Experimental ocular malignant melanoma in Sinclair swine

The Behavior of Two Cell Lines Obtained from Murine (B16-F10) and Human (G-361) Melanomas Implanted into the Eyes of New Zealand White Rabbits, and their Microscopic, Immunohistochemical and Ultrastructural Appearances

A transcleral inoculation of 15x10(6) melanocytes of the B16-F10 and G-361 cell lines was carried out in the anterior chamber of one eye in New Zealand white rabbits. Tumor growth occurred in 24 eyes (77%) of the B16-F10 group and in 22 (73%) of the G-361 group. The tumors of the latter group were mostly amelanic and showed local aggression with ocular perforation and extrascleral growth one month post-implant, while the tumors of the B16-F10 group were intensely pigmented and grew over the iris although they did not perforate the eyeball. Microscopically, the tumors of both groups were of the mixed type, made up of epithelioid and fusiform melanocytes. S-100 protein and Nki C3 monoclonal immunohistochemical techniques showed a positive immunoreaction in all cases of tumor growth. Ultrastructurally, the G-361 melanocytes showed a few melanosomes corresponding to maturity state II and, occasionally, state III, while totally melanized state IV cells predominated in the B16-F10 group. Aberrant melanosomes were common in both groups. The inoculation of 15x10(6) melanocytes of either cell line was useful to produce ocular melanomas.

Comparative study of experimental ocular melanoma using two implantation techniques of B16-F10 melanocytes

OBJECTIVE

The aim of this work was to evaluate the behaviour of B16-F10 melanoma cell cultures implanted in the anterior chamber of the eye of New Zealand white rabbits by studying the clinical-pathological and ultrastructural characteristics of the lesions.

METHODS

One group (A) (consisting of 30 rabbits) was transclerally inoculated (1 mm from sclero-corneal limbus) with 4 x 10(6) melanocytes and another group (B) (also 30 animals) was inoculated once per week for 3 consecutive weeks with 5 x 10(6) cells (total 15 x 10(6)); 30 animals acted as the control group (C). All the lesions were processed for optic and electronic microscopy.

RESULTS

Tumoral growth in group A was 43% (13/30) and in group B 80% (24/30). All lesions were pigmented and none perforated the eyeball. Microscopically, they were a mixture of epithelioid and fusiform cells disposed around the blood vessels. Ultrastructurally, the presence of melanosomes in different stages of maturation and aberrant melanosomes were characteristic.

CONCLUSION

We suggest that the transcleral inoculation of 15 X 10(6) B16-F10 melanocytes into the anterior chamber of the eye of New Zealand white rabbits may be a valid and reproducible method for obtaining an experimental ocular melanoma model.