical management and prognosis. Considering this, herein, we aim to raise awareness of this disease and help physicians understand the role of 18F-FDG PET/CT in the diagnosis of PPL.MethodA retrospective analysis was performed on the clinical and 18F-FDG PET/CT imaging data of 19 patients diagnosed with PPL by biopsy pathology at our hospital from April 2014 to December 2021.ResultsOf the 19 PPL patients, 15 patients showed clinical symptoms with the most common being fever and cough. In addition, there were 4 cases that had no clinical symptoms, and all of them were MALT lymphoma. In fact, 16 patients were misdiagnosed as lobar pneumonia, lung cancer, tuberculosis, and diffuse interstitial inflammation, representing a misdiagnosis rate of 84.2%. Also, 73.7% were MALT lymphomas, representing the most common pathological pattern, along with 3 DLBCL and 2 T-cell lymphomas. With reguard to CT signs, the air-bronchial sign was found to be the most common, followed by the halo sign and the collapsed leaf sign. On the basis of the predominant radiologic features, lesions were categorized as pneumonic consolidation, nodular/mass type, diffuse interstitial type, and mixed type. The average SUVmax of lesions was 7.23 ± 4.75, the ratio of SUVmax (lesion/liver) was 3.46 ± 2.25, and the ratio of SUVmax (lesion/mediastinal blood pool) was found to be 5.25 ± 3.27. Of interest, the different pathological types of PPL showed different values of 18F-FDG uptake. The 18F-FDG uptake of DLCBL was the most prominent with a SUVmax of 15.33 ± 6.30 and was higher than that of MALT lymphoma with a SUVmax of 5.74 ± 2.65. There appeared similarity in 18F-FDG uptake between MALT lymphoma and T-cell lymphoma. For the SUVmax of lesion, we found statistical significance between MALT lymphoma and DLCBL (P value<0.001). In addition, we also found statistical significance (P value < 0.05) in SUVmax of lesions between pneumonic consolidation type and nodal/mass type, I stage, and other stages.ConclusionsOn 18F-FDG PET/CT images, certain features of PPL morphology and metabolism can be identified that may contribute to a better understanding of this disease. In addition, 18F-FDG PET/CT whole-body imaging has the potential to refine the staging of PPL. Most importantly, functional 18F-FDG PET/CT imaging can readily reflect tumor cell activity, thus allowing for the selection of an optimal biopsy site.

Clinical imaging of primary pulmonary nucleoprotein of the testis carcinoma

“…It is difficult to distinguish NUT from other pulmonary tumors based solely on PET/CT findings. Previous literature reported that the SUV max of pulmonary squamous cell carcinoma ranged from 3.1 to 30.2 ( 6 ), the SUV max of lung adenocarcinoma ranged from 2.2 to 18.1 ( 53 ), the SUV max of pulmonary primary lymphoma ranged from 2.58 to 22.6 ( 54 ), the SUV max of small cell lung cancer ranged from 3.3 to 29.9 ( 55 ). And there is no obvious difference compared with the data for lung NUT we summarized above.…”

Evaluation of CT features for differentiating consolidation pattern of pulmonary MALT lymphoma from pneumonic-type lung adenocarcinoma

“…Consistent with other studies, a defining feature of MALT was the absence of significant mediastinal or hilar adenopathy. In the opinion of most researchers, MALT is essentially extranodal lymphomas according to the diagnostic criteria, rarely involving hilar and mediastinal lymph nodes ( 29 ). In addition, pleural invasion, as indicated by pleural effusion was less frequent in C-MALT than P-LADC.…”

Revising the Landscape of Cytokine-Induced Killer Cell Therapy in Lung Cancer: Focus on Immune Checkpoint Inhibitors

“…Owing to the extensive genomic sequencing approaches, both mutation-related and pathologically variable molecular features of lung cancers have been elaborated. In fact, an accumulation of such datasets has also helped to successfully and effectively define (diagnostically) diverse lung cancer types ranging from non-small cell lung cancer (NSCLC: squamous cell carcinoma and non-squamous cell carcinoma) to small cell lung cancer (SCLC: limited stage SCLC and extensive stage SCLC) [ 1 , 2 , 3 , 4 ]. However, it is still unclear how lung cancer cells can escape the immune system, posing a serious challenge to treatment resistance.…”