[Corneal macular dystrophy: clinical, histopathologic and ultrastructural features]. / Distrofia macular corneal: características clínicas, histopatológicas y ultraestructurales.

OBJECTIVE: To assess the main clinical, genetic, histopathological and ultrastructural features of Mexican patients with macular corneal dystrophy, and to compare the results with those previously reported. METHOD: We analyzed six cases where a histopathologic diagnosis of macular corneal dystrophy had been made between 1957 and 2004. RESULTS: Clinically, all corneas showed focal grayish-white stromal opacities with diffuse edges. Histopathologically, intrastromal granules stained strongly positive with Alcian blue and colloidal iron. Transmission electron microscopy showed enlargement of smooth endoplasmic reticulum and the presence of intracytoplasmic vacuoles that corresponded to glycosaminoglycans. Genetic analysis showed novel mutations in the CHST6 gene in 2 of the patients. CONCLUSIONS: Females were more affected than males and the mean age at the time of diagnosis was older than that reported previously, however the clinical, histopathological and ultrastructural features were similar to those of previous reports. As described in other cases in the literature, in some instances a disorder is found in CHST6 gene as a basis for this condition.

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.

Lesions of the lacrimal caruncle. Clinicopathologic features.

PURPOSE: The rarity of lesions of the lacrimal caruncle, in addition to their wide variety of histopathologic types, makes an accurate clinical diagnosis difficult. To comprehensively illustrate the clinical and histopathologic features of these lesions, the authors conducted a retrospective analysis of all caruncular lesions that underwent biopsy at a large referral ophthalmologic hospital during a 33-year period. METHODS: The files of the Laboratory of Pathologic Anatomy from July 1957 through July 1990 were reviewed. The slides of 113 cases were reviewed and classified in two main categories: (1) inflammatory lesions and (2) neoplasms and pseudoneoplasms. The age and sex of the patient as well as preoperative clinical diagnosis were analyzed. RESULTS: Among the 113 patients whose surgical specimens were evaluated, there were 44 males and 69 females. The mean age was 31 years. The clinical diagnosis was accurate in only 50% of the patients. The authors found 16 different histopathologic types of lesions. Nevi accounted for 34% and papillomas for 26% of the total analyzed lesions. Only 5.3% of the lesions were found to be malignant. CONCLUSION: In this series, the authors confirm the low frequency of caruncular lesions, as well as their wide variety of histopathologic types. The authors found a wide range of ages and a slight female predominance. Nevi and papillomas were the most frequent lesions, and clinically they were properly diagnosed in most of the cases. Although malignancy was uncommon, it was suspected in only half of the cases.

Taenia crassiceps: experimental model of intraocular cysticercosis.

An experimental model of Taenia crassiceps intraocular cysticercosis was developed in rabbits. The objectives of this study were to analyze the pathophysiology of this parasitic infection and to evaluate the humoral immune response. Cysticerci, inoculated in the anterior chamber of the eye, were able to grow; no inflammatory changes in the eye or anticysticercus antibodies in serum or in aqueous humor were detected during the 12-day period. In contrast, rabbits that had previously been either infected intraperitoneally with living T. crassiceps cysts or immunized intramuscularly with T. crassiceps antigenic extract developed an intense inflammatory reaction in the eye and high levels of antibodies were detected in serum and aqueous humor even before the intraocular inoculation of parasites. Furthermore, intraocular cysticerci showed minimal growth and some were eliminated. These findings support the concept that the eye is an immunologically privileged site in the nonimmunized host and the importance of the immune response in the elimination of this parasitic infection.