Serous carcinoma of the ovary with squamous differentiation: a case report and a literature review.

Serous carcinoma of the ovary showing squamous differentiation is a rarely reported neoplasm. We present 1 case of such a tumor extensively involving the adnexa and the pelvis, which shows these 2 intimately entwined, yet with morphologically and immunohistochemically distinct patterns of differentiation. We also report immunohistochemical evidence of protein expression changes in areas of this carcinoma that provide evidence for differentiation from a serous to a squamous phenotype.