Diagnostic role of 18F-fluorodeoxyglucose positron emission tomography for follicular lymphoma with gastrointestinal involvement

Figure 1 Typical histological features of follicular lymphoma. A, B: Small cleaved cells that infiltrated the duodenal mucosa and formed lymphoid follicles are present (hematoxylin and eosin staining); C: Representative immunohistochemical staining of lymphoma cells negative for CD3; D: Lymphoma cells positive for CD10; E: Lymphoma cells positive for BCL-2. All of the images shown are at 40 × magnification, except for panel B which is at 400 × magnification.

Figure 2 Endoscopic images of follicular lymphoma. A: A gastric lesion with thickened rugae exhibiting a slight redness; B: Typical features of the whitish polypoid granules observed in the duodenum; C: Whitish polypoid lesions in the jejunum; D: Indigo carmine contrast was used to emphasize the slightly elevated small polyps present in the colon; E: An elevated lesion with a flat surface and a 20 mm diameter was observed in the rectum; F: In another patient, polypoid lesions exhibiting hypervascularity on the surface were detected in the rectum.

Figure 3 A 60-year-old male patient with duodenal follicular lymphoma without nodal lesions (Lugano system stage I, grade 1). A: An esophagogastroduodenoscopy detected features typical of primary duodenal follicular lymphoma, including small whitish nodules; B, C: 18F-fluorodeoxyglucose positron emission tomography detected tracer uptake in the duodenal second portion (indicated with arrows).

Figure 4 A 65-year-old female patient with duodenal and jejunal follicular lymphoma and intra-abdominal lymph node involvement (Lugano system stage II-1, grade 1). A: An esophagogastroduodenoscopy revealed small whitish nodules present in the duodenum; B: Video capsule endoscopy also identified small nodules present in the jejunum; C, D: 18F-fluorodeoxyglucose positron emission tomography detected tracer uptake in the duodenum (C) and the jejunum (D).

Figure 5 A 37-year-old female patient with systemic follicular lymphoma and extended gastrointestinal involvement from the duodenum to the rectum (stage IV, grade 1). A: An esophagogastroduodenoscopy detected small whitish nodules present in the duodenum; B, C: A colonoscopy revealed multiple polyps present in the ileum (B), cecum, colon (C), and rectum. Jejunal involvement was confirmed by video capsule endoscopy; D: During 18F-fluorodeoxyglucose positron emission tomography, tracer uptake was only noted in the ileum and colon.

Figure 6 A 61-year-old female patient with follicular lymphoma and duodenal involvement (Lugano system stage IV, grade 1). A: In the duodenum, small whitish nodules were observed; B: 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) detected tracer uptake in the duodenum (indicated with an arrow); C: 18F-FDG-PET identified diffuse lymphoma infiltration into the spleen (indicated with an arrow), which was not detected by computed tomography scanning. In this case, these results upgraded the clinical stage.