Mucoepidermoid carcinoma of bronchus in a pediatric patient: (18)F-FDG PET findings

Positron emission tomography in the diagnosis and management of primary pediatric lung tumors

Primary pediatric lung tumors are uncommon and have many overlapping clinical and imaging features. In contrast to adult lung tumors, these rare pediatric neoplasms have a relatively broad histologic spectrum. Informed by a single-institution 13-year retrospective record review, we present an overview of the most common primary pediatric lung neoplasms, with a focus on the role of positron emission tomography (PET), specifically 18F-fluorodeoxyglucose (FDG) PET and 68Ga-DOTATATE PET, in the management of primary pediatric lung tumors. In addition to characteristic conventional radiographic and cross-sectional imaging findings, knowledge of patient age, underlying cancer predisposition syndromes, and PET imaging features may help narrow the differential. While metastases from other primary malignancies remain the most commonly encountered pediatric lung malignancy, the examples presented in this pictorial essay highlight many of the important conventional radiologic and PET imaging features of primary pediatric lung malignancies.

Pulmonary mucoepidermoid carcinoma in children: two case reports and a review of the literature

Pulmonary mucoepidermoid carcinoma (PMEC) is a rare tumor, particularly in children, and its clinical manifestations vary. When the tumor is small, it may be asymptomatic; however, with larger tumors, patients may present with symptoms such as recurring pneumonia, atelectasis, persistent cough, chest pain, and even hemoptysis. PMEC appears as an exophytic intrabronchial mass. This study aims to report on the clinical manifestations, imaging findings, treatment approaches, and prognosis of two children diagnosed with PMEC at our hospital between January 2018 and December 2022. The age of onset for both children was 9 years, and the masses were located in the right upper lobe bronchi. Following surgical treatment, both patients showed a good prognosis. In addition, we conducted a comprehensive review of the relevant literature to enhance the overall understanding of PMEC.

Mucoepidermoid carcinoma of the bronchus in two children: Case reports

Childhood mucoepidermoid carcinomas (MEC) of the bronchus are rare. They present with non-specific symptoms and signs making diagnosis delayed. We present two children with bronchial MEC managed in a tertiary children's hospital in Cape Town, South Africa. The first was a 11-year male with recurrent haemoptysis and the second child was a 6-year female with recurrent unifocal pneumonia. Chest CT scan and bronchoscopy with biopsy confirmed the diagnosis. Both patients underwent treatment, including surgery and are doing well. It is important to exclude endobronchial lesions when children present with recurrent respiratory symptoms, since early diagnosis will enable lung-sparing treatment.

Mucoepidermoid carcinoma of the thymus incidentally diagnosed following two-years of non-productive cough

Mucoepidermoid carcinoma of the thymus is a rare primary thymic carcinoma. Radiologic imaging of this malignancy is rarely reported in literature. We present a patient who complained of a chronic cough for two years who was later found to have mucoepidermoid carcinoma of the thymus. Chest radiograph revealed a large anterior mediastinal mass. Follow-up computed tomography of the thorax demonstrated a large, heterogeneous anterior mediastinal mass with traversing vessels. F-18 fluorodeoxyglucose positron emission tomography-computed tomography demonstrated high avidity in the lesion with areas of diminished activity thought to represent necrosis. Following surgical resection, pathology revealed high-grade mucoepidermoid carcinoma of the thymus extending into the skeletal muscle and pericardium with evidence of lymphovascular invasion. The patient received external beam radiation therapy and has remained disease-free for three years.

Pediatric airway tumors: A report from the International Network of Pediatric Airway Teams (INPAT)

OBJECTIVE

Primary tracheobronchial tumors (PTTs) are rare heterogeneous lesions arising from any part of the tracheobronchial tree. Nonspecific symptoms may lead to delayed diagnosis that requires more aggressive surgical treatment. An analysis of cases collected by the International Network of Pediatric Airway Team was undertaken to ensure proper insight into the behavior and management of PTTs.

METHODS

Patients <18 years of age with a histological confirmation of PTT diagnosed from 2000 to 2015 were included in this multicenter international retrospective study. Medical records, treatment modalities, and outcomes were analyzed. The patient presentation, tumor management, and clinical course were compared between malignant and benign histotypes. Clinical and surgical variables that might influence event-free survival were considered.

