PMC7508692_01
Imaging findings on admission. (a) Esophagogastroscopy showed an elevated tumor in the lower thoracic esophagus. (b) A histopathological examination of the biopsy showed poorly differentiated squamous cell carcinoma. (c) Chest computed tomography showed stenosis of the esophageal lumen due to primary tumor. (d) Abdominal computed tomography showed enlarged lymph nodes along the celiac artery.
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Esophagogastroscopy revealed an elevated tumor in the lower thoracic esophagus (Fig. 1a). A histopathological examination of the biopsy showed poorly differentiated squamous cell carcinoma (Fig. 1b). Chest and abdominal computed tomography (CT) revealed stenosis of the esophageal lumen due to tumor (Fig. 1c) and enlarged lymph nodes along the celiac and common hepatic arteries (Fig. 1d), but no distant metastasis was observed.
Macroscopic and microscopic findings of the resected specimen. (a) Surgical specimen of the esophagus. The resected specimen was a multinodular, elevated, and black-pigmented tumor. (b) A histopathological examination using hematoxylin-eosin stain showed that atypical cells with brown pigment were scattered in the tumor. (c) Tumor cells stained positive for human melanoma black 45. (d) Tumor cells stained positive for melan A.
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The resected specimen was a multinodular, elevated, and pigmented tumor measuring 75 x 40 mm (Fig. 2a). A postoperative histopathological examination revealed that atypical cells with irregularly sized nuclei and brown pigment were scattered in the tumor (Fig. 2b). Immunohistochemical staining demonstrated positive expression of human melanoma black 45 (HMB45) (Fig. 2c), melan A (Fig. 2d), and S100.
Computed tomography (CT) and positron emission tomography-computed tomography (PET-CT) findings in the recurrence site. (a) Abdominal CT 16 months after surgery showed a 36-mm mass in the retroperitoneum at the lateral portion of the ascending colon. (b) PET-CT 16 months after surgery showed hypermetabolic lesions in the retroperitoneum with a maximum standardized uptake value of 5.8. (c) Abdominal CT after 2 courses of nivolumab. The maximum diameter of the tumor was 18 mm. (d) Abdominal CT after 4 courses of nivolumab. The maximum diameter of the tumor was 14 mm. (e) Abdominal CT after 6 courses of nivolumab. The maximum diameter of the tumor was 10 mm. (f) PET-CT after 8 courses of nivolumab. Although the 10-mm mass remained, abnormal accumulation of the retroperitoneal mass disappeared.
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In September 2018, 16 months after surgery, the abdominal CT revealed a 36-mm mass in the retroperitoneum at the lateral portion of the ascending colon (Fig. 3a). PET-CT showed hypermetabolic lesions in the retroperitoneum with a maximum standardized uptake value of 5.8 (Fig. 3b). Abdominal CT showed that retroperitoneal metastasis had reduced in size in response to nivolumab treatment with a maximum diameter of 18 mm after 2 courses (Fig. 3c), 14 mm after 4 courses (Fig. 3d), and 10 mm after 6 courses (Fig. 3e). After 8 courses of nivolumab, although a 10-mm mass remained, abnormal accumulation of the retroperitoneal mass disappeared on PET-CT (Fig. 3f).