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

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.

Correlation between 18-FDG standardized uptake value and tumor grade in patients with resectable non-small cell lung cancer

Background

Positron-emission tomography (PET) is widely used for staging lung cancer. Although a correlation between the fluorodeoxyglucose standardized uptake value (SUV) and the histologic grade of the tumor has been shown in several studies, little is known about the impact of different clinical variables on this correlation. This study aimed to evaluate the correlation between tumor SUV and tumor grade in a large cohort of patients and to analyse the impact of clinical factors on this correlation.

Methods

This retrospective cohort study including patients with non-small cell lung cancer age 18-90 years, with clinical stage I-IVA, who underwent curative-intent lung resection.

Results

Data from 726 patients was included in this study. There was a strong correlation between SUV and primary tumor grade in the whole cohort (P<0.001), which was significant in both sexes (P<0.001) and in all selected age groups (P<0.001-0.03). There was a significant SUV-grade correlation for the right upper and left lower lobes, as well as for the central location in the right lung (P<0.001, P=0.005 and P=0.04, respectively). Moreover, a significant SUV-grade correlation was found for squamous cell cancer and adenocarcinoma (P<0.001 and P=0.01, respectively), and for T1-T3 factors (P<0.001, P=0.006, P=0.005 respectively).

Conclusions

In patients with resectable lung cancer, a significant correlation was observed between the SUV of the primary tumor and its grade. This correlation was maintained for both sexes, age groups, most common histological types and T factors T1-T3.

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.

Pulmonary Salivary Gland Tumor, Mucoepidermoid Carcinoma: A Literature Review

Pulmonary mucoepidermoid carcinoma (PMEC) is the most common malignant salivary gland tumor in the lungs and accounts for 0.1-0.2% of all lung malignancies in adults. It has no specific epidemiological or clinical characteristics. Correct diagnosis requires the combined examinations of images, laboratories, pathology, and immunohistochemistry (IHC) as well as molecular characteristics. PMEC tumors are characterized by squamous, intermediate, and mucus-secreting cells. Currently, histological appearance, mitotic frequency, cellular atypia, and necrocytosis allow the classification of PMEC into low grade or high grade. Molecular changes are crucial to pathological diagnosis. The driver of PMEC seems to be the fusion protein MECT1-MAML2 that is generated from a genetic mutation in t (11; 19) (q21; p13), while other gene mutations are also reported. However, no treatment of PMEC exists so far; surgical excision is still the primary treatment, while the efficacies of chemotherapy or radiotherapy are undefined. Tyrosine kinase inhibitor (TKI) therapy and immunotherapy showed to have significant therapeutic effects but require more investigation and better understanding. This review focuses on the clinical characteristics, imaging and pathologic features, immunohistochemical examination, mutation analysis, differential diagnosis, prognosis, and treatment of PMEC.

Rapid metastasis of stage IA primary pulmonary high-grade mucoepidermoid carcinoma with a cystic airspace: a case report and reflection

Primary pulmonary high-grade mucoepidermoid carcinoma (MEC) with a cystic airspace is uncommon, and early metastasis is extremely rare. In such cases, however, it is clinically important for clinicians to consider whether the tumor has spread to the lymph nodes through the cystic airspace. A 77-year-old man presented to our hospital with cough and hemoptysis. Chest computed tomography showed a 25-mm-diameter mass with a cystic airspace located in the upper lobe of the left lung. The possibility of malignancy was considered. Without a definitive preoperative diagnosis, left upper lobectomy and mediastinal lymphadenectomy were performed. Histopathological examination revealed the typical histological characteristics of high-grade MEC (stage IA) and no lymph node metastasis. However, lymph node metastasis was found 6 months after surgical resection, and radiochemotherapy was performed. The patient developed widespread metastatic disease 4 months following completion of radiochemotherapy and died 2 months later. Primary pulmonary MEC with a cystic airspace is a rare malignant disease with uncommon imaging findings. Complete surgical resection is the main treatment method for high-grade MEC. In this case, we hypothesize that early metastasis was caused by seeding of tumor cells through the cystic airspace.

