Pulmonary mucosa-associated lymphoid tissue lymphoma: 18F-FDG PET/CT and CT findings in 28 patients

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

Purpose

In clinical practice, the consolidation pattern of pulmonary mucosa-associated lymphoid tissue (C-MALT) was often misdiagnosed as pneumonic-type lung adenocarcinoma (P-LADC). However, the mainstay of treatment and prognosis of these two diseases are different. The purpose of this study was to distinguish C-MALT from P-LADC by pre-treatment chest computed tomography (CT) features.

Patients and methods

A total of 31 patients with C-MALT (15 men and 16 women; mean age, 61.1 ± 11.2 years) and 58 patients with P-LADC (34 men and 24 women; mean age, 68.6 ± 7.4 years) confirmed by pathology who underwent contrast-enhanced chest CT were retrospectively enrolled from September 2014 to February 2023. Detailed clinical and CT characteristics of the two groups were evaluated. Logistic regression analysis was used to assess the effectiveness of statistically significant variables in distinguishing C-MALT from P-LADC.

Results

The average age of C-MALT was younger than P-LADC patients (p<0.001). With regard to CT features, bronchiectasis within the consolidation was more common in the C-MALT group than the P-LADC group [83.87% (26 of 31) vs 20.69% (12 of 58), p<0.001]; whereas lymph nodes enlargement [75.86% (44 of 58) vs 9.68% (3 of 31), p<0.001] and pleural effusion [43.10% (25of 58) vs 19.35% (6 of 31), p=0.025] were more frequently observed in the P-LADC group than C-MALT group. The predictors with p<0.05 (age, bronchiectasis, lymph node enlargement, and pleural effusion) were used to construct a logistic regression model in discriminating C-MALT from P-LADC, the area under curve (AUC), positive predictive value (PPV), negative predictive value (NPV), specificity, sensitivity, and accuracy were 0.9555, 86.67%, 91.53%, 83.87%, 93.10%, and 89.89%, respectively.

Conclusion

C-MALT and P-LADC have differential clinical and CT features. An adequate understanding of these different characteristics can contribute to the early accurate diagnosis of C-MALT and provide an appropriate therapeutic strategy.

Radiological and pathological analysis of the galaxy sign in patients with pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma

BACKGROUND

Pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma sometimes presents as large pulmonary nodules composed of small nodular opacities (galaxy sign) on computed tomography (CT). The aim of this study was to assess the presence, usefulness, and pathological characteristics of the galaxy sign on CT of pulmonary MALT lymphoma.

METHODS

From January 2011 to December 2021, chest CTs of 43 patients with pulmonary MALT lymphoma were reviewed by two radiologists for the galaxy sign and various other findings. Interreader agreement to characterize the galaxy sign and factors associated in making a correct first impression on CT prior to pathological diagnosis were assessed. Resected specimens were reviewed by two pathologists, and the proportion of peripheral lymphoma infiltrates was compared between lesions with and without the galaxy sign.

RESULTS

Of 43 patients, 22 patients (44.2%) showed the galaxy sign (κ = 0.768, p < 0.0001). The galaxy sign (p = 0.010) was associated with making a correct first impression on CT prior to pathological diagnosis. On pathological examination, lesions showing the galaxy sign on CT demonstrated a significantly higher proportion of peripheral lymphoma infiltrates (p = 0.001).

CONCLUSION

The galaxy sign can be seen on CT of pulmonary MALT lymphoma with a higher proportion of peripheral lymphoma infiltrates and may be useful in making a correct diagnosis of pulmonary MALT lymphoma.

Software-based quantitative CT analysis to predict the growth trend of persistent nonsolid pulmonary nodules: a retrospective study

PURPOSE

Persistent nonsolid nodules (NSNs) usually exhibit an indolent course and may remain stable for several years; however, some NSNs grow quickly and require surgical excision. Therefore, identifying quantitative features capable of early discrimination between growing and nongrowing NSNs is becoming a crucial aspect of radiological analysis. The main purpose of this study was to evaluate the performance of an open-source software (ImageJ) to predict the future growth of NSNs detected in a Caucasian (Italian) population.

MATERIAL AND METHODS

We retrospectively selected 60 NSNs with an axial diameter of 6-30 mm scanned with the same acquisition-reconstruction parameters and the same computed tomography (CT) scanner. Software-based analysis was performed on thin-section CT images using ImageJ. For each NSNs, several quantitative features were extracted from the baseline CT images. The relationships of NSN growth with quantitative CT features and other categorical variables were analyzed using univariate and multivariable logistic regression analyses.

RESULTS

In multivariable analysis, only the skewness and linear mass density (LMD) were significantly associated with NSN growth, and the skewness was the strongest predictor of growth. In receiver operating characteristic curve analyses, the optimal cutoff values of skewness and LMD were 0.90 and 19.16 mg/mm, respectively. The two predictive models that included the skewness, with or without LMD, exhibited an excellent power for predicting NSN growth.

CONCLUSION

According to our results, NSNs with a skewness value > 0.90, specifically those with a LMD > 19.16 mg/mm, should require closer follow-up due to their higher growth potential, and higher risk of becoming an active cancer.

Development and validation of a CT-based radiomics model for differentiating pneumonia-like primary pulmonary lymphoma from infectious pneumonia: A multicenter study

BACKGROUND

Pneumonia-like primary pulmonary lymphoma (PPL) was commonly misdiagnosed as infectious pneumonia, leading to delayed treatment. The purpose of this study was to establish a computed tomography (CT)-based radiomics model to differentiate pneumonia-like PPL from infectious pneumonia.

