Lymphoproliferative Lung Disorders: A Radiologic-Pathologic Overview. Part II: Neoplastic Disorders

Diagnostic Approach to Pulmonary B-Cell Lymphomas in Small Biopsies, with Practical Recommendations to Avoid Misinterpretation

Pulmonary lymphomas are rare. With the current less invasive approaches used to obtain material for diagnosis, the diagnosis of pulmonary lymphoma is now frequently established in a small biopsy rather than in a resection. Therefore, the diagnosis has become more challenging and requires correlation with the clinico-radiologic presentation and with ancillary studies (immunohistochemistry, flow cytometry, cytogenetics, and/or molecular analysis). Due to the rarity of pulmonary lymphomas, clinical suspicion of a lymphomatous process is low at initial presentation, and material may be only submitted for histopathology. For this reason, herein, we provide recommendations to arrive at the correct diagnosis of the most common lung B-cell lymphomas (marginal zone lymphoma of mucosa-associated lymphoid tissue, diffuse large B-cell lymphoma, intravascular large B-cell lymphoma, lymphomatoid granulomatosis) in the setting of small biopsies, utilizing only immunohistochemistry. The differential diagnosis varies according to the lymphoma subtype and includes reactive conditions, solid tumors, and other hematolymphoid malignancies. Although morphology and immunohistochemistry may be sufficient to establish a diagnosis, in some cases, the best recommendation is to obtain additional tissue via a VATS biopsy/wedge resection with material submitted for flow cytometry, cytogenetics, and/or molecular studies to be able to properly classify a pulmonary lymphoid process.

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.

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.

Pearls and pitfalls in imaging of mediastinal masses

In imaging of the mediastinum, advances in computed tomography (CT), and magnetic resonance imaging (MRI) technology enable improved characterization of mediastinal masses. Knowledge of the boundaries of the mediastinal compartments is key to accurate localization. Awareness of distinguishing imaging characteristics allows radiologists to suggest a specific diagnosis or narrow the differential. In certain situations, MRI adds value to further characterize mediastinal lesions.

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.

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.

Primary pulmonary lymphoma: imaging findings in 30 cases

PURPOSE

To present our experience of cases of primary pulmonary lymphoma (PPL) found between January 2002 and July 2018, focusing on the radiological features and the differential diagnosis in order to contribute to the difficult role of the radiologist in the disease identification and to help the clinicians to reach the diagnosis.

MATERIALS AND METHODS

CT scans of 30 patients (14 men and 16 women, aged 58-86, mean age 72 years) with PPL were retrospectively reviewed. All patients had a histopathological confirmation of the disease: MALT lymphoma (23 patients, 76.6%); diffuse large B-cell lymphoma-DLBCL (seven patients, 23.4%). All the staging CT scans were evaluated by three experienced radiologists dedicated to thoracic disease in order to radiologically define the predominant pattern of presentation.

RESULTS

The following parenchymal patterns were observed: 11 patients with single/multiple nodules, five with masses/mass-like consolidations, 14 with consolidations with air bronchogram, 16 with ground-glass opacity, ten with angiogram sign, 22 with perilymphatic and/or peribronchovascular spread, 15 with associated lymphadenopathies, and 13 with pleural/chest wall involvement. The main characteristics of PPLs were the presence of consolidations and ground-glass opacities, with perilymphatic and/or bronchovascular spread.

CONCLUSION

All the characteristics of the work should alert the radiologist to consider lymphoma among the possible differential diagnoses, always correlating the results of the CT examination with appropriate clinical laboratory evaluations.

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.

Approach to Peribronchovascular Disease on CT

Diseases that are predominantly peribronchovascular in distribution on computed tomography by definition involve the bronchi, adjacent vasculature, and associated lymphatics involving the central or axial lung interstitium. An understanding of diseases that can present with focal peribronchovascular findings is useful for establishing diagnoses and guiding patient management. This review will cover clinical and imaging features that may assist in differentiating amongst the various causes of primarily peribronchovascular disease.

Primary Pulmonary Lymphoma: A Retrospective Analysis of 27 Cases in a Single Tertiary Hospital

BACKGROUND

The objective of this study was to improve the understanding of primary pulmonary lymphoma (PPL) for clinicians.

METHODS

We enrolled 27 patients diagnosed with PPL in the First Affiliated Hospital of Soochow University from January 2000 to December 2016. The clinical manifestations, imaging findings, pathologic features, treatments and prognosis of the patients were collected.

RESULTS

The male to female ratio was 1.5:1 and the average age was 54.6 ± 15.7 years old. Nine patients were asymptomatic. The main manifestations were cough, expectoration, bloody sputum and fever. The imaging findings presented as nodule, mass, pneumonia or consolidation. There were 2 cases of Hodgkin's lymphoma, 18 cases of non-Hodgkin's lymphoma and 7 cases of undifferentiated lymphoma. Non-Hodgkin's lymphoma cases were divided into T-cell lymphoma (n = 2), mucosa-associated lymphoid tissue lymphoma (MALT) (n = 11), diffuse large B-cell lymphoma (n = 3), small B-cell lymphoma (n = 1) and plasmacytoid B-cell lymphoma (n = 1). Ten MALT cases survived and 1 diffuse large B-cell lymphoma case has been in stable condition for 71 months after surgery and chemotherapy. The international prognostic index was related to the prognosis of PPL.