Mucoepidermoid carcinoma of the head and neck: CRTC1/3 MAML 2 translocation and its prognosticators

PURPOSE

Mucoepidermoid carcinoma (MEC) of the head and neck is a prevalent malignant salivary gland tumour with a reported good outcome. The aim of this study was to report the outcome in our centre.

METHODS

A retrospective chart analysis with survival analyses was performed combined with fluorescence in situ hybridization (FISH) analysis to assess CRTC1/3 MAML 2 fusion gene presence.

RESULTS

Sixty-four cases of MEC were identified. Median age at presentation was 51.4 years with a predominance for parotid gland involvement. Five, 10- and 20- year disease-free survival was 98%, 90% and 68%, respectively. Overall survival was 94%, 90% and 64%, respectively. Local recurrence was seen up to 14 years after primary diagnosis; distant metastases were diagnosed up to 17 years later. The overall recurrence rate was less than 20 per cent. CRTC1/3 MAML 2 fusion gene presence showed no survival benefit.

CONCLUSION

MEC of the head and neck has a favorable outcome with the exception of high-grade MEC. PNI and nodal involvement are not rare. CRTC1/3 MAML 2 fusion gene presence showed no survival benefit. The tendency for late onset of loco-regional and distant recurrence should not be underestimated.

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.

Different effects of bronchoscopic interventions on children and adults with tracheobronchial mucoepidermoid carcinoma

AIMS

To investigate the efficacy and safety of minimally invasive bronchoscopic interventions for patients with tracheobronchial mucoepidermoid carcinoma (MEC).

METHODS

Patients with tracheobronchial MEC were included in this retrospective study, and the clinical features, histologic grading, treatments, and cumulative survival rates were calculated. Patients were categorized into child (n = 16) and adult (n = 19) group according to their ages. Histologic grading, treatments, and survival status were compared between the two groups.

RESULTS

In pathology, high-grade MEC counts for 6.77% and 42.10% in the child and adult group, respectively. As tumor growth pattern was concerned, 93.33% and 21.05% tumors in the child and adult group present intratracheal type. Multiple bronchoscopic interventions were conducted, including rigid bronchoscopy, argon plasma coagulation (APC), dioxide carbon cryotherapy, and electric loop. Tumors could be removed by multiple bronchoscopic interventions. Bronchoscopy-associated complications were rare, including an oral mucosa injury and a glottis edema. In the child group, one patient underwent left upper lung lobectomy. In the adult group, lobectomy and/or chemotherapy and/or radiotherapy were conducted in seven patients. The 5-year survival rate was 100% and 68.90% in the child and the adult group, respectively.

CONCLUSIONS

Almost all children have low-grade and intratracheal MEC; 2/5 adults have invasive high-grade MEC. Multiple bronchoscopic interventions are effective in erasing low-grade intratracheal MEC without severe complications. For high-grade invasive MEC, aggressive and comprehensive therapy should be considered.

Challenges in diagnosis of pulmonary mucoepidermoid carcinoma: A case report

RATIONALE

Pulmonary mucoepidermoid carcinomas (PMECs) of the lung are rare malignant tumors. Despite progresses in examinations, the tumor represents a diagnostic challenge for pathologists and clinical physicians. Here, we present a patient who was eventually diagnosed with PMEC by the bronchoscopic examinations conducted three times.

PATIENT CONCERNS

We present the case of a 41-year-old female who was initially diagnosed with pulmonary pleomorphic adenoma (PPA) with a 68 × 82 mm mass and nodules in her lung and eventually diagnosed with PMEC.

DIAGNOSES

Based on histopathology, immunohistology, and imaging studies, the patient was diagnosed with PMEC (pT4N2M1).

INTERVENTIONS

The patient received first-line systemic chemotherapy regime (gemcitabine combined with carboplatin).

