Tumors and tumorlike conditions of the large airways. AJR Am J Roentgenol. 2013;201:301-313. [PMID: 23883210 DOI: 10.2214/ajr.12.9043]

ACR Lung-RADS v2022: Assessment Categories and Management Recommendations

The ACR created the Lung CT Screening Reporting and Data System (Lung-RADS) in 2014 to standardize the reporting and management of screen-detected pulmonary nodules. Lung-RADS was updated to version 1.1 in 2019 and revised size thresholds for nonsolid nodules, added classification criteria for perifissural nodules, and allowed for short-interval follow-up of rapidly enlarging nodules that may be infectious in etiology. Lung-RADS v2022, released in November 2022, provides several updates including guidance on the classification and management of atypical pulmonary cysts, juxtapleural nodules, airway-centered nodules, and potentially infectious findings. This new release also provides clarification for determining nodule growth and introduces stepped management for nodules that are stable or decreasing in size. This article summarizes the current evidence and expert consensus supporting Lung-RADS v2022.

ACR Lung-RADS v2022: Assessment Categories and Management Recommendations

The American College of Radiology created the Lung CT Screening Reporting and Data System (Lung-RADS) in 2014 to standardize the reporting and management of screen-detected pulmonary nodules. Lung-RADS was updated to version 1.1 in 2019 and revised size thresholds for nonsolid nodules, added classification criteria for perifissural nodules, and allowed for short-interval follow-up of rapidly enlarging nodules that may be infectious in etiology. Lung-RADS v2022, released in November 2022, provides several updates including guidance on the classification and management of atypical pulmonary cysts, juxtapleural nodules, airway-centered nodules, and potentially infectious findings. This new release also provides clarification for determining nodule growth and introduces stepped management for nodules that are stable or decreasing in size. This article summarizes the current evidence and expert consensus supporting Lung-RADS v2022.

Tracheal resection anastomosis for rare tracheal inflammatory lesions mimicking malignancy: report of 2 cases

BACKGROUND

Tumor-like lesions of the trachea are rare and challenging in diagnosis and management. Inflammatory myofibroblastoma, also known as Inflammatory pseudo tumors (IPTs), as well as Rosai Dorfman Disease (RDD) are inflammatory lesions that may involve the central airways with variable non-specific clinical features mimicking tumors.

CASE PRESENTATION

In this study 2 cases with tumor-like lesions are presented. One case with an inflammatory pseudotumor and the other one with Rosai-Dorfman disease affecting the upper trachea. Both cases were successfully managed with tracheal resection anastomosis.

CONCLUSION

Tracheal Inflammatory myofibroblastoma, and Rosai-Dorfman diseases are rare tumor like lesions that present with upper airway obstruction. Despite being benign, these lesions may have features suggestive of malignancy, requiring prompt management. Complete surgical excision by segmental resection and primary anastomosis (if feasible) is the treatment of choice with an optimum outcome.

Utility of Virtual Bronchoscopy in Tracheal Tumors

Tracheal tumors are rare neoplasms, most of which are malignant. Conventional bronchoscopy (CB) and biopsy are used in the primary evaluation of these tumors, while Contrast-Enhanced Computed Tomography (CECT) is usually used for assessing extraluminal extension and nodal spread. Virtual bronchoscopy, created by postprocessing the three-dimensional volume data acquired from CECT, attempts to recreate the endoluminal features as seen in CB. The complexity of tracheal surgery necessitates accurate preoperative localization of the lesion and planning. It can assist in evaluation of patients in whom CB cannot be performed and for airway assessment in a preoperative setting. Although it cannot replace CB, it can be resorted to, in specific clinical scenarios. In this pictorial essay, we aim to highlight the technique, role, and clinical utility of Virtual Bronchoscopy (VB) in tracheal tumors.

