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| CASE REPORT |
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| Year : 2023 | Volume
: 43
| Issue : 6 | Page : 285-287 |
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Esophageal schwannoma with unusual endoscopic ultrasound imaging findings
Fu-Chieh Hsu1, Tsai-Wang Huang2
1 Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
2 Division of Thoracic Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| Date of Submission | 28-Oct-2022 |
| Date of Decision | 26-Feb-2023 |
| Date of Acceptance | 09-Mar-2023 |
| Date of Web Publication | 26-May-2023 |
Correspondence Address:
Dr. Tsai-Wang Huang
Division of Thoracic Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Chenggong Rd., Neihu Dist., Taipei 114
Taiwan
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/jmedsci.jmedsci_238_22
Esophageal schwannomas are a subset of rare tumors that are difficult to differentiate from other esophageal tumors preoperatively. On endoscopic ultrasound (EUS), esophageal schwannomas generally appear as well-demarcated masses that are heterogeneous, hypoechoic, or mixed-echogenic in nature. We present a case of esophageal schwannoma with atypical EUS findings. EUS revealed two lobulated tumors that originated from the muscularis propria and characterized by heterogeneous hypoechoic features and poor blood flow signals. Right-sided video-assisted thoracoscopic surgery with esophageal tumor enucleation was performed. Immunostaining finally confirmed the diagnosis of an esophageal schwannoma. Esophageal schwannomas tend to show heterogeneous hypoechoic or mixed-echogenic features, but they rarely present with two lobulated masses.
Keywords: Esophageal tumors, esophageal schwannoma, endoscopic ultrasound, video-assisted thoracoscopic surgery
How to cite this article:
Hsu FC, Huang TW. Esophageal schwannoma with unusual endoscopic ultrasound imaging findings. J Med Sci 2023;43:285-7 |
| Introduction | |  |
Leiomyomas account for the majority of benign esophageal tumors.[1] Of them, the esophageal schwannomas are rare[2] and therefore challenging to differentiate from other tumors, such as leiomyosarcomas, leiomyomas, and mediastinal tumors.[3] Here, we describe the case of an 82-year-old woman who presented with a bulging subepithelial lesion located proximal to the esophagogastric junction, which was detected on esophagoscopy. Endoscopic ultrasound (EUS) revealed an atypical image of the esophageal tumor, which was eventually diagnosed as an esophageal schwannoma after surgical enucleation. The tumor presented as two lobulated masses from the muscularis propria with heterogeneous hypoechogenicity.
| Case Report | | |
An 82-year-old female presented with dysphagia and poor appetite for approximately 1 month. The patient denied any comorbidity, and there were no significant findings in her medical history or family history. Laboratory investigation only revealed a high cholesterol level and normal tumor marker levels, including carcinoembryonic antigen and squamous cell carcinoma antigen levels. Upper gastrointestinal (GI) endoscopy revealed a bulging subepithelial lesion located 40 cm from the incisors and proximal to the esophagogastric junction [Figure 1]. EUS (Olympus GF-UE260) revealed two lobulated tumors derived from the muscularis propria with heterogeneous hypoechoic features and poor blood flow signals [Figure 2]. Contrast-enhanced computed tomography (CT) of the chest revealed a mildly lobulated homogeneous soft tissue mass with a circumscribed margin located over the posterolateral aspect of the lower-third part of the esophagus [Figure 3]. Physical examination, whole-abdominal sonography, and other examination modalities revealed no abnormal findings. | Figure 1: Upper gastrointestinal endoscopy revealing a bulging subepithelial lesion located 40 cm from the incisors and proximal to the esophagogastric junction
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 | Figure 2: Endoscopic ultrasound revealing two lobulated tumors (green and blue arrows) derived from the muscularis propria showing heterogeneous hypoechoic features and poor blood flow signals
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 | Figure 3: Contrast-enhanced computed tomography of the chest depicting a mildly lobulated homogeneous soft-tissue mass (blue arrow) with a circumscribed margin located over the posterolateral aspect of the lower third of the esophagus
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Right-sided video-assisted thoracoscopic surgery with esophageal tumor enucleation was performed. The tumor over the lower third of the esophagus adhered to the aorta and mediastinum, and it was barely possible to dissect it from the esophageal muscular layer. A 5.5 cm × 3.5 cm × 3.5 cm well-encapsulated tumor with a yellowish cut surface and a hard elastic texture was successfully resected [Figure 4]a and [Figure 4]b. Two different components were used for frozen sectioning. | Figure 4: (a and b) A 5.5 cm × 3.5 cm × 3.5 cm well-encapsulated tumor (blue and red arrows) with a yellowish cut surface and hard elastic texture was resected