OUTCOMES

The patient received 2 cycles of chemotherapy. Based on the response evaluation criteria in solid tumor, she achieved partial response, and the mass was distinctly decreased from 68 × 22 mm to 41 × 17 mm.

LESSONS

This case presents a rare PMEC overlapping with PPA, based on histological findings, suggesting that besides imaging studies and laboratory examinations, multiple biopsies and ThinPrep cytology tests are necessary to obtain an accurate diagnosis. The patient showed positive response to chemotherapy.

Rare cause of lung atelectasis in a young woman

Pulmonary mucoepidermoid carcinoma is an extremely rare intrathoracic malignancy, comprising less than 1% of all lung tumours. These are very slow growing and are classified into low grade and high grade based on histological features. Surgical resection is the primary treatment with excellent outcomes, while chemotherapy or radiotherapy effectiveness is not known. Preoperative fluorine-18 fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) is useful for predicting tumour grade and postsurgical prognosis.A clinical case of a 31-year-old woman who presented with dyspnoea on exertion, cough and wheezing is reported. Imaging studies revealed a mass involving the left lower lobe bronchus and atelectasis. 18F-FDG PET/CT showed uptake in the described mass with a maximum standardised uptake value of 9.7. Complete surgical resection was performed, and pathological examination revealed a high-grade mucoepidermoid carcinoma with tumour-free margins. Adjuvant chemotherapy was given and there is no evidence of tumour recurrence.

A Radiomics Signature in Preoperative Predicting Degree of Tumor Differentiation in Patients with Non-small Cell Lung Cancer

RATIONALE AND OBJECTIVES

Poorly differentiated non-small cell lung cancer (NSCLC) indicated a poor prognosis and well-differentiated NSCLC indicates a noninvasive nature and good prognosis. The purpose of this study was to build and validate a radiomics signature to predict the degree of tumor differentiation (DTD) for patients with NSCLC.

MATERIALS AND METHODS

A total of 487 patients with pathologically diagnosed NSCLC were retrospectively included in our study. Five hundred ninety-one radiomics features were extracted from each tumor from the contrast-enhanced computed tomography images. A minimum redundancy maximum relevance algorithm and a logistic regression model were used for dimension reduction, feature selection, and radiomics signature building. The performance of the radiomics signature was assessed using receiver operating characteristic analysis, and the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy were calculated to quantify the association between a signature and DTD. An independent validation set contained 184 consecutive patients with NSCLC.

RESULTS

A nine-radiomics-feature-based signature was built and it could differentiate low and high DTDs in the training set (AUC = 0.763, sensitivity = 0.750, specificity = 0.665, and accuracy = 0.687), and the radiomics signature had good discrimination performance in the validation set (AUC = 0.782, sensitivity = 0.608, specificity = 0.752, and accuracy = 0.712).

CONCLUSIONS

A radiomics signature based on contrast-enhanced computed tomography imaging is a potentially useful imaging biomarker for differentiating low from high DTD in patients with NSCLC.

Comparison of different automated lesion delineation methods for metabolic tumor volume of 18F-FDG PET/CT in patients with stage I lung adenocarcinoma

The aim of the study was to investigate the suitable segmentation method in small, low uptake and heterogeneous nodules of stage I lung adenocarcinoma.133 stage I lung adenocarcinoma patients with F-FDG PET/CT scans were enrolled in this retrospective study. All lesions were divided into different groups according to nodule density, nodule size, and the maximum standard uptake value (SUVmax) level. Four different PET segmentation methods were performed, including percentage threshold of SUVmax (T42% and T42% × RC), gradient-based threshold (adaptive iterative algorithm, AT-AIA), and background-related threshold (adaptive thresholding at 40% SUVmax, AT40%) approaches. The MTVs were evaluated and compared with CT volume (CTV). Percentage volume error (%VE) compared to CTV was calculated and the correlations between MTVs and CTV were analyzed.AT-AIA had the highest accuracy in large, high uptake, and solid nodules (72.5%, 72.4%, and 65.6%, respectively). AT40% had the highest accuracy in small, low uptake and nonsolid nodules (56.6%, 56.1%, and 62.6%, respectively). In part-solid nodules, the accuracy of AT-AIA (60.0%) and AT40% (56.7%) were higher than that of T42% and T42% × RC. The MTV of AT-AIA was in excellent correlation with the CTV in solid nodules (R = 0.831, P < .001) and in high uptake nodules (R = 0.830, P < .001). The MTV of AT40% was in good correlation with the CTV in nonsolid nodules (R = 0.686, P = .003) and in part-solid nodules (R = 0.731, P < .001).AT40% showed best performance in small, low uptake, nonsolid and part-solid lesions. AT-AIA was suitable for large, high uptake, and solid lesions.