METHODS

In this retrospective study, 79 patients with pneumonia-like PPL and 176 patients with infectious pneumonia from 12 medical centers were enrolled. Patients from center 1 to center 7 were assigned to the training or validation cohort, and the remaining patients from other centers were used as the external test cohort. Radiomics features were extracted from CT images. A three-step procedure was applied for radiomics feature selection and radiomics signature building, including the inter- and intra-class correlation coefficients (ICCs), a one-way analysis of variance (ANOVA), and least absolute shrinkage and selection operator (LASSO). Univariate and multivariate analyses were used to identify the significant clinicoradiological variables and construct a clinical factor model. Two radiologists reviewed the CT images for the external test set. Performance of the radiomics model, clinical factor model, and each radiologist were assessed by receiver operating characteristic, and area under the curve (AUC) was compared.

RESULTS

A total of 144 patients (44 with pneumonia-like PPL and 100 infectious pneumonia) were in the training cohort, 38 patients (12 with pneumonia-like PPL and 26 infectious pneumonia) were in the validation cohort, and 73 patients (23 with pneumonia-like PPL and 50 infectious pneumonia) were in the external test cohort. Twenty-three radiomics features were selected to build the radiomics model, which yielded AUCs of 0.95 (95% confidence interval [CI]: 0.94-0.99), 0.93 (95% CI: 0.85-0.98), and 0.94 (95% CI: 0.87-0.99) in the training, validation, and external test cohort, respectively. The AUCs for the two readers and clinical factor model were 0.74 (95% CI: 0.63-0.83), 0.72 (95% CI: 0.62-0.82), and 0.73 (95% CI: 0.62-0.84) in the external test cohort, respectively. The radiomics model outperformed both the readers' interpretation and clinical factor model ( P <0.05).

CONCLUSIONS

The CT-based radiomics model may provide an effective and non-invasive tool to differentiate pneumonia-like PPL from infectious pneumonia, which might provide assistance for clinicians in tailoring precise therapy.

Primary Lymphoproliferative Lung Diseases: Imaging and Multidisciplinary Approach

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.

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

Background

Primary 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.

Method

A 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.

Results

Of 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.

Conclusions

On 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.

With the Increasing Health Awareness: Clinical and Computed Tomography Findings in Primary Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma Lymphoma

OBJECTIVE

The objective of this study is to investigate the clinical manifestations, computed tomography (CT) findings, and prognosis of primary pulmonary mucosa-associated lymphoid tissue lymphoma (MALToma) with the improved health awareness nowadays.

METHODS

Clinical data and CT images of patients with pathologically confirmed MALToma from October 2012 to October 2021 were retrospectively analyzed.

RESULTS

Eighteen MALToma patients were included in the study (8 men and 10 women; mean age, 56.17 years; range, 33-73 years). Six men had a long-term history of smoking (>20 years). One patient had an autoimmune disease (Sjögren syndrome). Eight patients (44.44%) were asymptomatic, and 10 (55.56%) had mild chest or systemic symptoms. Most lesions (88.89%) were subpleural or located along the bronchovascular tree. According to the CT characteristics, the lesions were divided into 4 groups: nodular type (n = 8; 44.44%, including 5 solid nodules and 3 ground-glass nodules), mass type (n = 4, 22.22%), patch or consolidate type (n = 5, 27.78%), and mixed type (n = 1, 5.56%). Air bronchogram (11/18, 61.11%) and angiogram sign (8/16, 50%) were the most frequent CT findings and may help differential diagnosis. The patients were misdiagnosed with lung cancer (n = 11, 61.11%), inflammatory or chronic inflammatory disease (n = 4, 22.22%), bronchiectasis accompanied by infection (n = 1, 5.56%), diffuse interstitial lung disease (n = 1, 5.56%), and granuloma or tuberculosis (n = 1, 5.56%). The prognosis of all patients was favorable; 1 patient was lost to follow-up.

CONCLUSIONS

Nowadays, patients with MALToma are usually asymptomatic or paucisymptomatic. Nodular lesions, including ground-glass nodules, are the most common presentation. Mucosa-associated lymphoid tissue lymphoma is most likely misdiagnosed as lung cancer. Lesions located in the subpleural areas or along the bronchovascular tree and presenting with an air bronchogram or angiogram sign could indicate a MALToma diagnosis.

Is There a Role for [18F]FDG PET-CT in Staging MALT Lymphoma?

Simple Summary

MALT lymphoma represents a relatively rare lymphoma subtype that arises in different extranodal anatomic locations. In the current paper we summarize our experience in assessing disease extent and metabolic characteristics of MALT lymphomas with [¹⁸F]FDG PET-CT at staging, and aim to highlight the strengths and challenges this imaging modality poses. In our data, all extranodal lesions located in subcutaneous-tissue, lung and liver were detected on PET, while some of those located in other tissues (such as along the digestive tract) were not detected on PET. We also evaluated the predictive role of PET in these patients, and found that increased [¹⁸F]FDG-uptake in extranodal lesions was associated with worse disease progression.

Abstract

The role of ¹⁸F-fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography—computed tomography (PET-CT) in assessing mucosa-associated lymphoid tissue (MALT) lymphoma is debatable. We retrospectively explored the role of [¹⁸F]FDG PET-CT in staging and predicting progression-free-survival (PFS) of patients with newly-diagnosed MALT lymphoma. Sixty-six studies were included. The maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were documented in the “hottest” extranodal and nodal lesions. Extranodal lesions and accompanying nodal disease were detected on PET in 38/66 (57.6%) and 13/66 (19.7%) studies, respectively. Detection rate of extranodal lesions differed significantly between those located in tissues with high/heterogeneous (e.g., stomach) vs low/homogenous (e.g., subcutaneous-tissue, lung) physiologic [¹⁸F]FDG-uptake (40.4% vs. 100%, p < 0.01). Nodal lesions had significantly lower SUVmax, MTV and TLG compared with extrandodal lesions in the same patients. Detection and [¹⁸F]FDG-avidity of extranodal lesions were higher in patients with advanced, bulky disease and concomitant marrow/nodal involvement. Increased SUVmax of extranodal lesions predicted shorter PFS (HR 1.10, 95% CI 1.01–1.19, p = 0.02). Higher SUVmax and TLG showed trends towards shorter PFS in patients with localized disease. In conclusion, detection rate of extranodal MALT lymphoma lesions located in tissues with low/homogeneous physiologic [¹⁸F]FDG-uptake is excellent on [¹⁸F]FDG PET-CT. When detected, SUVmax of extranodal lesions may predict PFS.

