case_images: PMC10761607_01
case_images: Imaging studies of the chest with the relevant timeline. (a-c) Chest contrast-enhanced computed tomography (CT) scan revealed a tumor lesion that was fused between the left hilum and mediastinum (white arrow). The tumor enveloped the left pulmonary artery, and nodules were detected in both lung fields (black arrow). (d) A chest contrast-enhanced CT scan taken eight months after the initiation of treatment showed a reduction in the tumor size around the left pulmonary artery. (e: cross-section, f: coronal-section) A pelvic contrast-enhanced CT scan taken at the same time as that of (d) revealed soft tissue shadows around the abdominal aorta that had increased in size (arrowheads). Soft tissue shadows around the bladder and seminal vesicles had also increased in size. (g: cross-section, h: coronal-section) A positron-emission tomography (PET-CT) scan taken at the same time as that of (d) showed accumulation around the abdominal aorta and bladder. (i: cross-section, j: coronal-section) One month after the initiation of steroid treatment, a CT scan showed a reduction in the soft tissue shadow around the abdominal aorta.
case_images: TCA-15-104-g002.jpg
case_images: PMC10761607_01_TCA-15-104-g002.jpg
case_images: tca15155-fig-0001
case_images: Chest computed tomography (CT) revealed a mass in the left upper lobe, multiple nodules, mediastinal lymph node enlargement, and pleural thickening (Figure 1a-c). Eight months later, the primary lesion size had reduced in size (Figure 1d). The CT scan revealed an increased change in the soft tissue shadow around the abdominal aorta, bladder, and seminal vesicles, suggesting retroperitoneal fibrosis (Figure 1e, f). Positron emission tomography (PET-CT) revealed fluorodeoxyglucose (FDG) accumulation in the same area (Figure 1g,h). One month later, imaging showed a reduction in size of the adipose tissue around the abdominal aorta and bladder (Figure 1i,j).
case_images: Pathological findings of retroperitoneal tissue (a, b: hematoxylin and eosin staining). Microscopic examination revealed lymphocytic infiltration with layered fibrosis (a: 40x, b: 400x) (c: immunohistochemistry [IHC] for IgG). IHC staining demonstrated the presence of IgG-positive plasma cells (x100) (d: IHC for IgG4). IHC staining revealed the presence of numerous IgG4-positive plasma cells. The number of IgG4-positive cells corresponded to approximately 70% of the total number of IgG-positive cells in the same area (100x) (e: IHC for CD3, f: IHC for CD20). Immunohistochemistry demonstrated that lymphocytes were positive for both CD3 (e: x100) and CD20 (f: x100), suggesting an association with both T and B cell lymphocytes (g: IHC for CD4, h: IHC for CD8). T cell lymphocytes infiltrating the lesion were positive for both CD4 and CD8 with a predominance of CD8.
case_images: TCA-15-104-g001.jpg
case_images: PMC10761607_01_TCA-15-104-g001.jpg
case_images: tca15155-fig-0002
case_images: The infiltrating lymphocytes were mainly CD20- and CD79a-positive B cells, and both CD4- and CD8-positive T cells were observed, with CD8 being predominantly present, but no malignancy was observed (Figure 2).