Mucoepidermal carcinoma of the lung detected by positron emission tomography in a 5-year-old girl

Pulmonary Mucoepidermoid Carcinoma Mimicking Carcinoid Lung on 18 F-FDG and 68 Ga-DOTANOC PET/CT

ABSTRACT

Pulmonary mucoepidermoid carcinoma (PMEC) is a rare pulmonary neoplasm. Although 18 F-FDG PET/CT has been shown to present with increased metabolic activity in PMEC, literature does not report increased somatostatin receptor expression in these tumors. We present the case of a 15-year-old boy where PMEC mimicked a typical carcinoid of the lung on DOTANOC PET/CT by showing significant uptake on 68 Ga-DOTANOC.

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.

Role of fluorine-18-fluorodeoxyglucose positron emission tomography-computed tomography in management of pulmonary mucoepidermoid carcinomas and review of literature

Pulmonary mucoepidermoid carcinoma (PMEC) is a rare tumor of bronchial gland origin with a striking resemblance to MEC of the salivary glands. The World Health Organization classifies PMECs as "salivary gland type" tumors along with pulmonary adenoid cystic carcinomas and epimyoepithelial lung carcinomas. Their description in literature is largely limited to a few case series/case reports. Further, the experience of imaging in these tumors with fluorine-18 fluorodeoxyglucose positron emission tomography-computed tomography ( (18)F-FDG PET-CT) is also limited and evolving largely due to rarity of PMEC. We recently managed an interesting case of a PMEC and reviewed the literature surrounding this rare tumor with an emphasis on the role of (18)F-FDG PET-CT in its management. An (18)F-FDG PET-CT appears to be a useful imaging modality for predicting the tumor grade of patients with PMECs; further, there is emerging data to suggest the role of (18)F-FDG PET-CT for predicting the long-term prognosis of patients with PMEC.

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 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.

PET/CT in the Evaluation of Neuroblastoma

I-123-metaiodobenzylguanidine (MIBG) is the most commonly used functional imaging agent in patients with neuroblastoma, but use of [F-18]- FDG PET is increasing. MIBG is useful for defining the extent of disease at diagnosis, following response to treatment, and localizing residual and recurrent disease. In early-stage disease, FDG is often better concentrated in tumor sites than MIBG. In all stages, disease extent in the chest, abdomen, and pelvis and local metastases may be better delineated by FDG. In advanced-stage disease, MIBG is superior for following the treatment response of metastatic tumor in the marrow and bone. Several C-11- and F-18-labeled tracers may be equal to or superior to I-123-MIBG if supply problems can be resolved.

Mucoepidermoid carcinoma of the lung: High-resolution CT and histopathologic findings in five cases

OBJECTIVE

The purpose of this study was to characterize the high-resolution computed tomography (HRCT) findings of mucoepidermoid carcinoma of the lung and correlate them with the histopathological features.

METHODS

The study included five patients with pathologically proven mucoepidermoid carcinoma who underwent HRCT before treatment. The HRCT findings were then compared with the histopathological features in all patients.

RESULTS

The HRCT images showed lesions in the central lung in four patients and in the peripheral lung in one. All the lesions were well defined nodules or masses with a smooth margin. The contour of the tumours was oval (n=3), round (n=1) or lobulated (n=1). The contrast-enhanced CT images showed marked heterogeneous enhancement with foci of relatively low attenuation in four of the five lesions and mild heterogeneous enhancement in the other lesion. There was an admixed distribution of areas that are heterogeneous in the densities of blood vessels, as highlighted by immunohistochemical staining of CD31. Most mucin-secreting areas of the tumours showed more densely distributed blood vessels, mostly capillaries, in between tumour cell nests, whereas other areas did less. All five patients in our series underwent lobectomy plus lymph node dissection or sampling. All the patients are alive without evidence of disease an average of 50.4 months after surgery (range, 15-82 months; median, 57 months).

CONCLUSION

Mucoepidermoid carcinoma of the bronchus is often visualized as marked heterogeneous contrast enhancement on HRCT images. The results of this study suggest that the presence of abundant microvessels, detected immunohistochemically by microscopic examination, affects the enhancement pattern on HRCT.

