Multiple Ewing Sarcoma/Primitive Neuroectodermal Tumors in the Mediastinum

Abstract

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.

Case report: Primary mediastinal Ewing’s sarcoma presenting with chest tightness

“…Malignant thymoma should be considered first when a large, irregular and uneven mass appears in the anterior mediastinum, which was the reason for misdiagnosis in the study. Malignant thymomas show similar radiologic findings as EWS ( 7 ). However, malignant thymomas are much less malignant than mediastinal ES, such as they usually have no lymph node metastasis and no pleural effusion.…”

Primary Ewing’s Sarcoma of the Penis: First Reported Case in the United Kingdom

“…Extraskeletal occurrence of ES is rare; however, it can occur in any location [ 8 ]. Upon review of the medical literature, we identified cases reported in female and male genital organs such as the vulva, vagina, uterus, ovaries, and testicles [ 9 , 10 ].…”

Mediastinal sarcomas: experience using fine needle aspiration cytopathology

“…The most common among these is the Ewing sarcoma/family of tumors (ES). As a mediastinal primary, ES is exceptionally rare in contrast to its more common thoracopulmonary location ( 63 , 64 ). Aspiration cytopathology consists of highly cellular smears with monotonous cells about 2–3 times the diameter of a mature lymphocyte dispersed individually with a minority in loose clusters.…”