Different CT imaging findings between histological subtypes in patients with primary thyroid lymphoma

PURPOSE

This study evaluates the differences in CT imaging findings between diffuse large B cell lymphoma (DLBCL) and mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid gland.

METHODS

This study included 18 patients with histopathologically confirmed primary thyroid lymphoma (nine with DLBCL and nine with MALT lymphoma). All patients underwent pretreatment CT imaging. We retrospectively reviewed all images and compared the imaging findings between the two pathologies.

RESULTS

The maximum diameter was significantly greater in DLBCL than in MALT lymphoma (67.7 ± 17.0 mm vs. 41.0 ± 27.2 mm, p < 0.01). Diffuse type (78% vs. 11%, p < 0.01), thickening of the isthmus (78% vs. 22%, p < 0.05), invasion of surrounding tissues (78% vs. 0%, p < 0.01), and regional lymphadenopathy (44% vs. 0%, p < 0.05) were more frequent in DLBCL than in MALT lymphoma. However, preserved peripheral thyroid tissue was more frequent in MALT lymphoma than in DLBCL (78% vs. 22%, p < 0.05).

CONCLUSIONS

The maximum diameter, morphological patterns (diffuse or nodular type), thickening of the isthmus, invasion of surrounding tissues, regional lymphadenopathy, and preserved peripheral thyroid tissue were useful CT imaging features in differentiating DLBCL from MALT lymphoma of the thyroid gland.

A case of primary hepatic extranodal marginal zone B-cell mucosa-associated lymphoid tissue (MALT) lymphoma treated by radiofrequency ablation (RFA), and a literature review

Primary hepatic mucosa-associated lymphoid tissue (MALT) lymphoma is an extremely rare liver malignancy that usually lacks characteristic imaging findings and which is often misdiagnosed. We report a 63-year-old woman diagnosed with primary hepatic extranodal marginal zone B-cell lymphoma, MALT type. The patient underwent needle biopsy and radiofrequency ablation (RFA), and showed no signs of relapse during the 12-month postoperative follow-up. This case stresses the rarity of primary hepatic MALT-type lymphoma and the unique and effective treatment for this patient. Our patient received RFA, which showed good efficacy and which provides a new option for the treatment of hepatic MALT lymphoma. We also present our findings from a systematic review to improve the current understanding of this disease.

Correlation between 18 F-FDG PET/CT semiquantitative parameters and Ki-67 expression in pulmonary mucosa-associated lymphoid tissue lymphoma

INTRODUCTION

This study aims to investigate the correlation between ¹⁸ F-Fluoro-d-glucose positron emission tomography/computed tomography (¹⁸ F-FDG PET/CT) semiquantitative parameters and Ki-67 expression in pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma.

METHODS

Twenty-eight patients with histologically confirmed pulmonary MALT lymphoma in 29 lesions who underwent ¹⁸ F-FDG PET/CT were retrospectively analysed. PET/CT images were analysed visually and semiquantitatively by measuring maximum standardized uptake value (SUV_max ), mean standardized uptake value (SUV_mean ), metabolic tumour volume (MTV) and total lesion glycolysis (TLG). The correlation between morphological pattern, tumour size, Ki-67 expression and PET/CT semiquantitative parameters were also analysed.

RESULTS

There were 16 male patients (57.1%) and 12 female patients (42.9%), and the mean age was 57.6 ± 9.7 years (range 43-73 years). Twenty-nine pulmonary lesions were identified in 28 patients: 12 (41.4%) presenting as consolidation, 9 (31.0%) as nodules, 5 (17.2%) as masses and 3 (10.3%) as ground glass opacities (GGOs). All of the 29 lesions were ¹⁸ F-FDG avid. SUV_max of the lesions was 4.4 ± 3.0 (range 1.1-15.3), SUV_mean was 2.8 ± 1.9 (range 0.8-10.3), MTV was 15.9 ± 17.6 (range 0.9-82.1) and TLG was 48.7 ± 56.6 (range 0.9-205.6). The PET/CT semiquantitative parameters were not correlated with morphological pattern of pulmonary MALT lymphoma, which were correlated significantly with tumour size and Ki-67 expression.

CONCLUSION

Pulmonary MALT lymphomas are ¹⁸ F-FDG avid, and ¹⁸ F-FDG PET/CT semiquantitative parameters (SUV_max , SUV_mean , MTV and TLG) are significantly correlated with tumour size and Ki-67 expression. ¹⁸ F-FDG PET/CT plays a potential role in identifying lung MALT lymphomas with higher proliferation and more aggressive behaviour in clinical practice.

Clinicopathological characteristics and prognostic factors of primary pulmonary lymphoma

Background

Primary pulmonary lymphoma (PPL) is a rare extranodal lymphoma originating from the lung, accounting for 0.5–1.0% of primary lung malignant tumors. Previous case reports or cohort studies included a limited sample size; therefore, the understanding of the disease remains inadequate, and clinical data regarding PPL are limited.

Methods

Patients with PPL diagnosed histologically and radiologically between January 2000 and December 2019 at our center were retrospectively analyzed.

