Choroidal Melanoma Cells Research Articles

Tissue culture of human choroidal melanoma cells obtained by fine-needle aspiration biopsy.

The optimal treatment of choroidal melanoma is controversial. Many patients are now being treated with nonenucleation therapies. Fine-needle aspiration biopsy of intraocular tumors may well prove to be safe; we used a needle biopsy technique on three freshly enucleated globes and established choroidal melanoma cell lines in culture from these specimens. This report describes our needle biopsy and tissue culture techniques.

A New Instrument for Cryoenucleation

It has been proposed that choroidal malignant melanoma cells may be disseminated through the systemic circulation at the time of enucleation and lead to metastatic disease. Immobilization of tumor cells by freezing the base of the tumor during enucleation (cryoenucleation) has been suggested, but previous instrumentation has been difficult to apply without freezing surrounding orbital tissues. The Gallie Cryoenucleator insulates adjacent tissues while liquid nitrogen (–196°C) to the sclera. Intraoperative ultrasound assures accurate placement of the Cryoeriucleator under the tumor base and permits the depth of freeze to be monitored. The instrument has been used to facilitate cryoenucleation in 43 eyes containing choroidal malignant melanomas over the past 5 years. Five patients have developed metastatic disease, which became apparent 12 to 42 months post-cryoenucleation. Although it is not known if cryoenucleation does prevent metastasis of choroidal melanoma, the Cryoenucleator provides a simple and safe way to apply this theoretically beneficial technique.

Antibodies to skeletal muscle actin and their reactivity with malignant melanoma of the choroid.

Imprints of choroidal malignant melanoma cells were treated with serum containing antibodies to a purified preparation of actin derived from skeletal muscle. Evidence of a positive reaction, as shown by indirect immunofluorescence, substantiated an impression based on morphological criteria that choroidal melanoma cells contain actin protein. The significance of this protein in tumour biology is discussed, and a possible interference by antiactin antibodies in the immunodiagnosis of choroidal melanoma is highlighted.

Contractile protein antigens in the cells of malignant melanoma of the choroid and their diagnostic significance.

Sera from patients with proved and suspected melanoma of the uvea and from patients with innocuous uveal naevi were found by immunohistological techniques to have an affinity for the cytoplasm of malignant choroidal melanoma cells in an appreciable proportion of cases. The responsible antibodies were subsequently shown to react with smooth muscle protein in a variety of tissues and not to be melanoma-specific. It was also shown by electron microscopy that microfilaments consistent with contractile protein are a feature of the cytoplasm of malignant choroidal melanoma cells. The latter observations, which do not appear to have been reported previously, mean that false positives are to be expected if immunodiagnostic techniques are used for the recognition of malignant disease of the uvea, especially as smooth muscle antibodies can occur in non-neoplastic ocular diseases.

Orbito-ocular tumors in Nigeria.

This study describes 191 histologically proven orbito-ocular tumors in Nigerians. More than two thirds of all the tumors occurred in patients under the age of 20 years. The majority of tumors encountered were retinoblastomas and Burkitt's lymphoma of the orbit, which occurred in children. Malignant choroidal melanoma and basal cell carcinoma of the lids are relatively uncommon, but squamous cell carcinoma of the conjunctiva and pseudotumor of the orbit were not uncommon. Similarities in frequencies of tumor types among various African populations are noted, and differences observed between African and Caucasian population groups are discussed.