CONCLUSIONS

The clinical manifestations and imaging findings of PPL were nonspecific. The prognosis of MALT was better than other types of PPL. The International prognostic index can be used for predicting the prognosis of PPL.

Chronic Airspace Diseases

Airspace disease can be acute or chronic and commonly present as consolidation or ground-glass opacity on chest imaging. Consolidation or ground-glass opacity occurs when alveolar air is replaced by fluid, pus, blood, cells, or other material. Airspace disease is considered chronic when it persists beyond 4-6 weeks after treatment. These can be secondary to certain infectious, inflammatory, or neoplastic conditions. Computed tomography of the chest is usually performed in this set of patients to identify characteristic imaging findings. Familiarity with the differential diagnosis and characteristic imaging findings for chronic airspace disease is very important for guiding patient's management in a timely fashion.

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

OBJECTIVE

The aim of the study was to evaluate the CT and fluorine-18-fluorodeoxyglucose positron emission tomography/CT (¹⁸F-FDG PET/CT) imaging findings of lung mucosa associated lymphoid tissue (MALT) lymphoma.

METHODS

28 patients with histologically confirmed pulmonary MALT lymphoma who underwent a chest CT and ¹⁸F-FDG PET/CT for staging were retrospectively analysed. The CT images were evaluated to determine morphological pattern of appearance, laterality, localization, number, size, presence of thoracic lymphadenopaties and secondary/combined findings. PET images were analysed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax), lesion-to-liver SUVmax ratio and lesion-to-blood pool SUVmax ratio. The relationship between qualitative and semi-quantitative features at ¹⁸F-FDG PET/CT and CT findings were also analysed.

RESULTS

A total of 57 pulmonary lesions were identified by CT: 37 areas of consolidation, 4 masses, 12 nodules and 4 ground-glass opacities. Solitary and multiple lesions were detected in 10 and 18 patients, respectively; among patients with multiple lesions, 16 were bilateral and 2 unilateral. ¹⁸F-FDG PET/CT revealed increased ¹⁸F-FDG uptake in 47/57 lesions, in 26/28 patients. 18F-FDG avidity was significantly associated only with tumour size.

CONCLUSIONS

Pulmonary MALT lymphoma is ¹⁸F-FDG avid in most cases and ¹⁸F-FDG avidity is correlated with tumour size. Consolidation is the most frequent morphological pattern of disease presentation. Advances in knowledge: This study demonstrated that lung MALT lymphoma are ¹⁸F-FDG avid in most cases depending on tumour size. Single or multiple areas of consolidation are the most common pattern of presentation of lung MALT lymphoma at CT.

Pathology of Extranodal Lymphoma

An overview of the pathology of extranodal lymphoma is presented. The emphasis of this presentation is on the classification system of extranodal lymphomas, including both B-cell and T-cell lymphomas, based on their morphology, phenotype, and molecular alterations.

Primary Pulmonary Lymphomas

Primary lung lymphoma (PLL) is a rare disease that comprises <0.5% of all primary lung tumors. It is defined as lymphoma confined to the lung with or without hilar lymph node involvement at the time of diagnosis or up to 3 months thereafter. Patients with PLL may be asymptomatic or manifest nonspecific clinical symptoms, for example, cough, chest pain, and dyspnea. Some individuals may be immunosupressed or have an autoimmune disorder. Radiologically, PLL can mimic pneumonia, lung carcinoma, or metastasis, and therefore, histologic confirmation is mandatory for definitive diagnosis. Primary lung marginal zone lymphoma of mucosa-associated lymphoid tissue type comprises 70% to 80% of cases. Less common B-cell lymphomas include diffuse large B-cell lymphoma, lymphomatoid granulomatosis (LyG), plasmacytoma, and other small lymphocytic lymphomas. PLLs of T-cell origin, largely represented by anaplastic large cell lymphoma, are extremely rare. LyG is an Epstein-Barr virus (EBV)-driven B-cell lymphoid neoplastic proliferation rich in T cells that produces vasculitis. The disease may present at different stages of progression. Differential diagnosis of PLL varies according to the lymphoma subtype: pulmonary mucosa-associated lymphoid tissue lymphoma should be distinguished from reactive inflammatory conditions, whereas high-grade lymphomas may resemble poorly differentiated lung carcinoma, metastatic disease, and other lymphomas. LyG can resemble inflammatory, infectious, and other lymphoid neoplastic processes. A panel of immunohistochemical markers, flow cytometry, and molecular methods are necessary to confirm the diagnosis in the majority of cases. In this article we review the clinical, radiologic, pathologic, and molecular characteristics of several B-cell and T-cell PLLs with exception of Hodgkin lymphoma and posttransplant lymphoproliferative disorder.