Results

In total, 90 consecutive cases were included in this research. Forty-seven (52.2%) patients were female, and the median age was 54 years old. Non-Hodgkin’s lymphoma (PPNHL) was the most common type of PPL (71/90, 78.9%), and mucosa-associated lymphoid tissue (MALT) lymphoma was the most common pathological subtype of PPNHL (56.3%) followed by diffuse large B-cell lymphoma (DLBCL) (32.4%). Thirty-nine (43.3%) patients underwent surgical treatment, and the others received chemotherapy alone or combined with radiotherapy. The estimated 5-year overall survival (OS) rates of MALT lymphoma and non-MALT lymphoma were 68.9% and 65.9%, respectively. Univariate analysis of PPL showed that clinicopathological features that significantly correlated with worse OS were age over 60 years (P=0.006<0.05), elevated LDH (P=0.029<0.05) and β2-MG (P=0.048<0.05) levels, clinical stage II2E and greater (P=0.015<0.05), and nonsurgical treatment (P=0.046<0.05). Age (P=0.013<0.05) was an independent prognostic factor for the 5-year OS of patients through multivariate analysis.

Conclusions

Age over 60 years old, elevated LDH and β2-MG levels, clinical stage II2E disease or higher, and nonsurgical treatment were associated with poor prognosis in patients with PPL. Age can be used as a potential independent prognostic factor for PPL.

Pulmonary mucosa-associated lymphoid tissue lymphoma: CT findings and pathological basis

BACKGROUND

Pulmonary mucosa-associated lymphoid tissue lymphoma (MALToma) is the most frequent subset of primary pulmonary lymphoma. This study aimed to identify radiologic characteristics of pulmonary MALToma based on computed tomography (CT) observations and pathologic features, and further investigate its prognosis.

METHODS

Sixty-six patients (55.4 ± 10.9 years; 51.5% male) diagnosed as pulmonary MALToma by pathology were retrospectively enrolled. According to distributions and features of lesions shown on CT, patients were divided into three patterns, including single nodular/mass, multiple nodular/mass, and pneumonia-like consolidative.

RESULTS

Variety of the location and extent of the lymphomatous infiltration accounted for different characteristics demonstrated at CT. The pneumonia-like consolidative pattern was the most frequent pattern observed in 42 patients (63.6%), followed by single nodular/mass (21.2%) and multiple nodular/mass (15.2%). CT features included air bronchogram (72.7%), well-marginated halo sign (53.0%), coarse spiculate with different lengths (72.7%), angiogram sign (77.1% of 35 patients), peribronchovascular thickening (48.5%), irregular cavitation (16.7%) and pulmonary cyst (7.6%). The estimated 5-year cumulative overall survival rate of pulmonary MALToma was 100.0%.

CONCLUSIONS

Pulmonary MALToma demonstrates several characteristics at CT. Identification of the significant pulmonary abnormalities of this indolent disease entity might be helpful for early diagnosis and optimal treatment.

Primary Pulmonary B-Cell Lymphoma: A Review and Update

Simple Summary

The group of B-cell lymphomas primarily involving the lung encompasses different histological entities with distinct biological aspects, while sharing some clinical and radiological features related to their common anatomic site of occurrence. Recent molecular advances in the molecular genetics of these lesions have substantially improved of our understanding of the mechanisms of lymphomagenesis, adding novel information to histology in order to better characterize and manage these diseases. This review summarizes the available clinical, radiological, pathological, and molecular data on primary pulmonary B-cell lymphomas, discusses the mechanisms of lymphomagenesis, and highlights the role of a multi-disciplinary management in overcoming the diagnostic and therapeutic challenges in this setting.

Abstract

Primary pulmonary B-cell lymphomas (PP-BCLs) comprise a group of extranodal non-Hodgkin lymphomas of B-cell origin, which primarily affect the lung without evidence of extrapulmonary disease at the time of diagnosis and up to 3 months afterwards. Primary lymphoid proliferations of the lung are most often of B-cell lineage, and include three major entities with different clinical, morphological, and molecular features: primary pulmonary marginal zone lymphoma of mucosa-associated lymphoid tissue (PP-MZL, or MALT lymphoma), primary pulmonary diffuse large B cell lymphoma (PP-DLBCL), and lymphomatoid granulomatosis (LYG). Less common entities include primary effusion B-cell lymphoma (PEL) and intravascular large B cell lymphoma (IVLBCL). A proper workup requires a multidisciplinary approach, including radiologists, pneumologists, thoracic surgeons, pathologists, hemato-oncologists, and radiation oncologists, in order to achieve a correct diagnosis and risk assessment. Aim of this review is to analyze and outline the clinical and pathological features of the most frequent PP-BCLs, and to critically analyze the major issues in their diagnosis and management.

Clinical and radiological characteristics of patients with pulmonary marginal zone lymphoma: A single center analysis

Pulmonary marginal zone lymphoma (PMZL) is the most common non‐Hodgkin lymphoma affecting the lung. PMZL is usually an indolent disease. Clinical and radiological variables associated with shorter survival are largely unknown and no consensus exists on preferred treatment strategy in PMZL. Herein we aimed to identify clinical and radiological features associated with shorter survival and inferior treatment outcomes. Forty patients with PMZL were analyzed. FDG‐avid disease was evident in most patients (93%) with staging PET/CT (n = 15). With a median follow‐up in treated patients (n = 38) of 8.4 years (range 0.07‐18.44), the median progression‐free survival (PFS) and overall survival (OS) were 7.5 years (95% CI 1.8‐9.5) and 15.7 years (95% CI 9.3‐NE) respectively. Shorter PFS was observed in patients who presented at diagnosis with elevated LDH, B symptoms, advanced stage and failed to achieve complete response (CR) after initial treatment. Patients with multifocal lung disease, extrapulmonary MZL and cavitary lesions on CT scans exhibited shorter PFS. Nevertheless, no clinical or radiologic findings were associated with shorter OS. All patients treated with surgery (n = 4) and radiation therapy (n = 3) achieved and remained in CR. No higher grade transformations occurred during the follow‐up period. PMZL exhibited excellent outcomes with a 15‐year PMZL‐related OS of 94.9% (95% CI: 81.25%‐98.7%). Radiation therapy and surgery are potentially curative strategies in localized PMZL.

