PMC4090213_01
Histological sections from the pseudocyst (A-F), pancreas body (G-O), and pancreas head (R). Sections in A, D, G, J, M, and R were stained by hematoxylin and eosin; in B, E, H, K, and N, by IgG4 immunohistochemistry; and in C, F, I, L, and O, by CD138 immunohistochemistry. The top 5 rows (ie, A-C, D-F, G-I, J-L, and M-O) were from an individual tissue sample. Also shown are the positive controls of IgG4 staining on a human tonsil specimen (P) and the negative control of CD138 staining without the primary antibody (Q). Scale bars indicate 100 mum in A-C, G-I, Q, and R; 50 mum in P; 20 mum in D-F and J-L; and 10 mum in M-O.
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F1
The cyst wall had severe fibrosis, with mild inflammation adjacent to the adipose tissue (Fig. 1A). Coexpression of CD138, which was used for the marker of plasma cells, and IgG4 was observed in the cyst wall (Fig. 1B-C). A dense lymphocyte infiltration was also seen in the wall (Fig. 1D), and several IgG4-positive plasma cells were present (Fig. 1E-F). The pancreas body showed moderate to severe fibrosis (Fig. 1G) and CD138 expression (Fig. 1I), but no IgG4 stain (Fig. 1H). CD138 expression was seen in the islet area (Fig. 1K-L). CD138-positive plasma cells (Fig. 1M and O) were present in the pancreas parenchyma but were not stained by IgG4 immunostaining (Fig. 1N). The section from the pancreas head also showed severe fibrosis with mild inflammation (Fig. 1R).