97th DOG Annual Meeting 1999
FAILURE OF THE TRANSPUPILLARY THERMOTHERAPY IN THE TREATMENT OF CHOROIDAL MELANOMA
S. Pfennigsdorf*, V. Krenn**
Background: The transpupillary thermotherapy (TTT) is a new treatment especially for flat, central choroidal melanomas. It can be performed easily and without severe complications. So far, only a few treated eyes were examined histopathologically. Aim of this case report is the correlation between the clinical and histopathological findings.
Case report: A 71 year-old woman was treated with the diode laser (wavelength: 810 nm) 7 times for a parapapillary choroidal melanoma. The tumor measured 7.5 x 7.0 mm at its base and 2.4mm in height (sonographic measurements). In every session 7-9 effects with a diameter of 2-3mm and an energy of 350-400 mW were applied for 1 minute each. After that time the tissue turned grayish due to an edema. The visual acuity remained constant at 60/200. 6 weeks after the therapy the tumor remained constant. Another four weeks later the melanoma had grown significantly (base: 9.4 x 8.0 mm; height: 4.2 mm; (sonographic measurements)), it also showed infiltration of the sclera. Enucleation was performed.
Histology: Macroscopic and microscopic examination showed no extraocular extension of the melanoma. The tumor had a heterogenous appereance. The inner tumor cells presented with tumor necrosis including cell necrosis, melanophages and secondary fibrotic changes. In the outer tumor parts an active melanoma could be found. The tumor was pigmented and contained many epitheloid cells. An infiltration of the inner sclera and emissary vessels was seen.
Summary: Transpupillary thermotherapy requires close follow-up. In case of a tumor growth or insignificant regression of the melanoma an additional therapy (brachytherapy, proton beam irradiation or enucleation) must be performed. Perhaps the generally adviced application-time of one minute is not enough to produce a complete necrosis in the deep portions of the tumor.
*Dept. Ophthalmology and ** Dept. Pathology, Julius-Maximilians-University Würzburg