Comparison of radiologic characteristics and pathological presentations of primary pulmonary lymphoma in 22 patients

OBJECTIVE

This study was performed to compare the radiologic characteristics and pathological presentations of primary pulmonary lymphoma (PPL), explore the possible mechanism underlying its development, summarize its radiologic characteristics, and improve the accuracy of its diagnosis.

METHODS

The medical records of 22 patients pathologically diagnosed with PPL were retrospectively analyzed.

RESULTS

Chest computed tomography (CT) demonstrated single or multiple nodules and masses in the lungs, patchy opacities or consolidation along the bronchovascular bundle, and no significantly enlarged mediastinal or hilar lymph nodes. All 22 cases of PPL were classified as non-Hodgkin's lymphoma (NHL) by transbronchial biopsy, CT-guided needle biopsy, and postoperative pathology. Most (16 cases) were marginal-zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT). Twelve patients had air bronchograms within the lesion, and 13 showed ill-defined lesions with ground-glass brush-like changes.

CONCLUSION

PPL is a rare lung tumor, and most are classified as MALT lymphoma, a subtype of NHL. Chest CT can help to diagnose this disease. Positron emission tomography (PET)/CT is of great clinical value for evaluation of the lesion and patient's general condition. The possibility of PPL should be considered in patients with characteristic CT and PET/CT findings and mild clinical symptoms, and early treatment should be administered.

A retrospective study on the clinical characteristics and radiological features of primary pulmonary lymphoma

Background

The retrospective study was mainly performed to determine the clinical symptoms and radiological characteristics of primary pulmonary lymphoma (PPL) to improve the recognition and diagnosis of the disease.

Methods

Between June 2007 and June 2019, the clinical data and radiological images of the 16 patients with PPL confirmed by pathology were retrospectively analyzed.

Results

Among the 16 patients with PPL (6 males and 10 females, aged 32 to 72 years, with a median age of 55.13 years), 9 patients were mucosa-associated lymphoid tissue lymphoma (MALT) and 7 patients were diffuse large B-cell lymphoma (DLBCL); all of the patients did not suffer from autoimmune disease [such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), or Sjogren’s syndrome (SSS)]; and 11 patients had a long-term smoking history from 10 to 40 years. The common clinical symptoms were as follows: chest discomfort (n=8), cough (n=10), chest pain (n=7), fever (n=6), apnea (n=1), fatigue (n=4) and weight loss (n=3), however, 6 cases did not show clear symptoms at the time of diagnosis. Blood tests revealed anemia (n=6), thrombocytopenia (n=2), lactate dehydrogenase (LDH) level (n=7), C-reactive protein (CRP) (n=9), erythrocyte sedimentation rate (ESR) (n=8) and no tumor-related indexes were detected abnormal. The chest radiological images showed a total of 8 cases with multiple masses, 2 cases with different types of nodes, 4 cases with patchy infiltration or consolidation shadow, with or without an air bronchogram, and 2 cases with a mixed manifestation. All the lesions were only involved in unilateral lung (13 right, 3 left), none of them located on bilateral lung fields. At the time of admission, the patients were misdiagnosed as lung cancer (n=9), pneumonia (n=5), tuberculosis (n=1), and diffuse interstitial lung disease (n=1). Then final pathological diagnosis was confirmed by surgery (n=9), percutaneous lung biopsy (n=5), and bronchoscopic biopsy (n=2).

Conclusions

PPL is a rare disease, though clinical symptoms and radiological characteristics are not typical, they serve as significant clues for the diagnosis and differential diagnosis. Accurate diagnosis mainly depends on histopathological examination, however, conducting a retrospectively study could improve and enrich our knowledge to the disease and reduce inappropriate treatments.

Pulmonary nodular and cystic light chain deposition disease: A retrospective review of 10 cases

INTRODUCTION

Light chain deposition disease (LCDD) rarely involves the lungs. We report clinical and radiologic findings of pulmonary LCDD.

METHODS

We retrospectively identified patients with biopsy-proven pulmonary LCDD seen at Mayo Clinic (Rochester, Minnesota) from January 1997 through December 2018. Demographic, clinical, and imaging features were analyzed.

RESULTS

We identified 10 patients with pulmonary LCDD (median age at diagnosis, 55 years; range, 39-77 years). Eight patients were women and 7 were never-smokers. Dyspnea (n = 3) and chest pain (n = 3) were the most common respiratory symptoms. Associated conditions included Sjögren syndrome (n = 6), sarcoidosis (n = 1), and limited scleroderma (n = 1). Eight patients had mucosa-associated lymphoid tissue (MALT) lymphoma. Among the 9 patients with chest computed tomography (CT) images, 8 (89%) had cysts. Cysts were predominantly distributed in the lower lung and were round or oval. All patients had multiple cysts (5 patients had 1-5 cysts, 3 had >20 cysts). The median diameter of the largest cyst was 18 mm (range, 5-68 mm). All 9 patients had solid nodules (3 had >10 nodules). Five patients had subsolid nodules. The median diameter of the largest solid nodules was 13 mm (range, 6-26 mm). Positron emission tomography-CT images were available for 8 patients. The median maximum standardized uptake value of the most avid pulmonary nodule was 2.2 (range, 1.9-6.0). Two patients died during a median follow-up of 2.3 years (range, 0.5-9.9 years).

