Inflammatory juvenile compound nevi: A melanoma is not all that it appears to be. / Nevus compuesto inflamatorio juvenil: no es melanoma todo lo que parece.

An 11 year-old girl presented with a recent growth pigmented conjuntival lesion in the bulbar conjunctiva of left eye. Due to the the biomicroscopic and ultrasound findings, an excisional biopsy was performed on the lesion using the «no touch¼ technique, as well as cryo-coagulation of surgical margins. Histopathological examination revealed an inflammatory compound nevus. Melanotic conjunctival tumours are mostly benign. However, the recent growth of a lesion, its vascularisation, irregularities of the margins, and colour change must suggest it has turned malignant. In such case, excision of the lesion is mandatory. Despite all the clinical changes, especially in young patients, it can still be an inflammatory compound nevus.

Retinoblastoma in the adolescent. Unusual clinical and histopathology findings.

CASE REPORT: A 17-year- old male with 2years history of an intraocular mass and progressive visual loss of the left eye. Spontaneous sclera rupture occurred during enucleation. Microscopic evaluation with H-E, PAS and immunohistochemistry (NSE, GAFP, SYN, CD99) revealed a small blue round cell malignant neoplasm with extensive necrosis and apoptosis. The optic nerve, ciliary body, choroid, anterior chamber, and sclera were infiltrated. SYN was positive and CD99 was negative in neoplastic cells, consistent with a poorly differentiated retinoblastoma. DISCUSSION: Retinoblastoma is the most frequent primary intraocular malignant tumour in childhood, but occasionally older patients can be affected. Immunohistochemistry is mandatory in poorly differentiated retinoblastomas.

Intravitreal memantine retinal toxicity in rabbits.

OBJECTIVE: To histologically evaluate whether the intravitreal application of memantine produces retinal toxicity in rabbits. METHODS: A cross-sectional design, experimental, descriptive study was performed on 16 eyes of 16 New Zealand rabbits of 3 kg, divided in 4 groups of 4 rabbits. A dose of 70 ng/ml of intravitreal memantine was administered in Group A, a dose of 150 ng/ml in Group B, a dose of 400 ng/ml in Group C, and Group D received 1 ml of balanced salt solution. The injected eye of half of each group was enucleated 15 days after the injection, and the rest within 30 days after injection. Following enucleation, each eye was placed in 10% formaldehyde. Histopathological analysis was performed on all enucleated eyes. The animals were treated according to the guidelines of the Association for Research on Vision and Ophthalmology (ARVO). RESULTS: Groups A, B and D did not show any histopathological changes after their enucleation at 15 and 30 days. Group C showed changes in the photoreceptor layer after enucleation at 15 and 30 days. CONCLUSIONS: In our study, it was observed that memantine concentrations at 70 ng/ml and 150 ng/ml are safe when administered intravitreally; however, doses of 400 ng/ml produced retinal structural changes. This research should continue to assess its clinical usefulness.