The 21-year-old female patient was admitted to the thoracic surgery department of our hospital due to progressive dysphagia accompanied by nausea and vomiting after meal consumption for 2 months. Chest computed tomography (CT) showed a spherical soft tissue mass in the upper thoracic esophagus, with obvious narrowing of the lumen (Fig. 1). The size of the lesion was about 30 x 26 mm, which was mild uniform enhancement. No obvious enlarged lymph nodes were found in the mediastinum. Abdominal CT, neck ultrasound, brain MRI, and bone ECT revealed no obvious abnormalities. Flexible esophagoscopy confirmed a large polypoid mass 18 cm away from the incisor teeth, completely obstructing the esophagus within the intact mucosal surface, presenting with formation of mucosal bridges (Fig. 2a). Endoscopic ultrasonography of esophagus showed that the lesion arose from the esophageal muscularis propria with a smooth and continuous adventitia (Fig. 2b). The primary clinical diagnosis was that of submucosal lesions of the upper thoracic esophagus, possibly a leiomyoma.
Thoracoscopic esophageal lesion resection under general intravenous anesthesia after completing all investigation was done. A 2.9 x 2.1 x 3.0 cm mass in the upper thoracic esophagus was seen during the operation. Taking precautions to avoid any damage, the muscle layer was carefully separated, and the mucosa was carefully peeled off. After complete tumor removal, the muscle layer defect was about 3 cm long, and the mucosal layer was damaged in three spots due to dense adhesions. The mucosal layer was repaired thoracoscopically, and the stumping muscle layer was pulled to the middle for an end-to-end anastomotic procedure, which was covered and sutured using the surrounding pleura.
The resected esophageal mass was submitted to undergo histology, immunochemistry, and genetic studies. Histologically, the tumor consisted of a markedly cellular tissue with a trabecular growth pattern accompanied by hemorrhage on hematoxylin and eosin staining (Fig. 3a). In addition, the classical Homer-Wright rosettes were also seen (Fig. 3b). Tumor cells had small, uniform, mildly atypical nuclei with granular chromatin and small amounts of cytoplasm (Fig. 3a, b).
Immunoperoxidase stains were performed on a Ventana NEXES Automated Immunohistochemistry System (Fuzhou Maixin Biotech Co., Ltd., Fuzhou, China). CD99 (clone O13; Maixin) (Fig. 3c) and P63 (clone MX 013; Maixin) were positive in the tumor cells. Vimentin (clone MX 034; Maixin) was less positive. Furthermore, tumor cells did not stain for synaptophysin (clone SP 11; Maixin), pan-cytokeratin (clone AE1/AE3; Maixin), and CD56 (clone 123C3. D5; Maixin) (Fig. 3d). Ki-67 was reactive in approximately 55% of the tumor cells. Formalin-fixed and paraffin-embedded tissue sections were prepared, and fluorescence in situ hybridization (FISH) was performed with the EWSR1/FLI1 Fusion Translocation t(11;22) Probe (Guangzhou LBP Medicine Science & Technology Co., Ltd., Guangzhou, China), and two hundred interphase cells were examined. The patient's sample was positive for EWS/FLI1 transcripts associated with t(11;22)(q24;q12) (Fig. 3e), which signal modes are as follows: 1 G1R1F 37.0%, 2 G1R1F 10.0%, 2 G2R1F 4.0%, 1 G1F 10.0%, 2 G1F 10.0%, 1R1F 7.5%, 1R2F 5.0%, 1 G2F 7.5%, and 1 G1R2F 9.0%.
After 2 months after the operation, the patient received 2 cycles of EP (etoposide/cisplatin) chemotherapy, followed by chest radiotherapy and concurrent EP regimen chemotherapy for 2 cycles and then continued to receive 2 cycles of EP regimen adjuvant chemotherapy. Chest radiation was delivered using intensity-modulated radiation therapy (Fig. 4a-c) as follows: the planning gross tumor volume of the tumor bed (TB) (PGTVtb) and planning target volume (PTV) were administered using 56 and 50.4 Gy in 28 daily fractions of 1.8-2.0 Gy, respectively. The clinical target volume (CTV) depended on the location of the primary tumor and was irradiated using involved-field radiotherapy. The CTV included GTVtb with a radial margin of 0.5-1.0 cm and a longitudinal margin of 3 cm. The CTV and GTVtb with a margin of 0.5 cm in three dimensions formed the PTV and PGTVtb, respectively. Chemotherapy consisted of cisplatin 25 mg/m2 and etoposide 100 mg/m2 per day on days 1 through 3 every 21 days for up to six cycles.
The patient has been followed up regularly for one and half years after surgery and for 1 year after adjuvant radiotherapy/chemotherapy including clinical examination, ECT, chest CT, and gastroscopy. No obvious signs of recurrence or metastasis were found, and the patient's general condition was satisfactory.