CONCLUSIONS

Pulmonary LCDD is characterized by cysts and nodules. The disease is associated with MALT lymphoma, especially in the setting of Sjögren syndrome.

What's New on Quantitative CT Analysis as a Tool to Predict Growth in Persistent Pulmonary Subsolid Nodules? A Literature Review

Pulmonary subsolid nodules (SSNs) are observed not infrequently on thin-section chest computed tomography (CT) images. SSNs persisting after a follow-up period of three to six months have a high likelihood of being pre-malignant or malignant lesions. Malignant SSNs usually represent the histologic spectrum of pulmonary adenocarcinomas, and pulmonary adenocarcinomas presenting as SSNs exhibit quite heterogeneous behavior. In fact, while most lesions show an indolent course and may grow very slowly or remain stable for many years, others may exhibit significant growth in a relatively short time. Therefore, it is not yet clear which persistent SSNs should be surgically removed and for how many years stable SSNs should be monitored. In order to solve these two open issues, the use of quantitative analysis has been proposed to define the "tailored" management of persistent SSNs. The main purpose of this review was to summarize recent results about quantitative CT analysis as a diagnostic tool for predicting the behavior of persistent SSNs. Thus, a literature search was conducted in PubMed/MEDLINE, Scopus, and Web of Science databases to find original articles published from January 2014 to October 2019. The results of the selected studies are presented and compared in a narrative way.

18F-FDG PET/CT or PET Role in MALT Lymphoma: An Open Issue not Yet Solved-A Critical Review

Mucosa-associated lymphoid tissue (MALT) lymphoma involves the mucosa-associated lymphoid tissue potentially arising from any mucosal site, with the stomach as the most common site of involvement. MALT lymphoma is not usually an aggressive disease with a good prognosis except for selected cases. Fluorine-18 (¹⁸F) fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is a noninvasive imaging tool used for staging, restaging, and evaluation of the treatment response in non-Hodgkin and Hodgkin lymphoma. However, its effective role in MALT lymphoma is not yet clear. The open question is whether these lymphomas are ¹⁸F-FDG avid or not, with conflicting results reported in the literature. Consequently, the possible clinical role of ¹⁸F-FDG PET/CT for staging and restaging purposes is under debate. The aim of the present review was to analyze the reported data about the role of ¹⁸F-FDG PET or PET/CT in patients with MALT lymphoma. We performed a comprehensive computer literature search of the Scopus, Cochrane, PubMed/MEDLINE, and Embase databases, including articles reported up to August 2019. We included 32 studies that had analyzed ¹⁸F-FDG PET or PET/CT for patients with MALT lymphoma. We analyzed the metabolic behavior of MALT lymphoma using ¹⁸F-FDG PET and the effect of the PET findings in the staging, treatment response evaluation, and prognosis.

Pulmonary metastases from malignant epithelioid schwannoma of the arm presenting as fast-growing subsolid nodules: Report of an unusual case

Subsolid pulmonary nodules (SSNs) may be the manifestation of benign and malignant conditions. Malignant SSNs usually correspond to the preinvasive or invasive lepidic growth of pulmonary adenocarcinomas. More rarely, malignant SSNs may be the manifestation of primitive pulmonary lymphomas or metastases from extrapulmonary malignancies. In the case of metastases from extrapulmonary malignancies, the SSNs exhibit more aggressive behavior with rapid growth in a short period of time. The present article describes the first case of pulmonary metastases presenting as fast-growing SSNs in a patient with malignant epithelioid schwannoma of the arm.

Quantitative CT Analysis for Predicting the Behavior of Part-Solid Nodules with Solid Components Less than 6 mm: Size, Density and Shape Descriptors

Persistent part-solid nodules (PSNs) with a solid component <6 mm usually represent minimally invasive adenocarcinomas and are significantly less aggressive than PSNs with a solid component ≥6 mm. However, not all PSNs with a small solid component behave in the same way: some nodules exhibit an indolent course, whereas others exhibit more aggressive behavior. Thus, predicting the future behavior of this subtype of PSN remains a complex and fascinating diagnostic challenge. The main purpose of this study was to apply open-source software to investigate which quantitative computed tomography (CT) features may be useful for predicting the behavior of a select group of PSNs. We retrospectively selected 50 patients with a single PSN with a solid component <6 mm and diameter <15 mm. Computerized analysis was performed using ImageJ software for each PSN and various quantitative features were calculated from the baseline CT images. The area, perimeter, mean Feret diameter, linear mass density, circularity and solidity were significantly related to nodule growth (p ≤ 0.031). Therefore, quantitative CT analysis was helpful for predicting the future behavior of a select group of PSNs with a solid component <6 mm and diameter <15 mm.

Two synchronous lung metastases from malignant melanoma: the same patient but different morphological patterns

Malignant melanoma is an aggressive cancer with a high metastatic potential. Among the multiple sites of metastatic disease, the lung is one of the most frequently involved sites. Typically, pulmonary metastases from malignant melanoma occur as solid nodules. Rarely, pulmonary involvement in metastatic melanoma occurs as subsolid nodules.

The present article describes an unusual case of a patient with malignant melanoma that developed two synchronous pulmonary metastases with two different densities on CT images (one solid and the other subsolid) and different morphological patterns on histologic images. The radiologic-pathologic correlation of these two patterns of presentation was also reported.