RESULTS

Among the 78 children identified, PTTs were more likely to be malignant than benign; bronchial carcinoid tumor (n = 31; 40%) was the most common histological subtype, followed by inflammatory myofibroblastic tumor (n = 19; 25%) and mucoepidermoid carcinoma (n = 15; 19%). Regarding symptoms at presentation, wheezing (P = 0.001) and dyspnea (P = 0.03) were more often associated with benign growth, whereas hemoptysis was more frequently associated with malignancy (P = 0.042). Factors that significantly worsened event-free survival were age at diagnosis earlier than 112 months (P = 0.0035) and duration of symptoms lasting more than 2 months (P = 0.0029).

CONCLUSION

The results of this international study provide important information regarding the clinical presentation, diagnostic workup, and treatment of PTTs in children, casting new light on the biological behavior of PTTs to ensure appropriate treatments.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:E243-E251, 2020.

Interventional Bronchoscopic Therapy in Adult Patients with Tracheobronchial Mucoepidermoid Carcinoma

Background:

Tracheobronchial mucoepidermoid carcinoma (MEC) is a rare airway tumor in adults for which surgery is considered a first-line treatment. However, some patients already lost the best opportunity of a surgical intervention when diagnoses are confirmed, and surgery causes considerable trauma resulting in partial loss of pulmonary function. Moreover, the tumor is resistant to radiotherapy and chemotherapy. These factors make the treatment of tracheobronchial MEC challenging. This study aimed to evaluate the safety and efficacy of interventional bronchoscopic therapy in adult patients with tracheobronchial MEC.

Methods:

We retrospectively analyzed the clinical manifestations, bronchoscopic interventions, complications, and outcomes of 11 adult patients with tracheobronchial MEC. Paired t-test was used to analyze the parameters of the American Thoracic Society Dyspnea Index and the Karnofsky Score before and after the first interventional bronchoscopic therapy.

Results:

All tumors occurred in the main bronchus and were easily visualized by bronchoscopy. After interventional bronchoscopic therapy, the symptoms of all patients showed significant improvement. The American Thoracic Society Dyspnea Index decreased from 1.91 ± 1.22 to 0.27 ± 0.47 (t = 6.708, P < 0.001) and the Karnofsky Score increased from 78.18 ± 16.62 to 95.46 ± 8.20 (t = −5.190, P < 0.001). Bronchoscopic intervention did not result in serious complications or mortality. During the follow-up period between 3 and 96 months after the first therapy, the following results were noted: (1) among the eight patients with low-grade tracheobronchial MEC, only one patient had a relapse and agreed to surgical treatment; (2) among the three patients with high-grade tracheobronchial MEC, one patient required repeated bronchoscopic interventions, one patient died of pulmonary infection, and one patient died of systemic failure owing to tumor metastasis.

Conclusions:

Interventional bronchoscopic therapy, as an alternative treatment, shows promise in some adult patients with low-grade tracheobronchial MEC confined to the bronchus. However, for adult patients with high-grade tracheobronchial MEC, early diagnosis and surgical treatment are still strongly recommended.

18F-FDG PET/CT Imaging of Tracheal Mucoepidermoid Carcinoma

A 54-year-old woman presented with dry cough for 3 months. An FDG PET/CT was performed to evaluate a tracheal nodule, which was revealed by chest CT. The PET/CT images showed increased FDG uptake with SUVmax of 3.3 in the known tracheal lesion. The results of pathological examination from the specimen of bronchoscopy were consistent with tracheal mucoepidermoid carcinoma.

Mucoepidermoid Carcinoma of the Tracheobronchial Tree

Primary salivary type lung cancers are extremely rare intrathoracic malignancies. Mucoepidermoid tumor is one of the salivary gland tumors that originates from submucosal glands of the tracheobronchial tree. These are very slow-growing low-grade malignant tumors. Surgery is the mainstay of treatment and rarely requires adjuvant therapy. In this case report we describe a 65-year-old woman who presented with a solitary cough yet on further investigation was found to have a mucoepidermoid tumor originating from the hilum of the left lung.