Selection and Reporting of Statistical Methods to Assess Reliability of a Diagnostic Test: Conformity to Recommended Methods in a Peer-Reviewed Journal

Objective

To evaluate the frequency and adequacy of statistical analyses in a general radiology journal when reporting a reliability analysis for a diagnostic test.

Materials and Methods

Sixty-three studies of diagnostic test accuracy (DTA) and 36 studies reporting reliability analyses published in the Korean Journal of Radiology between 2012 and 2016 were analyzed. Studies were judged using the methodological guidelines of the Radiological Society of North America-Quantitative Imaging Biomarkers Alliance (RSNA-QIBA), and COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) initiative. DTA studies were evaluated by nine editorial board members of the journal. Reliability studies were evaluated by study reviewers experienced with reliability analysis.

Results

Thirty-one (49.2%) of the 63 DTA studies did not include a reliability analysis when deemed necessary. Among the 36 reliability studies, proper statistical methods were used in all (5/5) studies dealing with dichotomous/nominal data, 46.7% (7/15) of studies dealing with ordinal data, and 95.2% (20/21) of studies dealing with continuous data. Statistical methods were described in sufficient detail regarding weighted kappa in 28.6% (2/7) of studies and regarding the model and assumptions of intraclass correlation coefficient in 35.3% (6/17) and 29.4% (5/17) of studies, respectively. Reliability parameters were used as if they were agreement parameters in 23.1% (3/13) of studies. Reproducibility and repeatability were used incorrectly in 20% (3/15) of studies.

Conclusion

Greater attention to the importance of reporting reliability, thorough description of the related statistical methods, efforts not to neglect agreement parameters, and better use of relevant terminology is necessary.

Comparison of novel multi-level Otsu (MO-PET) and conventional PET segmentation methods for measuring FDG metabolic tumor volume in patients with soft tissue sarcoma

BACKGROUND

We have previously developed a novel and highly consistent PET segmentation algorithm using a multi-level Otsu method (MO-PET). The aim of this study was to evaluate the reliability of MO-PET compared to conventional PET segmentation methods for measuring 18F-FDG (FDG) PET metabolic tumor volume (MTV) in patients with soft tissue sarcoma (STS). Clinical and imaging data were obtained from the Cancer Imaging Archive. Forty-eight STS patients with FDG PET/CT and MR prior to therapy were analyzed. MTV of the tumor using MO-PET was compared to other conventional methods (absolute SUV threshold values of 2.0, 2.5, or 3.0 and percentage of tumor SUVmax values of 30, 40, 50, or 60%) and gradient-based method (PET Edge™). The reference volume was defined as an MR-based gross tumor volume (GTV). Spearman, intra-class correlation, and Bland-Altman analysis were performed to evaluate the correlation and agreement of MTV to GTV.

RESULTS

MTVs obtained using each conventional SUV parameter, PET Edge™, and MO-PET were highly correlated with the GTV in Spearman and intra-class correlation analysis (p < 0.05). MO-PET and PET Edge™ showed high intra-class correlation coefficient of MTV to GTV (0.93 and 0.84, respectively). The Bland-Altman bias results showed the highest agreement for MTV using MO-PET with GTV (26.0 ± 489.6 cm3) compared to other methods (SUV 2.0 with - 69.3 ± 765.8, 30% SUVmax with - 255.0 ± 876.6, and PET Edge™ with - 26.46 ± 668.82 cm3).

