PMC4766227_01
Endoscopic appearance of multiple elevated lesions in the lower body of the stomach a before cessation of MTX; b 2 weeks, c 1 month, d 2 months, and e 5 months after cessation of MTX; and f 1 year after chemotherapy. Regression of the elevated lesion is demonstrated
12328_2015_624_Fig1_HTML.jpg
PMC4766227_01_12328_2015_624_Fig1_HTML.jpg
Fig1
An upper endoscopy that had been performed at another clinic revealed multiple round elevated lesions in the middle body of the stomach, similar to submucosal tumors (Fig. 1a). MTX, which clearly demonstrated gradual regression of the elevated lesions (Fig. 1b-e), and atypical lymphoid cell proliferation was absent in each biopsy specimen. Moreover, the follow-up PET-CT 6 months after cessation showed no increased FDG avidity in the stomach (Fig. 3b). Endoscopic examination 1 year after chemotherapy showed completely healed white scars in the lower body of the stomach (Fig. 1f), and no disease recurrence was found.
a Histopathological features of the ulcerative lesion in the stomach, with proliferation of large-sized lymphoid cells. H&E, x400. b Immunohistological findings of the ulcerative lesion, showing that L-26 was expressed in the large lymphoid cells (x400), and c CD3 was not expressed x400. d Few EBER-positive cells were detected by in situ hybridization x400
12328_2015_624_Fig2_HTML.jpg
PMC4766227_01_12328_2015_624_Fig2_HTML.jpg
Fig2
In situ hybridization for EBV (EBER) demonstrated no positivity in the majority of atypical lymphoid cells (Fig. 2a-d).
a-c Coronal PET-CT scan image of the stomach. d-f Axial PET-CT scan image of the mediastinum and chest wall. a Before cessation of MTX, increased FDG avidity was shown in the stomach wall. b Six months after cessation of MTX, no FDG avidity was seen in the stomach wall. c One year after chemotherapy, no FDG avidity was shown in the stomach wall. d Before cessation of MTX, slightly increased FDG avidity was visible in the mediastinum and left chest wall. e Six months after cessation of MTX, the slightly increased FDG avidity in the mediastinum and left chest wall remained unchanged. f One year after chemotherapy. Slightly increased FDG avidity in the mediastinum and left chest wall remained unchanged.
12328_2015_624_Fig3_HTML.jpg
PMC4766227_01_12328_2015_624_Fig3_HTML.jpg
Fig3
Combined positron-emission tomography and computed tomography (PET-CT) using 18F-fluorodeoxyglucose (FDG) showed increased FDG avidity in the stomach (Fig. 3a) in addition to slightly increased avidity in the mediastinum and left chest wall (Fig. 3d). MTX, which clearly demonstrated gradual regression of the elevated lesions (Fig. 1b-e), and atypical lymphoid cell proliferation was absent in each biopsy specimen. Moreover, the follow-up PET-CT 6 months after cessation showed no increased FDG avidity in the stomach (Fig. 3b). While disease regression was observed in the stomach, the FDG-avid spots in the mediastinum and left chest wall remained unchanged (Fig. 3e). On the PET-CT after chemotherapy, the stomach continued to show no FDG avidity (Fig. 3c), while the mediastinum and left chest wall remained unchanged, maintaining slightly increased FDG avidity (Fig. 3f) over follow-up of more than 1 year.