대한흉부영상의학회 Weekly Chest Cases

Case No : 1202 Date 2020-11-06

Courtesy of Cho Hee Kim, Tae Jung Kim / Samsung Medical Center
Age/Sex 74 / F
Chief ComplaintPostprandial chest pain

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Diagnosis With Brief Discussion

Diagnosis: Esophageal schwannoma
Radiologic Findings: Figure 1. Chest radiograph shows increased opacity at the left paratracheal area associated with right sided tracheal deviation.
Figure 2. Unenhanced chest computed tomography (CT) shows that the mass in the left tracheal area is homogenous, and iso-attenuating with chest wall muscle.
Figure 3-5. Contrast-enhanced chest CT images show an upper esophageal mass of well-defined and homogenous density that adheres to the wall of the esophagus suggestive of a submucosal tumor.
Figure 6. FDG positron emission tomography image shows the mass with avidly increased uptake of FDG.
Brief Review: Gastrointestinal schwannomas are uncommon benign neoplasms that are uniquely different from conventional soft t issue and central nervous system schwannomas. Histologically, gastrointestinal schwannomas are S-100 protein–positive spindle cell tumors with a microtrabecular pattern, peripheral lymphoid cuffing, and occasional germinal centers. They typically do not show a nuclear palisading pattern and lack of neurofibromatosis-2 genetic alterations that is usually present in conventional schwannomas.
Gastrointestinal schwannomas are classified as mesenchymal or neuroectodermal neoplasms, which are hypothesized to arise from the myenteric plexus within the gastrointestinal tract wall.
Gastrointestinal schwannomas occur most commonly in the stomach (60–70%), followed by the colon and rectum; and esoph¬ageal schwannomas are rarely found.
Esophageal schwannomas occur primarily in the middle-aged women and are usually located in the upper esophagus. Esophageal schwannomas are usually asymptomatic; some¬times, they can initially cause dysphagia, and later in the course of disease, dyspnea occurs due to tracheal compression.
The CT findings of gastrointestinal schwannomas is homogeneously attenuating well-defined mu¬ral mass. A differential diagnosis for a mass arising in the wall of the gastrointestinal tract is a GIST because it is the most common mesenchymal neoplasm of the gastrointestinal tract. But the most difference in the CT features of GISTs compared with schwannomas is the presence of hemorrhage, necrosis, and cystic change, which give GISTs a much more heterogeneous appearance on CT. Esophageal schwannomas, which presented with the characteristic of homogeneously attenuating well-defined mural mass, is indistinguishable from leiomyoma on the basis of imaging alone.
The FDG uptake of schwannomas can be variable. Schwannomas generally have a high tumor-to-background ratio on FDG PET. Beaulieu et al. reported 50% (5/10) of the lesions showed an SUVav greater than 3.0. An SUVmax of 6.0 cannot exclude schwannoma from the differential diagnosis. Distinguishing schwannomas from malignant peripheral nerve sheath tumors before biopsy or surgery is not possible. Schwannoma should be included in the differential diagnosis of peripheral nerve sheath tumors with low, intermediate, or high SUVs.
Most of gastrointestinal schwannomas are biologically benign and that most patients have an excellent prognosis after surgical resection.
References: 1. Levy AD, Quiles AM, Miettinen M, Sobin LH. Gastrointestinal schwannomas: CT features with clinicopathologic correlation. AJR Am J Roentgenol. 2005;184(3):797-802.
2. Lee, Man Ho, et al. "CT Findings of Esophageal Schwannoma: A Case Report." Journal of the Korean Society of Radiology 72.3 (2015): 189-192.
3. Beaulieu, Sylvain, et al. "Positron emission tomography of schwannomas: emphasizing its potential in preoperative planning." American Journal of Roentgenology 182.4 (2004): 971-974.
Keywords: esophagus, gastrointestinal, neurogenic tumor, schwannoma ,

No. of Applicants : 63

▶ Correct Answer : 7/63, 11.1%

- Diagnose.me (BV) / Royal Perth Hospital , Australia YURANGA WEERAKKODY
- Asan Medical Center , Korea (South) EUNJI CHOI
- Kinki University Faculty of Medicine, , Japan MITSURU MATSUKI
- The University of Tokyo Hospital , Japan MOTO NAKAYA
- Other , Korea (South) MINSU KIM
- Chonbuk National University Hospital , Korea (South) KUM JU CHAE
- , Japan SOTA MASUOKA

▶ Correct Answer as Differential Diagnosis : 17/63, 27.0%

- Narayana Multispeciality Hospital Jaipur Rajasthan , India JAINENDRA JAIN
- Saitama-Sekishinkai Hosptal , Japan MIHOKO YAMAZAKI
- University of Tsukuba, Dept of Radiology , Japan MANABU MINAMI
- , Japan HIROAKI ARAKAWA
- Other , Korea (South) KYU-CHONG LEE
- McGill , Canada ADRIANA SOFIA MORALES
- Osaka City General Hospital , Japan SHU MATSUSHITA
- Ichinomiya Nishi Hospital , Japan Takao Kiguchi
- Korea University Guro Hospital , Korea (South) LEE SEOKYOUNG
- Toranomon Hospital , Japan KAORU SUMIDA
- Eskisehir Sehir Hastanesi , Turkey MURAT SAHIN
- , Japan HIROAKI ARAKAWA
- Private sector , Greece VASILIOS TZILAS
- Gifu University Hospital , Japan Yo Kaneko
- National Center for Global Health and Medicine , Japan MASATOSHI HOTTA
- Hamamatsu University Hospital , Japan HAYATO NOZAWA
- Chungbuk National University Hospital , Korea (South) YEONGTAE PARK

▶ Semi-Correct Answer : 3/63, 4.8%

- Chonnam National University Hospital , Korea (South) SEUNGYOON CHAE
- Showa University Fujigaoka Hospital , Japan KYOKO NAGAI
- Chungbuk National University Hospital , Korea (South) MIHYEON PARK

대한흉부영상의학회 Korean Society of Thoracic Radiology

Archive of Old Cases

Case No : 1202 Date 2020-11-06

Discussion

No. of Applicants : 63