CONCLUSIONS

PET MTV segmented with MO-PET showed higher correlation and agreement with GTV in comparison to conventional percentage SUVmax and absolute SUV threshold-based PET segmentation methods. MO-PET is comparable to PET Edge™. MO-PET is a reliable and consistent method for measuring tumor MTV.

Surgical outcomes of pulmonary mucoepidermoid carcinoma: A review of 41 cases

INTRODUCTION

Pulmonary mucoepidermoid carcinoma is a rare cancer that occurs primarily in younger patients. The prognostic factors of pulmonary mucoepidermoid carcinoma are largely undetermined, especially in elderly patients. The aim of this study was to examine the clinical characteristics and prognostic factors influencing survival after surgical resection in patients with pulmonary mucoepidermoid carcinoma and also analyze the clinical manifestations and prognostic factors in elderly patients.

MATERIALS AND METHODS

The pathological records of 41 pulmonary mucoepidermoid carcinoma patients (mean age, 61.4 years) who underwent surgical resection at our hospital between January 1991 and July 2015 were retrospectively reviewed. Subjects >65 years of age (n = 22) were considered elderly.

RESULTS

The median follow-up duration was 42.9 (interquartile range, 15.0-120.8) months. Sixteen patients (39.0%) experienced tumor relapse, including 13 patients (81.3%) within 2 years. The 5-year disease-free survival rate was 57.9%. Tumor grade did not influence disease-free survival (P = 0.286). In the multivariate analysis, age, tumor size, pathological T3-4 status, and pathological N2 status were independent predictors of disease-free survival. The 5-year overall survival rate was 57.0%. Tumor grade also did not influence overall survival (P = 0.170). Age, tumor size, pathological T status, and pathological N2 status were independent predictors of overall survival. In elderly patients, the 5-year disease-free survival and overall survival rates were 41.4% and 41.5%, respectively. Pathological T status was the only independent predictor of both disease-free survival and overall survival in elderly patients.

CONCLUSIONS

Prognostic factors identified for pulmonary mucoepidermoid carcinoma in this study differ from those of previous studies. Principally, tumor grade did not influence either disease-free survival or overall survival. Age, tumor size, and pathological factors were independent predictors of disease-free survival and overall survival. In elderly patients, pathological T status was the only independent predictor of disease-free survival and overall survival.

Does the Reporting Quality of Diagnostic Test Accuracy Studies, as Defined by STARD 2015, Affect Citation?

Objective

To determine the rate with which diagnostic test accuracy studies that are published in a general radiology journal adhere to the Standards for Reporting of Diagnostic Accuracy Studies (STARD) 2015, and to explore the relationship between adherence rate and citation rate while avoiding confounding by journal factors.

Materials and Methods

All eligible diagnostic test accuracy studies that were published in the Korean Journal of Radiology in 2011–2015 were identified. Five reviewers assessed each article for yes/no compliance with 27 of the 30 STARD 2015 checklist items (items 28, 29, and 30 were excluded). The total STARD score (number of fulfilled STARD items) was calculated. The score of the 15 STARD items that related directly to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 was also calculated. The number of times each article was cited (as indicated by the Web of Science) after publication until March 2016 and the article exposure time (time in months between publication and March 2016) were extracted.

Results

Sixty-three articles were analyzed. The mean (range) total and QUADAS-2-related STARD scores were 20.0 (14.5–25) and 11.4 (7–15), respectively. The mean citation number was 4 (0–21). Citation number did not associate significantly with either STARD score after accounting for exposure time (total score: correlation coefficient = 0.154, p = 0.232; QUADAS-2-related score: correlation coefficient = 0.143, p = 0.266).

Conclusion

The degree of adherence to STARD 2015 was moderate for this journal, indicating that there is room for improvement. When adjusted for exposure time, the degree of adherence did not affect the citation rate.

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.