Adenoma of the pigmented ciliary epithelium: ultrastructural and immunohistochemical findings

Clinical and histopathological features of adenomas of the ciliary pigment epithelium

PURPOSE

Adenomas of the ciliary pigment epithelium (CPE) are rare benign tumours which have mainly to be differentiated from malignant ciliary body melanomas. Here we report on a consecutive series of patients with CPE adenomas and describe their characteristics.

METHODS

The retrospective hospital-based case series study included all patients who were consecutively operated for CPE adenomas.

RESULTS

Of the 110 patients treated for ciliary body tumours, five patients (4.5%) had a CPE adenoma. Mean age was 59.0 ± 9.9 years (range: 46-72 years). Mean tumour apical thickness was 6.6 ± 1.7 mm. Tumour colour was mostly homogenously brown to black, and the tumour surface was smooth. The tumour masses pushed the iris tissue forward without infiltrating iris or anterior chamber angle. Sonography revealed an irregular echogram with sharp lesion borders and signs of blood flow in Color Doppler flow imaging. Ultrasonographic biomicroscopy demonstrated medium-low internal reflectivity and acoustic attenuation. In magnetic resonance imaging (MRI), the tumours as compared to brain were hyperintense on T1-weighted images and hypointense on T2-weighted images. Tumour tissue consisted of cords and nests of pigment epithelium cells separated by septa of vascularized fibrous connective tissue, leading to a pseudo-glandular appearance. The melanin granules in the cytoplasm were large and mostly spherical in shape. In four patients, the tumours were hyperpigmented. Tumour cells were large with round or oval nuclei and clearly detectable nucleoli.

CONCLUSIONS

These clinical characteristics of CPE adenomas, such as homogenous dark brown colour, smooth surface, iris dislocation and anterior chamber angle narrowing but no iris infiltration, segmental cataract, pigment dispersion, and, as compared to brain tissue, hypointensity and, as compared to extraocular muscles or lacrimal gland, hyperintensity on T2-weighted MRI images, may be helpful for the differentiation from ciliary body malignant melanomas.

Axons in human choroidal melanoma suggest the participation of nerves in the control of these tumors

PURPOSE

To furnish morphologic evidence of autonomic nervous system influence on choroidal melanoma.

DESIGN

Histopatholgic case report.

METHODS

In the enucleated eye of a 72-year-old woman, portions of a mixed-cell choroidal melanoma were processed for electron microscopy, and ultrathin sections were screened painstakingly under magnifications of x13,000 and x23,000.

RESULTS

The connective tissue of the melanoma contained macrophages, blood vessels, and profiles of several nonmyelinated nerve fiber bundles with a maximum of 6 axons.

CONCLUSION

The existence of axons in neoplastic tissue indicates nervous input and/or output. This led us to conclude that the reaction of the melanoma is subjected to vegetative influences, yet to an unknown extent.