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

In children, primary neoplasms of the tracheobronchial tree and lungs are rare; most are malignant. Of the primary malignant pulmonary neoplasms arising in childhood, mucoepidermoid carcinoma accounts for approximately 10%. Due to its well-confined local growth within the airway, mucoepidermoid carcinoma commonly produces respiratory symptoms from progressive tracheal or bronchial obstruction. Mucoepidermoid tumor has minimal metastatic potential in children, and local resection alone is the current treatment of choice. Early detection, diagnosis, and surgical resection of mucoepidermoid tumor are especially important in pediatric patients since the bulk of the remaining pulmonary parenchyma can be preserved, thereby decreasing the thoracic deformity and pulmonary functional morbidity. Radiographic and CT imaging findings of bronchial mucoepidermoid carcinoma in children have been described in several case reports. However, to the best of our knowledge, imaging findings of 2-((18)F)-fluoro-2-deoxy-D: -glucose positron emission tomography ((18)F-FDG PET) of mucoepidermoid carcinoma of the bronchus in pediatric patients have not been well established. We report a mucoepidermoid carcinoma arising from the right upper lobe bronchus in a 15-year-old girl with an emphasis on the (18)F-FDG PET findings.

PET and PET/CT in pediatric oncology

18F-fluorodeoxyglucose positron emission tomography (FDG-PET) and FDG-PET/computed tomography (CT) are becoming increasingly important imaging tools in the noninvasive evaluation and monitoring of children with known or suspected malignant diseases. In this review, we discuss the preparation of children undergoing PET studies and review radiation dosimetry and its implications for family and caregivers. We review the normal distribution of 18F-fluorodeoxyglucose (FDG) in children, common variations of the normal distribution, and various artifacts that may arise. We show that most tumors in children accumulate and retain FDG, allowing high-quality images of their distribution and pathophysiology. We explore the use of FDG-PET in the study of children with the more common malignancies, such as brain neoplasms and lymphomas, and the less-common tumors, including neuroblastomas, bone and soft-tissue sarcomas, Wilms' tumors, and hepatoblastomas. For comparison, other PET tracers are included because they have been applied in pediatric oncology. Multiple multicenter trials are underway that use FDG-PET in the management of children with neoplastic disease; these studies should give us greater insight into the impact FDG-PET can make in their care. PET is emerging as an important diagnostic imaging tool in the evaluation of pediatric cancers. The recent advent of dual-modality PET-computed tomography (PET/CT) imaging systems has added unprecedented diagnostic capability by revealing the precise anatomical localization of metabolic information and metabolic characterization of normal and abnormal structures. The use of CT transmission scanning for attenuation correction has shortened the total acquisition time, which is an especially desirable attribute in pediatric imaging. Moreover, expansion of the regional distribution of the most common PET radiotracer, FDG, and the introduction of mobile PET units have greatly increased access to this powerful diagnostic imaging technology. Here, we review the clinical applications of PET and PET/CT in pediatric oncology. General considerations in patient preparation and radiation dosimetry will be discussed.

F-18 FDG PET/CT imaging of low-grade mucoepidermoid carcinoma of the bronchus

Mucoepidermoid carcinomas in the bronchial tree are extremely rare tumors. Such tumors are classified into low-grade and high-grade on the basis of histological criteria. Fluorine-18-fluorodeoxyglucose positron emission tomography (F-18 FDG PET) is a useful technique for the evaluation of pulmonary lesions; however, to our knowledge, F-18 FDG PET findings in mucoepidermoid carcinoma of the bronchus have been described in only a few cases. Identifiable focal F-18 FDG uptake has been reported in high-grade mucoepidermoid carcinoma, but it is unclear whether F-18 FDG accumulates in low-grade mucoepidermoid carcinoma. Here, we present the case of a 37-year-old woman, with pathologically proven low-grade mucoepidermoid carcinoma, who underwent high-resolution computed tomography (CT) and F-18 FDG PET/CT before treatment.