Malignant and Benign Tracheobronchial Neoplasms: Comprehensive Review with Radiologic, Bronchoscopic, and Pathologic Correlation

Tracheobronchial neoplasms are much less common than lung parenchymal neoplasms but can be associated with significant morbidity and mortality. They include a broad differential of both malignant and benign entities, extending far beyond more commonly known pathologic conditions such as squamous cell carcinoma and carcinoid tumor. Airway lesions may be incidental findings at imaging or manifest with symptoms related to airway narrowing or mucosal irritation, invasion of adjacent structures, or distant metastatic disease. While there is considerable overlap in clinical manifestation, imaging features, and bronchoscopic appearances, an awareness of potential distinguishing factors may help narrow the differential diagnosis. The authors review the epidemiology, imaging characteristics, typical anatomic distributions, bronchoscopic appearances, and histopathologic findings of a wide range of neoplastic entities involving the tracheobronchial tree. Malignant neoplasms discussed include squamous cell carcinoma, malignant salivary gland tumors (adenoid cystic carcinoma and mucoepidermoid carcinoma), carcinoid tumor, sarcomas, primary tracheobronchial lymphoma, and inflammatory myofibroblastic tumor. Benign neoplasms discussed include hamartoma, chondroma, lipoma, papilloma, amyloidoma, leiomyoma, neurogenic lesions, and benign salivary gland tumors (pleomorphic adenoma and mucous gland adenoma). Familiarity with the range of potential entities and any distinguishing features should prove valuable to thoracic radiologists, pulmonologists, and cardiothoracic surgeons when encountering the myriad of tracheobronchial neoplasms in clinical practice. Attention is paid to any features that may help render a more specific diagnosis before pathologic confirmation. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

68Ga-DOTATATE PET/CT Scan as a Valuable Tool for Diagnosis and Staging of the Rare Entity of Tracheal Paragangliomas

ABSTRACT

Primary paraganglioma of the trachea is a rare differential among more common tracheal masses. Definitive diagnosis of tracheal masses is obtained via endoscopic biopsy. Utilization of 68Ga-DOTATATE PET/CT is valuable in the workup of these lesions as paragangliomas would have significantly higher radiotracer uptake compared with the more common squamous cell and adenoid cystic carcinomas. This is particularly important in tracheal paragangliomas, which are typically friable and hypervascular with higher risk of significant bleeding on biopsy. In addition, 68Ga-DOTATATE PET/CT can be used to evaluate for local invasion and metastatic disease as a 1-step imaging modality.

Large tracheoesophageal granular cell tumor: An atypical case presentation, location, and management

Introduction

Presentation of case

Conclusion

•

Granular cell tumors (GCT) are rare tumors of the head and neck.

•

A 42-year-old man presented to the Emergency Department after a motor vehicle accident with a 3.2 × 5.5 cm mass anterior to the esophagus and posterior to the tachea.

•

The patient underwent a transcervical excision of the retrotracheal tumor, which was positive for CD68, CD163, S100, and SOX10, confirming a GCT.

•

This is a distinctive presentation of a large (5.5cm) GCT in the plane between the trachea and esophagus that hasn't been shown in the literature

Endobronchial Leiomyoma: A case report with cryoprobe extraction and review of literature

Large airway tumors are uncommon, accounting for about 0.6% of all pulmonary tumors [[1], [2], [3]]. The majority of these tumors (80–90%) are malignant, represented primarily by squamous cell carcinoma and adenoid cystic carcinoma [2,4]. Benign central airway tumors are less common and are generally comprised of hamartomas and papillomas. Tracheobronchial leiomyomas are exceedingly rare, representing only about 0.6% of all benign lung neoplasms [3]. We report here on a case of primary endobronchial leiomyoma without uterine involvement treated successfully with cryoresection with excellent outcome.

Contrast-enhanced CT longitudinal tail sign as a marker of positive resection margins in adenoid cystic carcinoma of the central airway

Background

Due to submucosal infiltration’s biological nature along the airway, adenoid cystic carcinoma (ACC) frequently leaves positive surgical margins. This study evaluated the clinicopathologic, and computed tomography (CT) features for predicting surgical margin status in central airway ACC.

Methods

We retrospectively analyzed the files of 71 patients with ACC of the central airway proven by histopathology and surgery who had presented between January 2010 and December 2018. All patients were classified into positive and negative surgical margin groups according to margin status. Univariate analysis and multivariable logistic regression models were then performed to compare demography, histopathology, and CT characteristics between ACC patients with positive and negative margins.

