Computed Tomography Imaging of Anterior and Middle Mediastinal Ewing Sarcoma/Primitive Neuroectodermal Tumors

Primary mediastinal Ewing's sarcoma presenting with sudden and severe chest pain: a case report

Ewing's sarcoma, characterized by small round cell morphology, is a rare malignancy, with mediastinal Ewing's sarcoma being even less common. This case describes a distinctive presentation of primary mediastinal Ewing's sarcoma in a 32-year-old male presenting with sudden and severe chest pain. Initial evaluation excluded cardiac and pulmonary emergencies, revealing a posterior mediastinal mass through advanced imaging. The patient's clinical symptoms significantly improved following the complete resection of the tumor via thoracoscopy. Subsequent analysis incorporating imaging, histological, immunohistochemical and genetic findings led to the conclusive diagnosis of primary mediastinal Ewing's sarcoma.

Mesenchymal Tumors of the Mediastinum: An Update on Diagnostic Approach

Mesenchymal tumors of the mediastinum are a heterogenous group of rare tumors with divergent lineages. Mediastinal mesenchymal tumors are diagnostically challenging due to their diversity and morphologic overlap with nonmesenchymal lesions arising in the mediastinum. Accurate histologic diagnosis is critical for appropriate patient management and prognostication. Many mediastinal mesenchymal tumors affect distinct age groups or occur at specific mediastinal compartments. Neurogenic tumors, liposarcoma, solitary fibrous tumor, and synovial sarcoma are common mesenchymal tumors in the mediastinum. Herein, we provide an update on the diagnostic approach to mediastinal mesenchymal tumors and a review of the histologic features and differential diagnosis of common benign and malignant mesenchymal tumors of the mediastinum.

Diagnostic accuracy of multidetector computed tomography scan in mediastinal masses assuming histopathological findings as gold standard

Purpose

Aim of the study was to: 1) present MDCT characteristics of different mediastinal mass lesions, 2) estimate proportion of benign and malignant mediastinal mass lesions based on MDCT findings, and 3) find out the diagnostic accuracy with sensitivity, specificity, positive predictive value, and negative predictive value of MDCT in mediastinal mass lesions assuming histopathology as gold standard.

Material and methods

This study was an analysis of 60 patients who underwent MDCT scan for characterisation of mediastinal mass lesion, and subsequently imaging findings were verified with pathological diagnosis.

Results

Out of 60 patients 65% were malignant and 35% were benign. Metastatic carcinoma was the leading diagnosis. Sensitivity of MDCT in this study came out to be 94%, specificity is 90%, with a positive predictive value of 94% and negative predictive value of 90% with diagnostic accuracy of 93%.

Conclusions

Mediastinal mass lesion can be accurately diagnosed with MDCT which is a non-invasive and easily available modality requiring clinical data for accurate diagnosis and management. Co-relation of MDCT findings with other imaging findings is complex and requires adequate clinical data for optimum diagnostic confidence.

Multiple Ewing Sarcoma/Primitive Neuroectodermal Tumors in the Mediastinum: A Case Report and Literature Review

Ewing sarcoma/primitive neuroectodermal tumors (ES/PNET) are high-grade malignant neoplasms. These malignancies present very rare tumors of thoracopulmonary area and even rarer in the mediastinum. In our knowledge, ES/PNET presented with multiple mediastinal masses has not been reported previously. We experienced a case of a 42-year-old man presented with gradual onset of left-side pleuritic chest pain. A contrast-enhanced chest computed tomography (CT) scan showed separate 2 large heterogeneously enhancing masses in each anterior and middle mediastinum of the left hemithorax. Positron emission tomography-computed tomography (PET-CT) scan revealed high fluorodeoxyglucose (FDG) uptake in the mediastinal masses. After surgical excision for the mediastinal masses, both of the masses were diagnosed as the ES/PNET group of tumors on the histopathologic examination. The patient refused postoperative adjuvant chemotherapy and came back with local tumor recurrence and distant metastasis on 4-month follow-up after surgical resection. We report this uncommon form of ES/PNET. We are to raise awareness that this rare malignancy should be considered as a differential diagnosis of the malignant mediastinal tumors and which can be manifested as multiple masses in a patient. Understanding this rare entity of extra-skeletal ES/PNET and characteristic imaging findings can help radiologists and clinicians to approach proper diagnosis and better management for this highly malignant tumor.

