An Xp22 microdeletion associated with ocular albinism and ichthyosis: approximation of breakpoints and estimation of deletion size by using cloned DNA probes and flow cytometry.

Ocular albinism of the Nettleship-Falls type (OA1) and X-linked ichthyosis (XI) due to steroid sulfatase (STS) deficiency are cosegregating in three cytogenetically normal half-brothers. The mother has patchy fundal hypopigmentation consistent with random X inactivation in an OA1 carrier. Additional phenotypic abnormalities that have been observed in other STS "deletion syndromes" are not present in this family. STS is entirely deleted on Southern blot in the affected males, but the loci MIC2X, DXS31, DXS143, DXS85, DXS43, DXS9, and DXS41 are not deleted. At least part of DXS278 is retained. Flow cytometric analysis of cultured lymphoblasts from one of the XI/OA1 males and his mother detected a deletion of about 3.5 million bp or about 2% of the X chromosome. Southern blot and RFLP analysis in the XI/OA1 family support the order tel-[STS-OA1-DXS278]-DXS9-DXS41-cen. An unrelated patient with the karyotype 46,X,t(X;Y) (p22;q11) retains the DXS143 locus on the derivative X chromosome but loses DXS278, suggesting that DXS278 is the more distal locus and is close to an XI/OA1 deletion boundary. If a contiguous gene deletion is responsible for the observed XI/OA1 phenotype, it localizes OA1 to the Xp22.3 region.

Endogenous Nocardia asteroides subretinal abscess diagnosed by transvitreal fine-needle aspiration biopsy.

The authors report a case of an endogenous Nocardia asteroides subretinal abscess in an immunosuppressed cardiac transplant recipient. On clinical grounds, the metastatic subretinal abscess was initially thought to be a fungal, atypical bacterial, or viral lesion. Transvitreal fine-needle aspiration biopsy of the lesion yielded a sufficient specimen for immediate preliminary identification of the microorganism and permitted prompt initiation of an appropriate antibiotic regimen. The definitive diagnosis was based on culture of the organism from the needle aspirate.

A clinically useful method for combining gross and microscopic measurements to select high-risk patients after enucleation for ciliochoroidal melanoma.

An objective and reproducible method was devised for estimating the malignant potential of ciliochoroidal melanomas after enucleation. This method requires only a single, routine microslide from which nucleolar area and largest tumor dimension are measured. Previous studies have shown these measurements to be reproducible and highly correlated with mortality. To demonstrate a practical method for clinical application of these measurements, a Cox statistical model was derived from 200 cases supplied by the Armed Forces Institute of Pathology. The resulting model, when applied to 340 cases with known outcome from two independent laboratories, allowed subdivision of patients into groups that suffered a six-fold difference in mortality. These results suggest that a central registry, by applying this method to histologic slides from around the world, could provide information useful for the clinical management of patients enucleated for ciliochoroidal melanoma.

Comparison of direct and microslide pathology measurements of uveal melanomas.

Many investigators have shown that large cilio-choroidal melanomas are more likely to be associated with an unfavorable outcome than small tumors by using data retrieved and measured from pathology files. In the past, the measurement of largest tumor dimension (LTD) may not have been recorded at the time of the gross examination, because the significance of this observation was not appreciated. If this information is not available, authors can eliminate cases from their studies, take all their measurements directly from glass microslides, or combine clinical estimates of tumor size for some cases with gross measurements for others. To date, there has been no formal study to compare the measurement of tumor dimensions from glass microslides with measurements made at the time of gross examination by the pathologist. This study of 112 cilio-choroidal melanomas reveals that measurements of the LTD made from the glass microslide correlate with direct measurements taken from the cut surface of the globe at the time of sectioning. Additionally, measurements of the LTD from the glass microslide are at least as effective in predicting patient outcome as direct measurements. These findings suggest that measurements of the LTD from the glass microslide provide as much prognostic information as direct measurements if it is known that the eye was cut to obtain representative sections of the tumor.

Objective assessment of the malignant potential of intraocular melanomas with standard microslides stained with hematoxylin-eosin.

A method for extracting prognostic information from the cytologic details of intraocular melanomas was developed. With computer assistance, a technician measures the nucleolar area of 200 tumor cells randomly selected from a standard paraffin-embedded microsection stained with hematoxylin-eosin, a procedure that requires approximately 40 minutes with an apparatus that costs less than +30,000. Standard deviation of nucleolar area (SDNA), computed from these measurements, provides an objective assessment of nucleolar pleomorphism. Previous studies showed that second measurements of the same microsection or of the same tumor at different levels yield SDNA values that closely approximate the original measurements. The application of this method to 540 cases from three independent laboratories yielded a correlation of SDNA with death from tumor that was high (P much less than 0.001) and consistent among cases from all three sources. Thus, SDNA provides a clinically useful cytologic measure of the malignancy of intraocular melanomas and may ultimately prove valuable in the assessment of other types of tumors.

Metastatic uveal melanoma. Hepatic metastasis identified by hybridoma-secreted monoclonal antibody MAb8-1H.

Monoclonal antibody MAb8-1H, which defines an ocular melanoma-associated antigen retained in fixed tissue, was used to demonstrate metastatic melanoma cells in liver biopsy specimens from five patients with primary choroidal melanoma. In all cases, the monoclonal antibody bound to tumor cells and not to normal hepatocytes. In one case, a well-delineated focus of tumor cells bound to MAb8-1H; in two cases, MAb8-1H appeared to delineate individual tumor cells that were difficult to categorize by conventional staining techniques. The liver biopsy specimens were almost completely replaced by tumor cells in the remaining two cases. This monoclonal antibody may be applicable to the diagnosis of metastatic uveal melanoma and to delineate micrometastasis.

S-antigen in the developing retina and pineal gland: a monoclonal antibody study.

Spleen cells of BALB/c mice, previously immunized with bovine retinal S-antigen, were fused with Sp2/0-Ag14 mouse myeloma cells. Two monoclonal antibodies (MAbs) MAbA9-C6 (IgG2a isotype) and MAbA1-G5 (IgG1 isotype) were selected on the basis of reactivity in an ELISA and immunofluorescent assay. In radioimmunoassay MAbA9-C6 and MAbA1-G5 do not compete and appear to define unrelated epitopes of S-antigen. Both MAbs reacted in the ELISA assay, whereas only MAbA9-C6 bound to S-antigen in fixed tissue sections. Because MAbA9-C6 was useful for immunocytochemistry, it was studied in more detail. MAbA9-C6 bound to all vertebrate retinas tested including human, bovine, guinea pig, and mice. The immunoreactivity of MAbA9-C6 also was studied in the developing rat retina and pineal gland. In the morphologically undifferentiated retina, assessed by conventional light microscopy, there was an incomplete separation of the outer neuroblastic cells. However, in the same retina a distinct zone, corresponding to S-antigen immunoreactivity, was present indicating antigenic differentiation with regard to S-antigen at this stage of retinal development. In the pineal gland, S-antigen immunoreactivity was first observed in the three day old rat and at all stages examined thereafter. The usefulness of these two MAbs in the study of the embryologic development of the retina and of the antigenic epitopes of S-antigen is discussed.