Decidualized Ovarian Mass Mimicking Malignancy

Figure 2

Microscopic examination of the left decidualized ovarian mass. Low magnification (a) shows an exophytic lesion developed on ovary surface (hematin eosin, ×0.5). High magnification (b) shows bland eosinophilic and granular epithelioid cells with no atypia nor mitotic activity (hematin eosin, ×20). By immunohistochemistry with calretinin (c) the epithelioid cells are negative (positive mesothelial cells are seen at the top), whereas they are stained by anti-progesterone receptor antibody (d) (brown nuclear positivity).

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