Primary tracheobronchial tumors in children

Primary tracheobronchial tumors are rare lesions that can be benign or malignant, with different location along the airway tree. Symptoms may include wheezing, chronic pneumonia, asthma, chest pain, recurrent cough, atelectasis, haemoptysis, and weight loss. Due to the heterogeneity of symptoms, diagnosis can be difficult and the airway involvement can lead progressively to a bronchial or tracheal obstruction. Due to the rarity of primary tracheobronchial tumors in children, there are not any oncological guidelines on pre-operative work-up, treatment, and follow-up. Only few reports and multicentric studies are reported. In most cases, surgical resection seems to be the treatment of choice. Brachytherapy, endoscopic treatment, and chemotherapy are rarely described. In this article we present an overview on these rare tumors, including pathological aspects, clinical presentation, imaging assessment, and endoscopic or open surgical treatments. We discuss different surgical approaches, according with tumor location.

Childhood and adolescent tracheobronchial mucoepidermoid carcinoma (MEC): a case-series and review of the literature

Tracheobronchial mucoepidermoid carcinomas (MEC) are rare in the pediatric population with literature limited primarily to case reports. Here we present our institutional experience treating MEC in three patients and review the literature of 142 pediatric cases previously published from 1968 to 2013. Although rare, tracheobronchial MEC should be included in the differential diagnosis in a child with recurrent respiratory symptoms. Conservative surgical management is often sufficient to achieve complete resection and good outcomes.

Prediction of Pathologic Grade and Prognosis in Mucoepidermoid Carcinoma of the Lung Using ¹⁸F-FDG PET/CT

Objective

The maximum standardized uptake value (SUV_max) of pulmonary mucoepidermoid carcinoma (PMEC) in fluorine-18fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) was evaluated as a preoperative predictor of pathologic grade and survival rate.

Materials and Methods

Twenty-three patients who underwent preoperative PET/CT and complete resection for PMEC were enrolled. The optimal cut-off SUV_max for tumor grade was calculated as 6.5 by receiver operating characteristic curve. The patients were divided into a high SUV group (n = 7) and a low SUV group (n = 16). Clinicopathologic features were compared between the groups by χ² test and overall survival was determined by Kaplan-Meier analysis.

Results

The mean SUV_max was 15.4 ± 11.5 in the high SUV group and 3.9 ± 1.3 in the low SUV group. All patients except one from the low SUV group had low grade tumors and all had no nodal metastasis. The sensitivity and specificity of SUV_max from PET/CT for predicting tumor grade was 85.7% and 93.8%, respectively. During the follow-up period (mean, 48.6 ± 38.7 months), four patients from the high SUV group experienced cancer recurrence, and one died of cancer. In contrast, none of the low SUV group had recurrence or mortality. Five-year overall survival rate was significantly higher in the low SUV group (100% vs. 71.4%, p = 0.031).

Conclusion

Pulmonary mucoepidermoid carcinoma patients with high SUV_max in PET/CT had higher tumor grade, more frequent lymph node metastasis and worse long-term outcome. Therefore, PMEC patients with high uptake on PET/CT imaging might require aggressive mediastinal lymph node dissection and adjuvant therapies.

Role of 68Ga-DOTATOC PET/CT in initial evaluation of patients with suspected bronchopulmonary carcinoid

PURPOSE

The objective of this study was to evaluate the role of (68)Ga-DOTATOC positron emission tomography (PET)/CT scan in patients with suspected pulmonary carcinoid tumour and to compare its results with (18)F-fluorodeoxyglucose (FDG) PET/CT scan.

METHODS

In this prospective study, 32 patients (age 34.22 ± 12.03 years; 53.1 % female) with clinical suspicion of bronchopulmonary carcinoid were evaluated with (68)Ga-DOTATOC PET/CT and (18)F-FDG PET/CT. The two imaging modalities were compared, considering the tissue diagnosis as the reference standard.

RESULTS

Based on the reference standard 26 cases were carcinoid tumours [21 typical carcinoids (TC) and 5 atypical carcinoids (AC)] and 6 cases were non-carcinoid tumours. The sensitivity, specificity and accuracy of (68)Ga-DOTATOC PET/CT in the diagnosis of pulmonary carcinoid tumour were 96.15, 100 and 96.87 % respectively, whereas those of (18)F-FDG PET/CT were 78.26, 11.1 and 59.37 % respectively. The maximum standardised uptake value (SUV max) of TC on (68)Ga-DOTATOC PET/CT scan ranged from 3.58 to 55, while that of AC ranged from 1.1 to 32.5. (18)F-FDG PET/CT was true-positive in all cases of AC and false-negative in eight cases of TC (sensitivity for TC 61.9 % and for AC 100 %).

