Multinucleated giant cells of bladder mucosa are modified telocytes: Diagnostic and immunohistochemistry algorithm and relation to PD-L1 expression score

Figure 5 Immunohistochemical examination of urothelial carcinoma of the bladder. A: Presence of several pericapillary multinucleated giant cells (MGCs) in the mucosa, which were CD31-negative (arrow); the endothelial cells of the surrounding capillaries served for internal positive control. immunohistochemical (IHC), CD31 × 400; B: Presence of several pericapillary MGCs in the mucosa, which were CD10-negative (arrow). IHC, CD10 × 400; C: The presence of two pericapillary MGCs in the bladder’s mucosa, which were found negative for C-KIT (arrow); positively labeled pericapillary mast cells were used for internal positive control. IHC, C-KIT × 630; D: MGCs in the bladder mucosa were always accompanied by many pericapillary C-KIT positive mast cells. IHC, C-KIT × 630; E: Giant cells were p16-positive (arrow). IHC, p16 × 400; F: Presence of two pericapillary MGCs in the mucosa that are negative immunoglobulin G4 (IG G4) for IG G4; several positively labeled pericapillary plasma cells were used for internal positive control. IHC, IG G4 × 630.