Results

After surgical resection, 59 (83.1%) patients had positive margins, and 12 (16.9%) had negative margins. The contrast-enhanced CT (CECT) longitudinal tail sign (LTS) was identified in 55 of 59 (93.2%) patients with positive margins and was the only feature that had a significant association with positive margins (odds ratio 41.250, 95% CI: 7.886–215.767; P<0.001). Moreover, positive margins in upper or/and lower directions were associated with the LTS in corresponding directions (P<0.001).

Conclusions

Most central airway ACC patients exhibited positive margins following surgery. The appearance of the LTS on CECT was significantly associated with positive margins and could help preoperatively predict the submucosal invasion of ACC.

CT diagnosis and prognosis prediction of tracheal adenoid cystic carcinoma

PURPOSE

To evaluate computed tomography (CT) features and establish a predictive model for the clinical diagnosis and prognosis of tracheal adenoid cystic carcinoma (ACC).

METHOD

From January 2010 to December 2018, 82 patients with tracheal tumors, including 46 patients with ACC confirmed by surgery and histopathology, were enrolled in this study. These patients' clinicopathologic information, CT features and survival outcomes were recorded and analyzed. Independent predictors of diagnosis and prognosis of tracheal ACC were determined by both univariate and multivariate analyses.

RESULTS

Compared with tracheal non-ACC patients, univariate analysis showed that ACC patients were more likely to have extensive longitudinal length (p < 0.001) and to appear as annular wall thickening (p = 0.001), transmural growth (p = 0.036), poorly defined border (p = 0.003) and mild enhancement (p = 0.001). Multivariate logistic analysis showed that longitudinal length and enhancement degree were independent predictors of tracheal ACC. The 3-year and 5-year disease-free survival (DFS) were 75.7 % and 64.5 %, respectively. Longitudinal length (≥ 34 mm), transverse length (≥ 20 mm) and transmural growth were associated with poor DFS in univariate analysis. After multivariate adjustment, only transverse length (≥ 20 mm) was an adverse prognostic factor for DFS (hazard ratio = 4.594, 95 % confidence interval = 1.240-17.017; p = 0.022).

CONCLUSIONS

CT longitudinal length and enhancement degree of tumors showed satisfactory discrimination for tracheal ACC. Excessive CT transverse length might be an unfavorable indicator for ACC recurrence and could be helpful for predicting the survival outcomes of ACC at the initial diagnosis.

Inflammatory Lesions Mimicking Chest Malignancy: CT, Bronchoscopy, EBUS, and PET Evaluation From an Oncology Referral Center

Infective and inflammatory diseases can mimic malignancy of the lung. Granulomatous inflammations are common causes of pulmonary nodule, mass, or nodal disease. Systemic infection or inflammation also commonly involves the lung that may raise suspicion of a malignant process. Even in patients with a known malignancy, inflammatory diseases can simulate new metastasis or disease progression. Knowledge of the imaging features of these diseases is essential to prevent missed or overdiagnosis of malignancy. Radiologists also need to be familiar with the scope and limitations of bronchoscopy, endobronchial ultrasound, PET-CT, and biopsy to guide clinical management. In this review, we discuss the imaging features and diagnostic approach of common mimickers of chest malignancy that involve the chest wall, pleura, lung parenchyma, and mediastinal nodes.

Interventional Therapies for Central Airways

Central airway obstruction (CAO) is a dangerous and increasingly common problem. CAO refers to lesions causing narrowing of the trachea or mainstem bronchi and is generally divided into malignant and nonmalignant categories. These 2 entities may be caused by a variety of thoracic and extrathoracic diseases. Imaging is critical during the initial assessment of CAO and may help thoracic physicians focus the differential diagnosis and plan the safest and most appropriate diagnostic and therapeutic interventions. However, direct visualization via flexible or rigid bronchoscopy is often necessary for diagnostic and treatment purposes. A large number of procedures can be performed through bronchoscopy, with the goal of relieving the obstruction and improving patency of the airway. Deciding which procedure to perform is based both upon the type of lesion and whether the lesion is due to a malignant or nonmalignant process. Possible interventions include mechanical debridement, laser therapy, argon plasma coagulation, electrocautery, brachytherapy, and stent placement. Immediate postoperative and follow-up imaging is crucial to monitor for immediate, subacute, and chronic complications as well as disease progression and recurrence.

