Esophageal extraskeletal neoplasm Ewing's sarcoma: Case report

Introduction and importance: Ewing sarcomas are a group of small round cell tumors that occur predominantly in the long bones as well as in extraosseous locations such as the extremities, trunk, and retroperitoneum (Gier, 1997) [2]. Extraosseous Ewing sarcoma (EES) is a type of small round cell tumor that occurs in soft tissues. I rare cases, EES occurs in the esophagus (Maesawa et al., 2002; Johnson et al., 2010) [1,3]. Ewing's sarcoma is a rare and highly aggressive cancer most frequently arising in people under 20 years of age. We report an uncommon case of primary paraesophageal Ewing's sarcoma in a 25-year-old female. Case presentation: A 26 years old Asian female referred primarily for surgical treatment due to esophageal cancer detected on her diagnostic investigations and revealed a primary tumor located near the gastroesophageal junction. Based on the results of diagnostic investigations which confirmed the possibility of the tumor Ewing sarcoma of esophagus, which was biopsy and immune histochemical stain proven the patient was qualified for surgical treatment. She underwent Mckewon esophagectomy on October 2021 for Ewing sarcoma of esophagus. She was first followed with neoadjuvant intravenous chemotherapy, after taking three cycles of neoadjuvant chemo showed good response in CT scan the patient underwent Mckewon esophagectomy, post op recovery was smooth she underwent 2 cycles of adjuvant chemotherapy after four months of surgery. Her followup visit was uneventful. Clinical discussion: Ewing's sarcoma is the second most frequent primary malignant bone cancer, after osteo-sarcoma. It was first described by James Ewing in 1921, as an undifferentiated tumor developing in the diaphysis of the ulna of a young female patient (Ushigome et al., 2002) [6]. Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET), previously thought to be separate tumors, is now treated as the same tumor; both have similar immunohistochemical characteristics and chromosomal translocation (Maesawa et al., 2002) [1]. They are malignant tumors composed of undifferentiated small round cells, usually affecting children, adolescents, and young adults (Kondo et al., 2005) [7]. Generally ES/PNET affects the bones and deep soft tissues (Soulard et al., 2005) [8], although other organs such as the pancreas, small bowel, esophagus, kidneys, prostate, ovaries, vagina and rectovaginal septum have been reported; this is termed as extraskeletal ES/PNET (Bloom et al., 1995) [9]. To the best of our knowledge, only 5 cases of gastric ES/PNET have been reported in the English language literature. Extraskeletal Ewing's sarcoma is a very rare disease, accounting for 6 %-47 % of all cases of Ewing's sarcoma. It is mainly diagnosed in the trunk, extremities, retroperitoneum, and head and neck region. Patients with extra -osseous Ewing's sarcoma are more likely to be older, female, and not of Caucasian origin. An extraskeletal origin of the disease is correlated to poor prognosis (Siegel et al., 1988; Granowetter and West, 1997; Ushigome et al., 2002) [4-6]. We present an uncommon case of extraskeletal Ewing's sarcoma, and discuss its rare presentation and evolution. To our knowledge, this is the first reported case of paraesophageal primary Ewing's sarcoma and primitive neuroectodermal tumor. Adenocarcinoma and squamous cell carcinoma account for the vast majority of esophageal malignancies. Other malignancies known to occur in the esophagus include melanoma, sarcoma, and lymphoma. Among the sar-comas, carcinosarcoma is the commonest with both carcinomatous and sarcomatous elements followed by leiomyosarcoma of mesenchymal origin. Other sarcomas reported in the literature are liposarcoma, synovial sarcoma, myxofibrosarcoma, Ewing's sarcoma, granulocytic sarcoma, histiocytic sarcoma, schwannoma rhab-domyosarcoma, and epithelioid sarcoma. Conclusion: Ewing sarcoma is a rare entity among all esophageal malignancies. It presents as an exophytic mass, and in this case, it has presented as a mass occluding the lumen of esophagus. Most of these tumors present in locally advanced and disseminated condition, one of the reasons being difficulty and hence delay in diagnosis. In spite of best efforts, a group among them remains to be histologically uncharacterized.