CORONAL ADENOMA
The coronal adenoma, also called benign adenoma, Fuch’s adenoma, Fuch’s epithelioma, and epithelial hyperplasia, is the most common intraocular tumor. [6,
7] These adenomas originate from the nonpigmented epithelium of the pars plicata (the coronal processes) (Figure 5-6). They occur more commonly in older individuals. [
8] Histologic sections show nonpigmented ciliary epithelium embedded in a matrix of basement membrane material (Figure 5-7). Rarely, these tumors are clinically misdiagnosed as melanoma because they indent the iris and mimic a pigmented lesion. [
9,
10]Aspiration biopsy will distinguish melanoma from coronal adenoma. Fine needle aspiration of coronal adenomas has revealed cohesive groups of nonpigmented epithelium with bland nuclei and abundant cytoplasm clustered around extracellular matrix material (Figure 5-8). [
11] Ultrastructural and immunohistochemical studies indicate that the extracellular matrix material contains Type IV collagen. [
12]
LEIOMYOMA
Leiomyomas of the ciliary body are rare. [
13,
14,
15, 16,
17,
18] They presumably arise from ciliary muscle. The clinical diagnosis may be suggested by augmented transillumination. Electron microscopic identification of myofilaments and micropinocytotic vesicles differentiates these tumors from neurofribromas and schwannomas.
Mesectododermal leiomyomas of the ciliary body are extremely rare. [
19] Fine needle aspiration characteristics of these tumors have not been reported previously. We reviewed a fine needle aspiration of one such tumor from the UCLA cytology archives. The aspirate shows tight clusters of spindle and oval cells in a fibrillary background. The nuclei are extremely bland with inconspicuous nucleoli (Figure 5-9). Sections reveal an amelanotic ciliary body mass with prominent vascularity, a fibrillary and myxoid background, and individual tumor cells that are both spindled and oval shape (Figure 5-10 and 5-11). These findings suggest a neural tumor, yet electron microscopy shows smooth muscle differentiation. [
20]
MELANOCYTOMA
Melanocytoma is a benign lesion found most commonly in blacks. [
21,
22] It may be found in any part of the uveal tract, but is generally present adjacent to the optic disc. Melanocytomas occasionally occur in the ciliary body. [
23] The cells of a melanocytoma are large with abundant densely pigmented cytoplasm and round nuclei with small nucleoli (Figure 5-12).
ADENOMA AND CARCINOMA OF THE PIGMENTED CILIARY EPITHELIUM
Adenomas of the pigmented ciliary epithelium may clinically mimic ciliary body melanomas because they are densely pigmented (Figure 5-13). [
24,
25,
26] In general, they tend to be only locally invasive. [
27] Immunohistochemical studies suggest that the tumor arises from the pigmented ciliary epithelium. [
28] Histologically, the tumor replaces the ciliary body and is composed of large pigmented cells arranged in a nodular pattern (Figure 5-15). Cytologic findings include large cell with abundant intracellular and extracellular pigment, and round nuclei without prominent nucleoli. [
29]
References:
6. Fuchs E. Anatomische miscellen. Albrecht Von Graefes Arch Klin Ophthalmol 1883;29:209.
7.
Bateman JB, Foos RY. Coronal adenomas. Arch Ophthalmol 1979;97:2379-2384.
8.
Iliff W, Green WL. The incidence and histology of Fuchs’ adenoma. Arch Ophthalmol 1972;88:249-254.9.
Burch PG, Maumenee AE. Iridocyclectomy for benign tumors of the ciliary body. Am J Ophthalmol 1967;63:447-452.10.
Zaidman GW, Johnson BL, Salamon SM, Mondino BJ. Fuch’s adenoma affecting the peripheral iris. Arch Ophthalmol 1983;101:771-773.11.
Glasgow BJ. Intraocular fine needle aspiration biopsy of coronal adenomas. Diagn Cytopathol 1991;7:239-242.12.
Brown HH, Glasgow BJ, Foos RY. Coronal adenomas: ultrastructural and immunohistochemical features. Am J Ophthalmol 1991;112:34-40.13.
Blodi FC. Leiomyoma of the ciliary body. Am J Ophthalmol 1950;33:939-942.14.
Bonamour MM, Bonnet JC, Jambon M. Leiomyome du corps ciliaire; quelques considerations a propos du diagnostic et du traitement des tumeur benignes de l’iris et du corps ciliaire. Bull Soc Ophtalmol Fr 1957;7-8:482.15.
Calmettes L, Deodati F, Bec P. Leiomyome du corps ciliare. Bull Soc Ophtalmol Fr 1961;74:158-168. 16. Allen RA. Leiomyoma of ciliary body. Case presented at the Verhoeff Society, Washington, D.C., April 24-27, 1967. 17. Meyer SL, Fine BS, Front RL, Zimmerman LE. Leiomyoma of the ciliary body. Electron microscopic verification. Am J Ophthalmol 1968;66:1061-1068.
18. Calhoun FP Jr. Leiomyoma of the ciliary body. Case presented at the Verhoeff Society, Washington, D.C., April 26-29, 1976. 19. Jakobiec FA, Font RL, Tso MOM, Zimmerman LE. Mesectodermal leiomyoma of the ciliary body. A tumor of presumed neural crest origin. Cancer 1977;3 9:2102-2113. 20. Jakobiec FA, Iwamoto T. Mesectodermal leiomyoma of the ciliary body associated with a nevus. Arch Ophthalmol 1978;96:692-695. 21. Zimmerman LE. Melanocytes, melanocytic nevi, melanocytomas. Invest Ophthalmol 1965;4:11-40.22.
Reidy JJ, Apple DJ, Steinmetz RL, et al. Melanocytoma nomenclature, pathogensis, natural history and treatment. Surv Ophthalmol 1985;29:319-327.
23.
Frangieh GT, El Baba F, Traboulsi El, et al. Melanocytoma of the ciliary body: presentation of four cases and review of nineteen reports. Surv Ophthalmol 1985;29:328-334. 24.
Streeten BW, McGraw JL. Tumor of the ciliary pigment epithelium. Am J Ophthalmol 1972;74:420-429.
25.
Wilensky JT, Holland MG. A pigmented tumor of the ciliary body. Arch Ophthalmol 1974;92:219-220.26.
Chang M, Shields JA, Wachtel DL. Adenoma of the pigment epithelium of the ciliary body simulating a malignant melanoma. Am J Ophthalmol 1979;88:40-44. 27.
Anderson SR. Medulloepithelioma of the retina. In: Zimmerman LE, ed. Tumors of the eye and adnexa. Int Ophthalmol Clin 1962;2:483-506.
28.
Leib WE, Shields JA, Eagle RC, Kwa D, Shields CL Cystic adenoma of the pigmented ciliary epithelium. Ophthalmol 1990;97:1489-1493.
29.
Char DH, Miller TR, Crawford JB. Cytopathologic diagnosis of benign lesions simulating choroidal melanomas. Am J Ophthalmol 1991;112:70-75.