Pulmonary MALT Lymphoma has variable features on CT

Pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma is the most common primary pulmonary lymphoma. There are limited studies on imaging features of pulmonary MALT lymphoma. We present the computed tomography (CT) manifestations of pulmonary MALT lymphoma and the correlation between CT manifestations and clinical characteristics. Patients (n = 53) with histologically confirmed pulmonary MALT lymphoma who underwent chest CT scanning were retrospectively analyzed. Evaluated findings included distribution of pulmonary lesions, morphological pattern of appearance, contrast enhancement features, size, presence of thoracic lymphadenopathy, and secondary associated features. Pulmonary MALT lymphoma was observed in multiple (79%) and bilateral (66%) disease with random distribution (≥70%) of pulmonary lesions. The most frequent morphological pattern was consolidation (n = 33, 62%), followed by nodule (n = 23, 43%) and mass (n = 11, 21%). Common associated features were air bronchograms and bronchiectasis, especially cystic bronchiectasis and angiogram sign. Asymptomatic patients had less consolidation and bronchiectasis than did symptomatic patients. Cystic bronchiectasis was only observed in the symptomatic group. In conclusion, pulmonary MALT lymphoma manifests as diverse patterns on CT scans. Consolidation combined with cystic bronchiectasis was a characteristic late sign, which may assist in differential diagnosis. High-resolution CT images and multiplanar reconstruction techniques are helpful for accurately determining imaging manifestations.

Clinical features and outcomes of pulmonary lymphoma: A single center experience of 180 cases

BACKGROUND

Pulmonary lymphoma arises primarily from the lung, which is extremely rare, or be secondarily involved by lymphoma. The clinical features, management, and prognostic factors have not been clearly identified.

METHODS

Sixty-three patients with primary pulmonary lymphoma (PPL) and 117 patients with secondary pulmonary lymphoma (SPL) treated in our institution between June 2003 and December 2017 were retrospectively reviewed.

RESULTS

MALT (67%) was the most common pathological subtype of PPL, while DLBCL (48%) was the most common subtype of SPL. Compared to the patients with PPL, the presence of B symptoms, advanced disease stage, intermediate-high or high risks of IPI and NCCN-IPI, elevated inflammatory parameters, and elevated cytokine levels were all observed in patients with SPL. Consolidation was the most frequent radiological finding in PPL cases, while nodules were the most frequent finding in SPL. With a median follow-up of 35 months (range 2-176), the estimated 3-year OS rates were 95%, 100%, 70% and 50% in indolent PPL, indolent SPL, aggressive PPL, and aggressive SPL, respectively. In indolent pulmonary lymphoma, none of the prognostic factors we studied significantly influenced survival of the patients. In aggressive pulmonary lymphoma, univariate analysis showed that NCCN-IPI was related to OS in PPL. Multivariate analysis showed that β2-MG was an independent prognostic factor for OS in SPL.

CONCLUSIONS

Primary and secondary pulmonary lymphoma differ in their clinical features and outcome. Furthermore, β2-MG is the independent prognostic factor for OS in patients with aggressive SPL.

18F-FDG PET/CT for staging and response assessment of primary parotid MALT lymphoma with multiple sites involvement: A case report

RATIONALE

Mucosa-associated lymphoid tissue (MALT) lymphoma is an extranodal low-grade B cell lymphoma that generally exhibits an indolent clinical course. Currently, the application of F-fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET/CT) in MALT lymphoma is still controversial. Herein, we reported a case of using F-FDG PET/CT for staging and response assessment of primary parotid MALT lymphoma with multiple sites involvement. As far as we know, there are no similar case reports have been published before.

PATIENT CONCERNS

A 71-year-old woman, who received mass resection twice during the past 2 years due to the repeatedly relapse of facial painless masses and diagnosed as reactive lymphoid hyperplasia by pathologic tests. However, the pathological diagnosis was then changed to primary parotid MALT lymphoma after left parotidectomy operation because of a new mass found in her left parotid. Four months later, the right eyelid of the patient swelled with a blurred vision. Then, F-FDG PET/CT scan was performed for staging, and the imaging results showed an abnormal increase of F-FDG uptake in multiple sites including bilateral ocular adnexal, lungs, pleura, occipital subcutaneous tissue, left kidney, and lymph nodes.

DIAGNOSES

The patient was diagnosed as primary parotid MALT lymphoma with Ann Arbor stage of IVA based on the F-FDG PET/CT findings.

INTERVENTIONS

The patient received 4 cycles of chemotherapy, followed by a partial metabolic remission (PMR), which was determined by interim F-FDG PET/CT, and finally additional 2 cycles of chemotherapy.

OUTCOMES

The follow-up study illustrated that the patient had been alive and doing well at 12 months after chemotherapy.

LESSONS

Although MALT lymphoma normally localizes in the primary organs, the involvement of multiple organs and lymph nodes is possible. The use of PET/CT demonstrated significant clinical values in the accurate staging and response assessment of F-FDG-avid MALT lymphoma. It is potentially useful for indicating the progress and transformation of MALT lymphoma, and guidance in localization of pathological biopsy. It is also helpful for clinicians to choose reasonable treatment strategy and improve the prognosis of patients.

