M N Burnier

Uveal Melanoma: Comparison of the Prognostic Value of Fibrovascular Loops, Mean of the Ten Largest Nucleoli, Cell Type, and Tumor Size

PURPOSEnThis study was performed to determine the prognostic significance of the presence of loops defined as periodic acid-Schiff-positive fibrovascular septa that completely surround lobules of tumor cells in cases of uveal melanoma.nnnMETHODSnThe presence of loops was evaluated using an ordinary light microscope and routinely stained periodic acid-Schiff and hematoxylin sections from 496 posterior uveal melanomas without knowledge of the follow-up data on the patient.nnnRESULTSnAt 15 years, survival decreased from 67.5% to 33.8% when complete loops were present. Univariate Cox regression analysis indicated that the presence of loops was an indicator of poor outcome, and was better than age but not as good as the mean diameter of the largest nucleoli, cell type, or tumor size.nnnCONCLUSIONSnThe presence of loops, as evaluated in this study, was not as strong an indicator of poor outcome as were loops assessed in a previous study of 234 cases from another laboratory. The authors suspect this difference may be due to their only using routinely stained sections without a green filter, as was used in previously reported studies. The authors description of loops does not require any special equipment and gives sufficiently useful results to justify its inclusion by the pathologist in reports of such specimens. A description of vascular loops should be added to the use of the modified Callender cell type, tumor dimensions, mitotic count, extraocular extension, and lymphocytic infiltration in the final pathologic report.

Identification of Toxoplasma gondii in Paraffin-Embedded Sections by the Polymerase Chain Reaction

We used the polymerase chain reaction to amplify DNA fragments specific to Toxoplasma gondii. The sensitivity of the technique allowed for the detection of as few as ten cultured T. gondii tachyzoites. We applied the same amplification technique to deparaffinized ocular sections from two cases of ocular toxoplasmosis. Although toxoplasmic cysts could only be seen in one eye by optical microscopy, polymerase chain reaction allowed the identification of the parasite in both cases. Our study indicates the feasibility of a sensitive DNA-based assay to complement pathologic studies of an ocular parasitic disease.

Immunohistochemical evaluation of uveal melanocytic tumors. Expression of HMB‐45, S‐100 protein, and neuron‐specific enolase

The authors compared the immunohistochemical reactivity of 13 uveal nevi and 20 uveal melanomas for HMB‐45, S‐100 protein, and neuron‐specific enolase (NSE) in formalin‐fixed, paraffin‐embedded sections. All 33 of the lesions were positive for HMB‐45. The false‐negative rates for S‐100 protein and NSE were 21% and 18%, respectively. If only strongly positive reactions were considered, more than 50% of the tumors would be interpreted as negative for S‐100 protein and NSE. Nevi stained with less intensity than melanomas using all three antibodies. The expression of HMB‐45 appeared to be greater in active nevi than in inactive nevi. There was a weak association between S‐100 protein reactivity and the ability of the uveal melanomas to metastasize (P = 0.1); however, the standard deviation of nucleolar area was a much better predictor (P = 0.02). These results indicate that pathologists will find HMB‐45 to be a useful tool in differentiating uveal melanoma from nonmelanocytic tumors.

Histopathologic study of the molteno glaucoma implant in three patients

Three eyes with the Molteno glaucoma implant (one eye with epithelial downgrowth, one eye with iridocorneal endothelial syndrome, and one eye with aphakia and glaucoma) were enucleated two to six years after implantation. Histopathologic examinations disclosed no evidence of erosion of sclera or conjunctiva of the eye by the glaucoma implant device. In the outer layers of the bleb wall, few and mostly degenerated inflammatory cells were present, which represented a minimal inflammatory reaction. Scanning electron microscopy of the tubes in these three patients showed that the tube was intact, patent, and without signs of degradation. The tube entering into the anterior chamber caused no appreciable inflammation and maintained its patency even when downgrowth epithelial cells lined the anterior chamber. The Molteno plate induced little or no inflammatory reaction. Therefore, the Molteno glaucoma implant is a useful device for patients with high risk for failure after surgery for glaucoma.

Choroidal malignant melanoma in association with oculodermal melanocytosis in a black patient.

Oculodermal melanocytosis (ODM) is a congenital melanocytic hyperpigmentation of the face and ocular tissues. The eponym naevus of Ota as described by Otal has been used interchangeably with ODM and ocular melanosis (OM) in many reported cases. The original definition by Ota included patients with and without ocular involvement. For these reasons, we will refer to the term oculodermal melanocytosis, as suggested by Fitzpatrick2 to describe this patients condition.

TGFBI gene mutations in Brazilian patients with corneal dystrophy

PurposeTo investigate the transforming growth factor beta-induced gene (TGFBI) mutations in Brazilian patients with corneal dystrophy and to evaluate the phenotype–genotype correlation in these patients.MethodsA total of 11 unrelated families were studied. The diagnosis of corneal dystrophy was based on clinical and histopathological findings. Genomic DNA was extracted from peripheral blood leucocytes, and exons 4 and 12 of the TGFBIgene were amplified by polymerase chain reaction followed by direct sequencing on both strands.ResultsFive different mutations in the TGFBIgene were found in the probands. We identified the following mutations: lattice corneal dystrophy—R124C and A546T; Reis-Bücklers corneal dystrophy—R555Q and R124L; granular corneal dystrophy—R555W and Avellino dystrophy—R555W. In three of the 11 studied families there was no mutation in exons 4 and 12.ConclusionsThis is the first report of mutations in the TGFBIgene in a series of Brazilian patients with corneal dystrophy. The findings indicate that TGFBIgene screening should be considered in the diagnosis of corneal dystrophy.