Mesenchymal tumours of the mediastinum--part II

This is the second part of a two-part review on soft tissue tumours which may be encountered in the mediastinum. This review is based on the 2013 WHO classification of soft tissue tumours and the 2015 WHO classification of tumours of the lung, pleura, thymus and heart and provides an updated overview of mesenchymal tumours that have been reported in the mediastinum.

Askin tumor: CT and FDG-PET/CT imaging findings and follow-up

The aim of the study was to describe the imaging findings of Askin tumors on computed tomography (CT) and fluorine 18 fluorodeoxyglucose-positron emission tomography (FDG-PET/CT).Seventeen cases of Askin tumors confirmed by histopathology were retrospectively analyzed in terms of CT (17 cases) and FDG-PET/CT data (6 cases).Fifteen of the tumors were located in the chest wall and the other 2 were in the anterior middle mediastinum. Of the 15 chest wall cases, 13 demonstrated irregular, heterogeneous soft tissue masses with cystic degeneration and necrosis, and 2 demonstrated homogeneous soft tissue masses on unenhanced CT scans. Two mediastinal tumors demonstrated the irregular, heterogeneous soft tissue masses. Calcifications were found in 2 tumors. The tumors demonstrated heterogeneously enhancement in 16 cases and homogeneous enhancement in 1 case on contrast-enhanced scans. FDG-PET/CT images revealed increased metabolic activity in all 6 cases undergone FDG-PET/CT scan, and the lesion SUVmax ranged from 4.0 to 18.6. At initial diagnosis, CT and FDG-PET/CT scans revealed rib destruction in 9 cases, pleural effusion in 9 cases, and lung metastasis in 1 case. At follow-up, 12 cases showed recurrence and/or metastases, 4 cases showed improvement or remained stable, and 1 was lost to follow-up.In summary, CT and FDG-PET/CT images of Askin tumors showed heterogeneous soft tissue masses in the chest wall and the mediastinum, accompanied by rib destruction, pleural effusion, and increased FDG uptake. CT and FDG-PET/CT imaging play important roles in the diagnosis and follow-up of patients with Askin tumors.

A rare mediastinal tumour in a young male mimicking massive pleural effusion

A 30-year-old male, carpenter by profession, presented with a history of dry cough and progressive shortness of breath for two months along with right-sided chest pain for one and a half months. The clinico-radiological picture was suggestive of right-sided massive pleural effusion. Computed tomography (CT) scan of the thorax showed a huge mediastinal mass occupying the entire right hemithorax with very small amount of pleural effusion. CT-guided fine needle aspiration cytology and tru-cut biopsy from the mass both revealed small round-cell tumour, possibly small cell carcinoma of the lung. However, on immunohistochemistry tumour cells expressed Mic-2 and it was consistent with a diagnosis of primitive neuroectodermal tumour.

Extraskeletal Ewing's sarcoma presenting as a posterior mediastinal mass

The Ewing's sarcoma family of tumors is an uncommon group of malignant neoplasms that may be located in both skeletal and extraskeletal regions. Extraskeletal Ewing's sarcoma (EES) is quite rare and predominantly involves the soft tissues of the trunk or the extremities. Herein, we report the case of a 19-year-old female patient who complained of left arm pain. Simple chest radiography revealed an opacity occupying almost the entire left hemithorax. Diagnostic imaging techniques demonstrated a solid contrast-enhanced mass in the posterior mediastinum. There was an evident mediastinal shift, and the left lung was collapsed. Even though lymphoma was considered as an initial diagnosis, a biopsy was taken and its histopathological analysis revealed EES. In the literature, there have been only a few case reports of ESS located in the mediastinum. We conclude that, although this is an unusual location, EES should be contemplated in the differential diagnosis of mediastinal masses.