Fig. 2

Anatomy and histology of OM. a Representation of the anatomical location of all OM. Red dots represent metastases from an IDC primary, blue dots represent metastases from an ILC primary, mixed red and blue dots represent metastases from a mixed IDC/ILC primary, and green dots represent metastases from a primary of unknown histological subtype. Numbers indicate how many patients were affected by OM to this location. In cases where patients had OM to multiple locations within the ophthalmic region, each location was displayed separately. Graphic courtesy of Shutterstock [23]. b Histologic analysis of the primary breast tumor for case 24 shows a mixed pattern of invasive lobular and ductal carcinoma. The majority of the tumor is composed of lobular carcinoma, showing single infiltrating cells and linear cords of cells dissecting stroma, which are negative for E-cadherin staining but positive for ER (top row). A discrete, although minor component of the tumor is composed of somewhat larger infiltrating cells forming clusters; these clusters are strongly E-cadherin positive and ER positive (middle row). The biopsy of metastatic disease in the left lower eyelid shows only lobular pattern metastatic carcinoma that is E-cadherin negative and ER positive (bottom row). c Two other cases of periorbital metastatic breast cancer in unrelated patients are shown. For these cases, the primary breast cancer specimens were not available for review. In both cases, the histologic features of metastatic carcinoma show some lobular pattern infiltration, particularly for case 1, but features that are more in keeping with metastatic ductal carcinoma. E-cadherin staining is strongly and diffusely positive for both cases, and both are ER positive. Scale bar = 100 μm