CONCLUSION

(68)Ga-DOTATOC PET/CT is a useful imaging investigation for the evaluation of pulmonary carcinoids. (18)F-FDG PET/CT scan suffers from low sensitivity and specificity in differentiating the pulmonary carcinoids from other tumours.

Primary lung and large airway neoplasms in children: current imaging evaluation with multidetector computed tomography

Multidetector computed tomography (MDCT) offers an important noninvasive imaging modality for confirmation and further characterization of primary lung and large airway neoplasms encountered in pediatric patients. Children represent a unique challenge in imaging, not only because of unique patient factors (eg, inability to follow instructions, motion, need for sedation) but because of the technical factors that must be optimized to reduce radiation dose. This article reviews an MDCT imaging algorithm, up-to-date imaging techniques, and clinical applications of MDCT for evaluating benign and malignant primary neoplasms of lung and large airway in infants and children.

Advanced large airway CT imaging in children: evolution from axial to 4-D assessment

Continuing advances in multidetector computed tomography (MDCT) technology are revolutionizing the non-invasive evaluation of congenital and acquired large airway disorders in children. For example, the faster scanning time and increased anatomical coverage that are afforded by MDCT are especially beneficial to children. MDCT also provides high-quality multiplanar 2-dimensional (2-D), internal and external volume-rendering 3-dimensional (3-D), and dynamic 4-dimensional (4-D) imaging. These advances have enabled CT to become the primary non-invasive imaging modality of choice for the diagnosis, treatment planning, and follow-up evaluation of various large airway disorders in infants and children. It is thus essential for radiologists to be familiar with safe and effective techniques for performing MDCT and to be able to recognize the characteristic imaging appearances of large airway disorders affecting children.

Multidetector computed tomography of pediatric large airway diseases: state-of-the-art

Advances in multidetector computed tomography (MDCT) technology have given rise to improvements in the noninvasive and comprehensive assessment of the large airways in pediatric patients. Superb two-dimensional and three-dimensional reconstruction MDCT images have revolutionized the display of large airways and enhanced the ability to diagnose large airway diseases in children. The 320-MDCT scanner, which provides combined detailed anatomic and dynamic functional information assessment of the large airways, is promising for the assessment of dynamic large airway disease such as tracheobronchomalacia. This article discusses imaging techniques and clinical applications of MDCT for assessing large airway diseases in pediatric patients.

Role of positron emission tomography-computed tomography in bronchial mucoepidermoid carcinomas: a case series and review of the literature

INTRODUCTION

Mucoepidermoid carcinoma of the tracheobronchial tree is rare. Such tumors usually present with signs and symptoms of bronchial obstruction. Histologically, they can be classified as high-grade or low-grade tumors. Experience of imaging these tumors with 18fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) is limited. We present three cases of this rare tumor, describe the functional imaging results, and review the available literature.

CASE PRESENTATION

Three Caucasian patients, two men (21 and 24 years of age) and one woman (14 years of age), with bronchial masses were evaluated by us. All three patients were symptomatic, and underwent a thorough clinical examination, bronchoscopy and biopsy, plain computed tomography, 18F-FDG PET-CT and 68Gallium 1,4,7,10-Tetraazacyclododecane-NI,NII,NIII,NIIII,- tetra acetic acid (D) - Phel1-Tyr3-octreotide positron emission tomography-computed tomography (68Ga-DOTATOC PET-CT). 18F-FDG PET-CT revealed mild uptake in all three patients, whereas 68Ga-DOTATOC PET-CT revealed no significant uptake in any patient, making carcinoid tumor unlikely. Results of histopathological examination were consistent with low-grade mucoepidermoid carcinoma in all patients.

CONCLUSION

Our study reveals that functional imaging may be helpful in the initial investigation of patients with mucoepidermoid carcinoma. 18F-FDG PET-CT may have a prognostic relevance by predicting the histopathologic differentiation of the tumor.