Dracunculiasis of the Orbit and Eyelid: Light and Electron Microscopic Observations of Two Cases

Dracunculiasis, an infection caused by the nematode parasite, Dracunculus medinensis, usually affects the skin and subcutaneous tissue. The authors studied two cases of dracunculiasis involving the orbit and eyelid in African children. In the first case, the patient presented with proptosis and the clinical diagnosis was Burkitts lymphoma. In the second patient, the eyelid lesion was diagnosed as a dermoid cyst. Histopathologically, the orbital lesion showed a degenerated and partially calcified worm within a large intraconal abscess. The eyelid lesion contained a well-preserved gravid female worm filled with larvae. The results of transmission and scanning electron microscopic studies are discussed.

Pesquisa de células malignas circulantes em pacientes com melanoma maligno de coróide

PURPOSE: The purpose of our study was to detect circulating malignant cells (CMCs) in oversea-shipped blood samples of patients with uveal melanoma diagnosed in Brazil. METHODOS: Melan-A and tyrosinase were the two markers used for the detection of CMCs, using reverse transcriptase nested polymerase chain reaction (RT-nested-PCR) in 6 patients with uveal melanoma. The expression of b-actin and GAPDH were used to assess the quality of the material. RESULTS: Five patients (83.33%) tested positive for the presence of CMCs. The RT-nested-PCR was positive for melan-A in 4 patients (66.7%) and positive for tyrosinase in 4 (66.7%) of the 6 patients. Three (50%) patients were positive for both markers. One (16.7%) patient was negative for both markers. All negative controls were negative. CONCLUSION: The quality of the blood samples shipped overseas, from patients with uveal melanoma, was preserved. The detection of CMCs using RT-nested-PCR was positive in the majority of the patients.

Bilateral progressive necrotizing retinochoroiditis in an immunocompromised patient: histopathologic diagnosis – authors reply

Editor, W e are glad that our manuscript (Belfort et al. 2008) interested some of your readers. Toxoplasmic retinochoroiditis still has its mysteries, and the understanding of the morphological changes is a way to enlighten this matter. It appears that three issues in our publication deserve further clarification (Vasconcelos-Santos et al. 2009). First, the term ‘necrosis of Bruch’s membrane’ was questioned. Perhaps the term necrosis should not be used for an acellular structure. However, the inner layer of the Bruch’s membrane is the basement membrane of the retinal pigment epithelium (RPE), being secreted by it. The extracellular accumulation of the eosinophilic material is likely because of the death of RPE cells, so the term necrosis is still preferable. Nevertheless, it is also possible that some degradation of the elastic and collagen layers of Bruch’s membrane may contribute to the composition of those necrotic debris, a theory that has yet to be tested. Necrobiosis is also a term that has been used by some authors to describe this phenomenon. Second, it was stated that ‘RPE necrosis...has been recognized not only in cases of toxoplasmic retinochoroiditis but also in other necrotizing retinites secondary to mycobacteria, fungi, viruses and even in primary retinal lymphoma’. A very important distinction shall be made here. Those deposits should never be confused with the malignant necrotic cells from large B-cell lymphomas of the retina and CNS, which represents a totally different pathological process (McLean et al. 1993). Even though RPE necrosis is indeed seen in necrotizing retinitis from other aetiologies, the deposits of necrotic material between Bruch’s and the RPE are preferably, if not exclusively, seen only in cases of toxoplasmosis. We presented a representative image of those deposits that are not found in other aetiologies, even when extensive RPE necrosis is present. The publication from Rao et al. 2006 beautifully illustrates the distribution of Mycobacterium tuberculosis in the RPE, but the deposits we referred to in our report were not seen. The origin and composition of those deposits is currently the subject of some studies in our laboratory. We are in the process of compiling a larger number of eyes in order to perform immunohistochemical and ultrastructural studies in this regard. At last, the authors contested our suggestion that focal disruptions of Bruch’s membrane partially explain why an inflammatory process that starts in the retina spreads to the choroid. We should respectfully say that their argument on the contrary is rather weak. First, the fact that ‘secondary inflammation of the choroid occurs despite an uninterrupted Bruch’s membrane’ does not exclude such possibility. Second, it is unsure how true this statement would be because the integrity of the entire Bruch’s membrane in those cases is practically impossible to be determined. All the causes of necrotizing retinochoroiditis release numerous cytotoxins and lytic enzymes that weaken and degrade acellular structures such as the Bruch’s membrane. Focal disruptions of Bruch’s would then allow these two compartments to communicate and the inflammatory process to spread. We would like to thank Vasconcelos-Santos et al. for the interest in our work.