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Microscopic examination revealed proliferative spindle cells arranged in a whorled pattern and focal lymphoid tissues [Figure 5]. Histopathological examination revealed a tumor arising from the esophageal muscular layer and the formation of peripheral lymphoid follicle. An esophageal schwannoma was diagnosed based on the appearance of tumor cells, which were positive on immunostaining for S-100 and Ki-67 and negative for CD117, DOG-1, and desmin. The postoperative course was uneventful, and the contrast CT of the chest 3 months later showed only the retained surgical clips over the lower third of the esophagus. There has been no evidence of recurrence to date. | Figure 5: Microscopic examination results revealed proliferative spindle cells arranged in a whorled pattern and focal lymphoid tissues
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| Discussion | | |
Approximately 2% of all esophageal tumors are benign, and most of them are leiomyomas.[2] Esophageal schwannomas are extremely rare and predominantly develop in women in their 50s. As most patients are asymptomatic, the tumors are diagnosed incidentally.[4] Dysphagia is the most common presenting symptom, but dyspnea, chest pain, epigastric pain, and hemoptysis may also occur.[1],[4] GI schwannomas originate from Schwann cells of the axon of Auerbach's plexus or, less frequently, of Meissner's plexus. These tumors can span the entire thoracic esophagus but usually occur in the upper thoracic segment.[4],[5] The present patient had a tumor in the lower third of the esophagus. Because accurate diagnosis during routine endoscopy was challenging, EUS was performed. All submucosal lesions >1 cm in size are assessed by EUS.[6] EUS can distinguish the specific layer of the GI tract wall, determine the layer from which the lesion is derived, and even acquire cells or tissues for histopathology using EUS fine-needle aspiration biopsy. Su et al.[7] reported that GI schwannomas generally present as heterogeneous hypoechoic or mixed-echogenic masses originating from the muscularis propria with clear boundaries and poor blood flow signals. In addition, EUS real-time tissue elastography can help distinguish between benign and malignant tumors as the hardness of tissues are evaluated using a 5-point scoring system.[8] However, biopsies should be avoided in probable esophageal leiomyomas or GI stromal tumors (GISTs) because postbiopsy scarring may hinder surgical enucleation.[9] As a result, establishing a preoperative definitive tissue diagnosis is challenging. On CT scans, esophageal schwannomas display a homogeneous denseness, while leiomyomas often show calcification. In contrast, leiomyosarcomas, being malignant, are more heterogeneous. Urgent surgical resection is recommended for the removal of symptomatic lesions, lesions that have increased in size during follow-up, or premalignant lesions (GIST size >2 cm).[1],[10] Video-assisted thoracic surgery for enucleation is preferable because of the shorter length of hospital stay, less postoperative pain, and fewer postoperative complications.
| Conclusion | | |
Esophageal schwannomas show a homogeneous density, whereas leiomyomas often show calcification on CT scans. Esophageal schwannomas show heterogeneous hypoechoic or mixed-echogenic features, and originate from the muscularis propria. They rarely present with two lobulated masses as seen in the present case.
Ethical approval
The study has been approved by an ethics committee: (TSGHIRB No: A202215169).
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed.
Data availability statement
The data that support the findings of this study are available from the corresponding author, Huang TW, upon reasonable request.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
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| 6. | Eckardt AJ, Jenssen C. Current endoscopic ultrasound-guided approach to incidental subepithelial lesions: Optimal or optional? Ann Gastroenterol 2015;28:160-72. |
| 7. | Su Q, Peng J, Chen X, Xiao Z, Liu R, Wang F. Role of endoscopic ultrasonography for differential diagnosis of upper gastrointestinal submucosal lesions. BMC Gastroenterol 2021;21:365. |
| 8. | Lv H, Zhu G, Zhou L. Diagnostic value of endoscopic ultrasound elastography for benign and malignant digestive system tumors. Pak J Med Sci 2019;35:1461-5. |
| 9. | Lee HJ, Park SI, Kim DK, Kim YH. Surgical resection of esophageal gastrointestinal stromal tumors. Ann Thorac Surg 2009;87:1569-71. |
| 10. | Faigel DO, Abulhawa S. Gastrointestinal stromal tumors: The role of the gastroenterologist in diagnosis and risk stratification. J Clin Gastroenterol 2012;46:629-36. |
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
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