A disc-shaped flat, heavily pigmented tumour (5 mm diameter) was discovered at the retinal periphery in a glutaraldehyde fixed eye which was enucleated in treatment of a peripapillary melanoma in a 60 year old man. The macroscopic appearances of the peripheral lesion were identical to those described in clinical reports as "Congenital Hypertrophy of the RPE". By light microscopy and transmission electron microscopy the hamartoma consisted of a hypertrophic and hyperplastic layer of RPE cells beneath an atrophic outer retina. The hyperplastic RPE cells did not contain lipofuscin and the content and size of the abnormal melanin granules increased towards the retinal aspect. The cells were linked by complex process interdigitations and attachments; the intercellular spaces contained basement membrane material and 100 nm banded collagen. Large vacuolar structures were prominent in the cells adjacent to the normal choriocapillaris. In the RPE cells at the periphery there was an excess lipofuscin and here there were recognisable outer segments. The morphological pattern suggested that this lesion should be considered as a congenital hypertrophy of the RPE which has progressed to focal segmental hyperplasia and focal atrophy.

Eye Neoplasms↗

PubMed1977

[Alterations in the metabolism of cornmeal epithelium during medium-term storage (author's transl)].

Freshly prepared bovine corneas were stored in medium TC 199 with penicillin and fetal calf serum at +4 degrees C over a storage period of 168h. Every 24h, the levels of glucose, lactate, and pyruvate in the corneal epithelium were estimated. Also the glucose levels in the corneal epithelium and stroma were compared at the same time intervals. Furthermore, alterations in the enzyme pattern of the epithelial cells during storage were observed.

Animals↗