Inflammatory Endobronchial Myofibroblastic Tumor: A Case Report

Inflammatory myofibroblastic tumor is a rare benign lesion that accounts for 0.04–1% of all lung tumors and usually appears as a solitary pulmonary nodule or mass. Here, we report the case of an endobronchial inflammatory myofibroblastic tumor in a 21-year-old man with a focus on the imaging findings and a review of previous literature.

Tracheobronchial Tumors: Radiologic-Pathologic Correlation of Tumors and Mimics

Tracheobronchial masses encompass a broad spectrum of entities, ranging from benign and malignant neoplasms to infectious and inflammatory processes. This article reviews the cross-sectional findings of tracheal tumors and tumor-like entities, correlates imaging findings with histologic pathology, and discusses pearls and pitfalls in accurately diagnosing and classifying tracheal tumors and mimics.

CT features and differential diagnosis of primary pulmonary mucoepidermoid carcinoma and pulmonary adenoid cystic carcinoma

Background

The differential diagnosis of primary pulmonary mucoepidermoid carcinoma (PMEC) and pulmonary adenoid cystic carcinoma (PACC) is difficult, because both tumors could be similar in terms of certain characteristics on CT.

Methods

The CT findings from 24 cases of PMEC and 30 cases of PACC were retrospectively analyzed. According to the position of the lesion in airway, we divided these cases into three types: central, hilar, and peripheral.

Results

In PMEC, there were 7 cases of central type, 14 cases of hilar type, and 3 cases of peripheral type. And, 57.1% PMEC cases of the hilar type were accompanied by distal bronchial dilatation with mucoid impaction. Patchy areas of low density were observed in 79.2% cases of PMEC. The solid part of most lesions showed moderate (37.5%) or severe enhancement (45.8%). However, in PACC, there were 24 cases of central type, 3 cases of hilar type, and 3 cases of peripheral type. PACC had more cases of central type than PMEC. Moreover, longitudinal extent greater than 3 cm was observed in 62.5% PACC cases of the central type, while infiltration of the luminal perimeter more than 1/2 perimeter was observed in 95.8% PACC cases of the central type. Patchy areas of low density were observed in 26.7% cases of PMEC. In PACC cases, the solid part of 76.7% lesions showed slight enhancement. Cavities could be observed in PMEC, but not in PACC.

Conclusions

PMEC and PACC have different CT features in various airway locations. PMEC is usually the hilar type, accompanied by distal bronchial dilatation with mucoid impaction. However, PACC is usually the central type, with longitudinal extent greater than 3 cm and infiltration of the luminal wall more than 1/2 perimeter. Patchy areas of low density and moderate or severe enhancement are more prominent in PMEC. However, slight enhancement is more common in PACC.

Case 260: Endobronchial Posttransplantation Lymphoproliferative Disease

History A 31-year-old woman with a history of bilateral orthotopic lung transplantation performed 10 months earlier for cystic fibrosis presented for a routine follow-up appointment, with her chief symptom being a cough. The cough started approximately 1 month prior to this appointment and was minimally productive of clear to yellow phlegm. In addition to her cough, she reported increased sinus congestion and a sensation of "something in her upper chest." She denied shortness of breath, wheezing, hemoptysis, or cigarette smoking. Review of systems was negative for fever, chills, or night sweats. At physical examination, the patient was afebrile, borderline tachycardic (heart rate, 99 beats per minute), and mildly hypertensive (blood pressure, 138/99 mm Hg). Oxygen saturation was 96% on room air. Laboratory evaluation revealed a white blood cell count of 3.5 × 10⁹/L (normal range, [3.2-9.8] × 10⁹/L). Pulmonary function testing was notable for a newly decreased ratio of forced expiratory volume in 1 second (FEV₁) to forced vital capacity (FVC) of 64% (2.0 and 3.4 L, respectively) (normal FEV₁-to-FVC ratio, 80%), suggesting an obstructive lung process. One month prior to presentation, the patient's sputum cultures grew Pseudomonas and methicillin-resistant Staphylococcus aureus. The patient showed no evidence of active infection at the time of bronchoscopy. Thus, the bacteria were favored to reflect colonization, and antibiotic therapy was not administered at that time. The patient was taking an immunosuppression regimen of mycophenolate mofetil (CellCept; Genentech, San Francisco, Calif) (1 g twice daily), prednisone (10 mg daily), and tacrolimus (Prograf; Astellas Pharma US, Northbrook, Ill) (goal therapeutic range, 12-14 ng/mL). The patient was sent for posteroanterior and lateral chest radiography followed by chest CT ( Figs 1 - 3 ) and fluorine 18 (¹⁸F) fluorodeoxyglucose (FDG) PET/CT ( Fig 4 ).