Primary lung tumors in children and adolescents: a 90-year experience

PURPOSE

Primary lung tumors in children are rare. A wide range of histopathologic tumor types occurs. The incidence of these lesions and their outcomes are still largely unknown. This study aims to determine the incidence of different primary lung tumors in children and to contribute data leading to the development of evidence-based treatment models.

METHODS

A single institution retrospective review was performed with institutional review board approval. Patients were included if they had primary, nonhematologic lung tumors. Simple squamous papillomas subjected to endoscopic biopsy and not resected, and vascular lesions associated with multisystem lesions, such as hereditary hemorrhagic telangiectasia, were excluded. Medical records and pathologic material for patients from 1918 to 2008 were reviewed.

RESULTS

Forty patients were identified (23 boys, 17 girls) with a mean age of 9.6 years (range, 3 months to 19 years). Fourteen distinct histopathologic tumor types were identified. The most common tumor types were carcinoid (8), inflammatory myofibroblastic tumor (7), and pleuropulmonary blastoma (6). Rare pediatric lung tumors including small cell carcinoma, adenocarcinoma, and pulmonary capillary hemangiomatosis were also seen. The mortality rate was 17.5% (7) in our series. Chemotherapy was used in 23% (9) and radiation in 20% (8) of the patients. Of the 33 survivors, 28 had follow-up with a median duration of 29.5 months (mean, 63.2 months; range, 1-471 months).

CONCLUSIONS

Primary lung tumors in children are rare and histopathologically diverse. The tumor spectrum involves many types not seen in adults, and unlike adults, patients rarely have a history of exposure to external predisposing factors. Although complete resection remains the standard for treatment of most tumors, addition of adjuvant therapy is dependent on both tumor stage and histopathologic type.

Tumors in the tracheobronchial tree: CT and FDG PET features

A variety of tumors, including primary malignant tumors, secondary malignant tumors, and benign tumors, can occur in the tracheobronchial tree. Primary malignant tumors commonly originate from the surface epithelium or the salivary glands, whereas most benign tumors arise from the mesenchymal tissue. At computed tomography (CT), primary malignant tumors manifest as a polypoid lesion, a focal sessile lesion, eccentric narrowing of the airway lumen, or circumferential wall thickening. At fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET), most squamous cell carcinomas show high uptake, whereas adenoid cystic carcinoma and mucoepidermoid carcinoma show variable uptake depending on the grade of differentiation. High-grade malignancies tend to show high and homogeneous uptake. Carcinoid tumors commonly show intense enhancement at contrast material-enhanced CT, which can be helpful in making the diagnosis, and usually have lower uptake at FDG PET than would be expected for a malignant tumor. Secondary malignant tumors occur as a result of either hematogenous metastasis or direct invasion by a malignancy from an adjacent structure. Their CT manifestations are similar to those of primary malignant tumors, with uptake at FDG PET depending primarily on the metabolic activity and degree of differentiation of the primary tumor. Among the benign tumors, hamartoma and lipoma can show characteristic CT findings such as "popcorn" calcification or internal fat. However, CT findings in most benign tumors are nonspecific. At FDG PET, benign tumors usually show little or no uptake and can be differentiated from malignant tumors. Knowledge of the characteristic CT and FDG PET findings of tracheobronchial tumors can aid in diagnosis and treatment planning.

[Malignant pulmonary tumors in children]

Pulmonary neoplasms in children are rare. The majority of tumors involving the respiratory system are metastatic and primary lung tumors are even more rare. Approximately 75% of primary lung tumors are malignant, the most frequent of which are adenoma, bronchogenic carcinoma, and pleuropulmonary blastoma. Due to the rarity of these malignancies, and the usually nonspecific clinical symptoms, they are often not considered in the differential diagnosis in children who present with persistent pneumonitis, coughing, and atelectasis. This often results in delayed definitive treatment and, in general, a worse prognosis. The role of the radiologist is that by using modern imaging techniques, to facilitate early recognition and staging, enabling adequate treatment and follow-up and thus, a better clinical prognosis. This article provides an overview of the most relevant entities of primary childhood pulmonary malignancies, with a particular emphasis on the imaging characteristics.