Prognostic role of baseline 18 F-FDG PET/CT parameters in MALT lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma is an indolent lymphoma with good prognosis and variable fluorine-18 fluorodeoxyglucose (¹⁸ F-FDG) avidity. Many possible prognostic factors have been investigated with controversial results, but the possible prognostic role of ¹⁸ F-FDG positron emission tomography/computed tomography (PET/CT) remains unclear. Our aim was to evaluate the prognostic impact of qualitative and semiquantitative baseline PET/CT parameters on outcome of MALT lymphoma. We retrospectively enrolled 161 patients with histologically confirmed MALT lymphoma who underwent ¹⁸ F-FDG PET/CT before any treatment. PET images were qualitatively and semiquantitatively analyzed by measuring the maximum standardized uptake value body weight (SUVbw), lean body mass (SUVlbm), body surface area (SUVbsa), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). The Kaplan-Meier method was used to estimate the progression-free survival (PFS) and overall survival (OS) times. Cox regression models were performed to determine the relation between PET/CT features and OS and PFS. Ninety-eight patients had positive ¹⁸ F-FDG PET/CT showing ¹⁸ F-FDG uptake (mean SUVbw, 10.1; SUVlbm, 7.2; SUVbsa, 2.7; MTV, 88.8; and TLG, 526); the remaining 63 were not ¹⁸ F-FDG avid. ¹⁸ F-FDG avidity was significantly correlated with tumor size and Ki-67 score. Relapse/progression of disease occurred in 47 patients with an average time of 40.2 months; death occurred in 12 patients with an average of 59 months. At a median follow-up of 62 months, median PFS and OS were 52 and 62 months, respectively. Advanced tumor stage and extragastric site were demonstrated to be independent prognostic factors for PFS, while only tumor stage for OS. Instead, PET/CT parameters were not related to survival, despite positive correlation at univariate analysis between MTV and TLG with PFS and positive PET/CT with PFS and OS. In conclusion, a 61% rate of PET avidity in biopsy-confirmed MALT lymphoma was found, and it was correlated with tumor size and Ki-67 score. Only tumor stage and localization were independently correlated with PFS and OS.

HRCT in primary pulmonary lymphoma: can CT imaging phenotypes differentiate histological subtypes between mucosa-associated lymphoid tissue (MALT) lymphoma and non-MALT lymphoma?

Background

Primary pulmonary lymphoma (PPL) mainly comprises mucosa-associated lymphoid tissue (MALT) lymphoma as well as other subtypes of lymphoma. Different phenotypes of PPL demonstrate various high-resolution computed tomography (HRCT) features. We aimed to evaluate the value of HRCT in the diagnosis and differential diagnosis of PPL, especially between MALT lymphoma and non-MALT lymphoma and the correlation between CT and pathological features.

Methods

We performed a retrospective analysis on 72 patients with PPL confirmed by pathology between 2007 and 2016. We compared the CT characteristics and correlation with pathological findings between MALT lymphoma and non-MALT lymphoma groups.

Results

All 72 patients with PPL were classified into two groups: low-grade MALT lymphoma (MALToma) (56/72) and high-grade non-MALT lymphoma (non-MALToma) (16/72). The latter group consisted of diffuse large B cell lymphoma (8/72), Hodgkin's lymphoma (3/72), T-cell lymphoma (4/72), and intravascular large B-cell lymphoma (1/72). A total of 168 lesions were analyzed, including 57 cases with multiple lesions and 15 cases with single lesion. The manifestation of four distribution patterns: nodular or mass-like involvement pattern, diffuse interstitial lung disease (DILD) pattern, pneumonia-like consolidative pattern and mixed pattern was not significantly different between MALToma and non-MALToma (all P>0.05). Signs of air bronchogram and CT angiogram occurred significantly more often in individuals with MALToma group than those with non-MALToma (75% vs. 25%, P=0.001; 64.3% vs. 12.5%, P<0.001; respectively). Conversely, the halo sign presented more often in non-MALToma than in MALToma patients (19% vs. 63.6%, P=0.02). In addition, the butterfly sign was only observed in four patients with MALToma.

Conclusions

HRCT imaging phenotypes were beneficial in the diagnosis of PPL. Solitary or multifocal nodules/masses and consolidation were the most common imaging patterns. The air bronchogram sign, CT angiogram sign, halo sign, and butterfly sign could be potential to help to differentiate MALToma from non-MALToma.

Endobronchial Mucosa-associated Lymphoid Tissue Lymphoma: A Report of Two Cases and a Review of the Literature

Primary endobronchial mucosa-associated lymphoid tissue lymphoma (EML) is rare. We reviewed 20 cases of EML, including ours and case reports. We found that the location of tumor in 70% of these cases was limited to the trachea and main bronchus, and the form of tumor in 61% of these cases was several nodular protrusions. If a patient exhibits these characteristics, adequate specimen collection on bronchoscopy is important. Because the prognosis for patients with EML is good, tumors on the trachea and main bronchus should be treated, while those on the peripheral airway can be watched carefully.

Bronchial Mucosa-Associated Lymphoid Tissue Lymphoma Staged by 11C-Methionine

A 57-year-old man had a diagnosis of a bronchial mucosa-associated lymphoid tissue lymphoma in the left lung and monoclonal gammopathy. The patient underwent whole-body C-methionine PET/CT, in order to evaluate the amino acid avidity of the lesion and to stage the bronchial mucosa-associated lymphoid tissue lymphoma. C-methionine uptake was detected in the lung lesion and in the mediastinal lymph nodes.

Primary pulmonary lymphoproliferative neoplasms

Pulmonary lymphoproliferative neoplasms are rare lung tumors and account for <1% of all lung tumors. Among them, primary pulmonary lymphomas (PPL) constitute the majority, which include Non-Hodgkin's lymphoma (NHL) that comprise of mucosa-associated lymphoid tissue lymphoma, diffuse large B-cell lymphomas and other rare types of NHL and lymphomatoid granulomatosis. HL, which arises secondary to contiguous spread from the mediastinum, is the rarest type of PPL. Other entities described within the umbrella of pulmonary lymphoproliferative neoplasms include pleural lymphomas and posttransplant lymphoproliferative disorders (PTLD) - which occurs in the poststem cell and organ transplant patients. These neoplasms although rare, have a favorable prognosis, which does not depend on disease resectability. Moreover, with its nonspecific presentation, diagnosis is challenging, which often leads to delayed diagnosis or misdiagnosis in many cases. Therefore, knowledge of this entity is important for the practicing pulmonologist. This review article aims to describe the clinical presentation, diagnosis and management of primarily the entities within PPL, as well as pleural lymphomas and PTLD.