Ewing's Sarcoma/Peripheral Primitive Neuroectodermal Tumors in Bronchus

Ewing sarcoma/peripheral primitive neuroectodermal tumors (ES/pPNET), a member of the Ewing sarcoma family of tumors, is a malignant soft tissue tumor with small undifferentiated neuroectodermal cells. Primary trachea-bronchial ES/pPNET is very rare. The most common pulmonary ES is due to a metastasis. We describe a case of ES/pPNET which originated in the left basal trunk bronchus. The patient was a 30-year-old male, presenting with irritable cough and fever for 10 days. A tumor of 60 mm in diameter was found in the left basal trunk bronchus, extending to the left lower lobe. No distant metastases were detected. Histopathological examination revealed a malignancy of ES/pPNET with a diffuse proliferation of round cells, a Flexner-Wintersteiner rosette formation and positive staining for CD99. The patient was successfully treated with a combination of left lower lobectomy and adjuvant chemotherapy and has remained disease-free for approximately 18 months at follow-up. This case highlights that ES/pPNET should be considered as a differential diagnosis in cases of trachea-bronchial tumors.

Imaging of the trachea

Numerous benign and malignant tracheal diseases may affect the trachea primarily and secondarily. While the posterior anterior (PA) and lateral chest radiograph is the conventional study for initial evaluation of the trachea and central airways, findings may not always be apparent on conventional radiographs, and further evaluation with cross sectional imaging is usually necessary. Computed tomography (CT) is the imaging modality of choice for imaging the trachea and bronchi. Familiarity with the imaging appearances of the normal and diseased trachea will enhance diagnostic evaluation.

Central airway pathology: clinic features, CT findings with pathologic and virtual endoscopy correlation

Objectives

To describe the imaging features of the central airway pathology, correlating the findings with those in pathology and virtual endoscopy. To propose a schematic and practical approach to reach diagnoses, placing strong emphasis on multidetector computed tomography (MDCT) findings.

Methods

We reviewed our thoracic pathology database and the central airway pathology-related literature. Best cases were selected to illustrate the main features of each disease. MDCT was performed in all cases. Multiplanar and volume-rendering reconstructions were obtained when necessary. Virtual endoscopy was obtained from the CT with dedicated software.

Results

Pathological conditions affecting the central airways are a heterogeneous group of diseases. Focal alterations include benign neoplasms, malignant neoplasms, and non-neoplastic conditions. Diffuse abnormalities are divided into those that produce dilation and those that produce stenosis and tracheobronchomalacia. Direct bronchoscopy (DB) visualises the mucosal layer and is an important diagnostic and therapeutic weapon. However, assessing the deep layers or the adjacent tissue is not possible. MDCT and post-processing techniques such as virtual bronchoscopy (VB) provide an excellent evaluation of the airway wall.

Conclusion

This review presents the complete spectrum of the central airway pathology with its clinical, pathological and radiological features.

Teaching points

• Dividing diseases into diffuse and focal lesions helps narrow the differential diagnosis.

• Focal lesions with nodularity are more likely to correspond to tumours.

• Focal lesions with stenosis are more likely to correspond to inflammatory disease.

• Posterior wall involvement is the main feature in diffuse lesions with stenosis.

Case report: Castleman's disease in trachea

Castleman’s disease (CD) in trachea is rarely reported to date. This report introduces a case of CD in trachea with emphasis on its radiological presentation onCT. A female patient was admitted at our emergency department with dyspnoea. Plain and enhanced CT revealed a mass with distinct border and marked enhancement. Tracheotomy was planned and it turned out to be CD of hyaline type on pathological examination. Two similar case reports on intratracheal CD from 1954 to 2015 were reviewed as we searched in PubMed using key words “endotracheal Castleman’s disease” or “Castleman’s disease in trachea” or “Castleman’s disease in tracheal”. This will be the third case report of CD in trachea in English literature. In this case report, the radiological appearance of CD on multiple imaging modes is reviewed. Lesions that should be taken into consideration in differential diagnosis are mentioned. The two main surgical methods for such lesions are briefly described.

