Mucinous ovarian tumors with giant cell mural nodules. A report of two cases.

Two cases are reported in young women of a variant of ovarian mucinous tumor with giant cell mural nodules. The first tumor was a predominantly proliferating mucinous tumor with a giant cell mural nodule adjacent to foci of haemorrhage and reactive vascular proliferation. No invasive carcinoma could be identified. In the second tumor, which was examined by electron microscopy, a sharp demarcation was observed between typical invasive mucinous carcinoma and areas which, on low-power examination, were indistinguishable from malignant giant cell tumor of soft parts. Closer examination revealed, in these latter areas, an intimate mixture of anaplastic, predominantly mononuclear tumor cells and multinucleate osteoclast-like giant cells. The histogenesis of these lesions is suggested as being reactive to the tumor cells or their products and is discussed with reference to similar tumors reported from the ovary and other sites in the body.