Clinicopathologic and molecular analysis of a choroidal pigmented schwannoma in the context of a PTEN hamartoma tumor syndrome.
; ; DEPREZ, Manuel et al
in Ophthalmology (2012), 119(4), 857-64
PURPOSE: To report the first case of choroidal schwannoma in a patient affected by PTEN hamartoma tumor syndrome (PHTS) and investigate the molecular involvement of the phosphatase and tensin homolog ... [more ▼]
PURPOSE: To report the first case of choroidal schwannoma in a patient affected by PTEN hamartoma tumor syndrome (PHTS) and investigate the molecular involvement of the phosphatase and tensin homolog (PTEN) and neurofibromin 2 (NF2) genes in this rare intraocular tumor. DESIGN: Observational case report. PARTICIPANT: A 10-year-old girl diagnosed with PHTS. METHODS: The enucleated specimen underwent histologic, immunohistochemical, and transmission electronic microscopy. The expression of PTEN and NF2 and their protein products were evaluated by reverse transcription-polymerase chain reaction and immunohistochemistry. Somatic mutations of PTEN and NF2, as well as allelic loss, were investigated by direct sequencing of DNA extracted from the tumor. PTEN epigenetic silencing was investigated by pyrosequencing. MAIN OUTCOME MEASURES: Histopathologic and molecular characterization of a choroidal pigmented schwannoma. RESULTS: Histopathologic, immunohistochemical, and electron microscopic analysis demonstrated features consistent with a pigmented cellular schwannoma of the choroid. We found no loss of heterozygosity at the genomic level for the PTEN germline mutation and no promoter hypermethylation or other somatic intragenic mutations. However, we observed an approximate 40% reduction of PTEN expression at both the mRNA and the protein level, indicating that the tumor was nonetheless functionally deficient for PTEN. Although DNA sequencing of NF2 failed to identify any pathologic variants, its expression was abolished within the tumor. CONCLUSIONS: We report the first description of a pigmented choroidal schwannoma in the context of a PHTS. This rare tumor showed a unique combination of reduction of PTEN and absence of NF2 expression. [less ▲]Detailed reference viewed: 15 (0 ULg)
Collagen, factor VIII antigen, and immunoglobulins in the human aqueous drainage channels.
; ; Foidart, Jean-Michel et al
in Ophthalmology (1980), 87(4), 337-45
Twenty-five trabeculectomy specimens from patients with primary open angle glaucoma and chronic angle closure glaucoma, and 11 age-matched controls were examined by immunofluorescence and immunoperoxidase ... [more ▼]
Twenty-five trabeculectomy specimens from patients with primary open angle glaucoma and chronic angle closure glaucoma, and 11 age-matched controls were examined by immunofluorescence and immunoperoxidase techniques to determine the types of collagen, immunoglobulins, and the presence of factor VIII-related antigen in the human aqueous drainage channels. In the glaucoma cases and in controls, we demonstrated that the electron dense basement membrane-like material in the peripheral portion of the trabecular beams and in the juxtacanalicular meshwork, consists at least in part, of type IV collagen, a noncollagenous protein ("laminin") and fibronectin. Factor VIII-related antigen was demonstrated in conjunctival vessels of the control eyes. Schlemm's canal and the trabecular endothelial cells did not stain for factor VIII-related/antigen in any of the specimens examined. No deposits of IgA, IgM, IgG, and the C3 component of complement were detected in the aqueous drainage channels. [less ▲]Detailed reference viewed: 28 (0 ULg)