Tracheobronchial tumors

Tumors of trachea and bronchi are uncommon and can occur in the form of benign or low- and high-grade malignant tumors. Although tracheobronchial tumors (TBTs) represent only 0.6% of all pulmonary tumors, they are clinically significant. Delays in diagnosis of these tumors commonly occur because the signs and symptoms caused by these tumors are nonspecific and chest radiographs are often considered unremarkable. Therefore, novel radiological techniques and better access to flexible bronchoscopy enable detection of larger number of TBT. The purpose of this article is to provide a review of tracheal and bronchial tumors and discuss significant aspects of the different TBT with focus on clinical manifestations and diagnostic procedures.

Multi-detector computed tomography imaging of large airway pathology: A pictorial review

The tracheobronchial tree is a musculo-cartilagenous framework which acts as a conduit to aerate the lungs and consequently the entire body. A large spectrum of pathological conditions can involve the trachea and bronchial airways. These may be congenital anomalies, infections, post-intubation airway injuries, foreign body aspiration or neoplasms involving the airway. Appropriate management of airway disease requires an early and accurate diagnosis. In this pictorial essay review, we will comprehensively describe the various airway pathologies and their imaging findings by multi-detector computed tomography.

Imaging of Large Airways Disorders

OBJECTIVE

Recent technical advances, including the routine use of CT thin sections and techniques such as 2D minimum-intensity-projection and 3D volume images, have increased our ability to detect large airways diseases. Furthermore, dedicated CT protocols allow the evaluation of dynamic airway dysfunction.

CONCLUSION

With diseases of the large airways more commonly seen in daily practice, it is important that radiologists be familiar with the appearances, differential diagnosis, and clinical implications of these entities.

Bronchiectasis: Mechanisms and Imaging Clues of Associated Common and Uncommon Diseases

Bronchiectasis is permanent irreversible dilatation of the airways and occurs in a variety of pathologic processes. Recurrent infection and inflammation and the resulting chemical and cellular cascade lead to permanent architectural changes in the airways. Bronchiectasis can confer substantial potential morbidity, usually secondary to recurrent infection. In severe cases of bronchiectasis, massive hemoptysis can lead to death. Thin-section computed tomography is the most sensitive imaging modality for the detection of bronchiectasis; findings include bronchial diameter exceeding that of the adjacent pulmonary artery and lack of normal tapering of terminal bronchioles as they course toward the lung periphery. The authors will review various causes of bronchiectasis, including common causes, such as recurrent infection or aspiration, and uncommon causes, such as congenital immunodeficiencies and disorders of cartilage development. The authors will also present an approach emphasizing the distribution (apical versus basal and central versus peripheral) and concomitant findings, such as nodules, cavities, and/or lymphadenopathy, that can assist in narrowing the differential diagnosis. Although an adequate understanding of these underlying causes in conjunction with their specific imaging appearances will allow radiologists to more confidently determine the process causing this common radiologic finding, clinical history and patient demographic characteristics play an integral role in determining a pertinent and concise differential diagnosis.

Imaging of the central airways with bronchoscopic correlation: pictorial essay

A wide variety of pathologic processes, both benign and malignant, affect the central airways. These processes may be classified into 4 distinct groups: anatomic variants, lesions that result in focal or diffuse airway narrowing, and those that result in multinodular airway disorder. Key to the accurate assessment of the central airways is meticulous imaging technique, especially the routine acquisition of contiguous high-resolution, 1-mm to 1.5-mm images. These images enable high-definition axial, coronal, and sagittal reconstructions, as well as advanced imaging techniques, including minimum intensity projection images and virtual bronchoscopy. Current indications most commonly include patients presenting with signs and symptoms of possible central airway obstruction, with or without hemoptysis. In addition to diagnosing airway abnormalities, computed tomography (CT) also serves a critical complementary role to current bronchoscopic techniques for both diagnosing and treating airway lesions. Advantages of CT include noninvasive visualization of the extraluminal extent of lesions, as well as visualization of airways distal to central airways obstructions. As discussed and illustrated later, thorough knowledge of current bronchoscopic approaches to central airway disease is essential for optimal correlative CT interpretation.