Benign adenoma of the ciliary epithelium with tumour seeding

Congenital adenoma of the iris and ciliary body: light and electron microscopic observations

A 23-year-old man had a lesion in the right inferior iris which appeared to have enlarged since it was first seen when the patient was aged 5 years. The lesion was excised by a partial iridocyclectomy. Histopathologically the neoplasm was composed of both pigmented and non-pigmented cells. Pseudoacini, containing acid mucopolysaccharides, were present throughout the tumour matrix. Electron microscopically the non-pigmented cells were found to possess a convoluted plasmalemma, abundant rough endoplasmic reticulum, and numerous desmosomes and gap junctions. The pigmented cells contained large, round, mature melanosomes, occasional premelanosomes, and desmosomes, which resembled the posterior pigment epithelium of the iris. The intercellular matrix contained fine collagen fibrils resembling vitreous. We believe that this neoplasm represents a congenital adenoma of the ciliary body and iris.

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.

Hamartomatous adenoma of the nonpigmented ciliary epithelium arising in iris-ciliary body coloboma. Light and electron microscopic observations

A 2 1/2-year-old boy had a slowly enlarging mass at the site of a typical iris-ciliary body coloboma for 2 years. The mass was excised partially by iridocyclectomy. By light microscopy, the tumor cells were embedded in a rich mucoid stroma that contained abundant hyaluronidase-sensitive acid mucopolysaccharides. By electron microscopy the tumor showed light and dark cells with interdigitating cell membranes, desmosomes, gap junctions, multilaminar basement membrane, and numerous extracellular collagen fibrils that resembled vitreous fibrils. We believe that the tumor represents a hamartomatous (congenital) adenoma of the nonpigmented ciliary epithelium rather than a conventional (acquired) adenoma, since it developed precisely within a colobomatous defect of the iris and ciliary body.