Metastatic colloid carcinoma versus primary carcinoma of the ciliary epithelium

Ocular metastases developed from breast carcinomas in two women 7 and 19 years after their mastectomies. They were both ciliary body metastases that had eroded through the root of the iris to present as unifocal globular, gelatinous (colloid) masses in the anterior chamber, and were amenable to local surgery. Histopathologically, small cellular clusters were widely separated in a sea of mucin; the tumor cells failed to display marked pleomorphism or mitotic activity. In each case, the distinction from a primary mucinous ciliary epithelial neoplasm had to be made both clinically and pathologically. For comparison, the authors also report a unique primary ciliary carcinoma that caused intractable glaucoma by spreading diffusely throughout the iris, ciliary body, and anterior chamber angle, and that necessitated enucleation. The tumor cells failed to produce hyaluronic acid but elaborated a mucosubstance which was histochemically indistinguishable from that of the metastatic carcinomas. This primary neoplasm, however, exhibited the following histologic differences from the metastases: more architectural variability, including garlands and festoons of cells not forming lumens that were suspended in a mucinous matrix; much more abundant intracellular mucin; foci of sheet-like and pleomorphic cellular proliferations with mitotic activity; and partial replacement of the ciliary processes by a comparatively benign-appearing mucinous columnar epithelium.