Figure 2
End-stage lymphoma-bearing mouse images show specific accumulation of 67Ga-citrate in parathymic lymph nodes. (a) MRI: enlarged mediastinal lymph node conglomerate with signs of tumor infiltration (red arrowhead). (b) 67Ga-citrate SPECT/MRI: SPECT/MRI assessment shows tracer accumulation in a part of the left parathymic lymph node (from left to right in this panel, sagittal, horizontal and axial plane view, focused on the parathymic region). The red full arrowhead shows the tracer accumulating part of the infiltrated lymph node, while the empty arrowhead points to the part of the enlarged lymph node not accumulating 67Ga-citrate. (c) Ex-vivo Cerenkov image shows 67Ga-citrate accumulation in the previously identified part of the parathymic lymph node and low accumulation in the part identified with the empty arrowhead in SPECT/MRI. Scale bar corresponds to 1 cm. (d) Stereomicroscopic image of the same parathymic lymph node. Two areas are identified, * in the lower rectangle shows the tumor-infiltrated part, its histology analysis image indicated by a purple arrow, ** in the upper rectangle identifies the tumor infiltration border area in the lymph node. The corresponding immunohistochemistry image in (f) is pointed at with a red arrow. (e) Haematoxylin–eosin staining microscopy image of a section from the infiltrated part of the parathymic lymph node, identified with (a) * in (d). The sample is taken from the area in the lower rectangle of the stereomicroscopic image shown with *. Small clusters of residual normal lymphocytes (arrow) are visible, surrounded by large lymphoma infiltrates composed of irregularly shaped lymphoblasts (arrowhead). (f) Immunofluorescence histological image from the transitional area of the lymph node labeled **, delineated in the upper rectangle of the stereomicroscopic image in (e) demonstrates the remnant of original follicle composed of IgM/B220 double positive B cells adjacent to B220 single positive DLBCL cells (green: IgM, red: B220). Scale bar = 100 µm.
