Figure 1.

Peripancreatic lymph node localization of breast carcinoma. A) In this picture pancreatic tissue is observed in the upper-left corner. In the central portion the metastatic lymph node is observed. Lymph node measured 4×2 mm in section and presented heavily metastatic involvement. The area indicated by the white square is magnified in B and C. The area indicated by the black square is shown in D and E at higher magnification (hematoxylin and eosin, ×25). B) Virtually all neoplastic cells are strongly estrogen receptor positive (ER nuclear specific signal; LSABPx, ×200). C) Many tumor cells show a delicate membrane decoration for HER-2 (LSABPx, ×200). D and E) Neoplastic embolization is present, highlighted by staining for CK7 and 19 (data not shown). Note the strong nuclear positivity for ER (D) and the apparently stronger membrane signal for HER-2 (E), in these embolisms. Immunohistochemical characterization was made using a labeled streptavidin biotin peroxidase method (LSABPx). Visualization of the reaction was performed with the Dako LSAB 2 Kit peroxidase, containing labeled streptavidin biotin for primary rabbit/mouse antibody and diaminobenzidine (DAB).