Transscleral visible/near-infrared spectroscopy for quantitative assessment of haemoglobin in experimental choroidal tumours

PURPOSE

To study the feasibility of using transscleral visible/near-infrared spectroscopy (Vis/NIRS) to estimate the content of haemoglobin in choroidal tumour phantoms of ex vivo porcine eyes.

METHODS

Thirty enucleated porcine eyes were prepared with a tumour phantom made by injecting a suspension of gelatine, titanium dioxide and human blood into the suprachoroidal space. The blood concentrations used were 2.5%, 25% and 50%, with 10 eyes in each group. Alternating Vis/NIRS measurements were taken over the phantom inclusion and on the opposite (normal) side of each eye. For statistical analysis, a genetic algorithm was utilized to suppress insignificant wavelengths in the spectra. The processed spectra were then used to build a regression model based on partial least squares regression and evaluated by twofold cross-validation.

RESULTS

Ultrasonography revealed that all phantoms were localized within the suprachoroidal space with no penetration through the retina. The largest mean diameters of the phantoms with 2.5%, 25% and 50% blood were 15.5, 15.2 and 15.7 mm, respectively (p > 0.05). The largest mean thicknesses were 4.5, 4.5 and 4.8 mm, respectively (p > 0.05). Statistical analysis of the spectral data showed that it was possible to correctly discriminate between the normal side and the tumour phantom side of the eyes in 99.88% of cases. The phantoms could be correctly classified according to their blood concentrations in 99.42% of cases.

CONCLUSIONS

This study demonstrates that transscleral Vis/NIRS is a feasible and accurate method for the detection of choroidal tumours and to assess the haemoglobin content in such lesions.

Choroidal metastasis of follicular thyroid adenocarcinoma diagnosed by 25-gauge transretinal biopsy

We report a case of a patient with previously treated follicular thyroid carcinoma who presented with a symptomatic amelanotic choroidal mass with low internal reflectivity and a metastatic lytic skull lesion. A 25-gauge vitrector was used to perform transretinal choroidal biopsy (TRCB), confirming the diagnosis of metastatic follicular thyroid carcinoma.

Bilateral choroidal metastases presenting as acute glaucoma crisis

We report a case of bilateral choroidal metastasis presenting with acute unilateral glaucoma. Primary tumor was found in the lung and choroidal masses in both eyes. Anterior segment neovascularization causing intraocular pressure elevation was the only presenting sign of metastatic choroidal tumor. A painful and hypertensive eye could be symptoms of choroidal metastasis even if no systemic malignancy is encountered.

Red lesions of the iris, choroid, and skin secondary to metastatic carcinoma of the thyroid: a review

An 83-year-old man was seen with a history of bilateral progressive loss of vision of 1 month's duration. On examination, there was a reddish, nodular lesion adjacent to the right side of the nose. Slit-lamp examination revealed a reddish iris mass in the left eye. Ophthalmoscopic examination revealed two orange choroidal lesions in the right eye and a large subretinal hemorrhage in the posterior pole with a central reddish vascular lesion in the left eye. An excisional biopsy of the skin lesion was performed. A diagnosis of metastatic follicular thyroid carcinoma was made according to the histopathologic findings and immunohistochemistry. The patient had no known history of thyroid malignancy and a metastatic survey revealed widespread metastasis. The patient had a total thyroidectomy followed by two series of radioactive iodine ablation. The iris lesion completely resolved and the choroidal lesions in the right eye showed partial regression during the follow-up period. Ocular and skin metastasis secondary to thyroid carcinoma is uncommon. In a review of English literature we found reports of 12 clinically well-documented cases of choroidal metastasis and two cases of iris metastasis. Our case and review of the previous cases reveal that reddish/orange color is a commonly observed feature of the uveal metastasis of thyroid carcinoma. Although ocular and skin metastases from thyroid carcinoma are rare, this possibility should be considered in the differential diagnosis of reddish-colored iris and choroidal masses as well as reddish nodular lesions of the scalp, face, and neck.

[Macroscopic and histological data in the prognosis of malignant choroidal melanoma]

The macroscopic study of choroidal melanoma gives information on tumor extension and tumor size, which help in determining the prognosis and in making the therapeutic choice. Numerous microscopic changes observed in melanomas are also important in the prognosis. However, the number of available histologic specimens has dramatically decreased since the generalized use of conservative radiation treatment. Except in cases of enucleation or choroidectomy, the histologic criteria to establish the prognosis are not available in many cases and cannot be used for wide-range statistical studies.

Cavitary choroidal melanoma

CASE REPORT

We report an unusual case of cavitary choroidal melanoma. The results of ultrasonography, magnetic resonance imaging, computed tomography, and immunohistochemical studies are presented for a 38-year-old woman who developed an amelanotic tumor in the posterior choroid. B-scan ultrasonography disclosed intratumoral cavitations. Systemic and extraocular extension studies were negative. Enucleation was performed and histopathologic examination showed a choroidal melanoma of spindle cell type, with intratumoral cavitations lined by flattened tumor cells.

COMMENTS

The majority of previous reports of intraocular cavitary tumors describe cavitary ciliary body tumors. Uveal melanoma should be included in the differential diagnosis of choroidal cavitary lesions. As far as we know, this is the second documented clinicopathologic correlation of a cavitary choroidal melanoma.

Distinguishing fibrovascular septa from vasculogenic mimicry patterns

CONTEXT

Molecular analyses indicate that periodic acid-Schiff (PAS)-positive (laminin-rich) patterns in melanomas are generated by invasive tumor cells by vasculogenic mimicry. Some observers, however, consider these patterns to be fibrovascular septa, generated by a stromal host response.

OBJECTIVE

To delineate differences between vasculogenic mimicry patterns and fibrovascular septa in primary uveal melanomas.

DESIGN

Frequency distributions, associations with outcome, and thicknesses of trichrome-positive and PAS-positive looping patterns were determined in 234 primary uveal melanomas. Sequential sections of 13 additional primary uveal melanomas that contained PAS-positive/trichrome-negative looping patterns were stained for type I and type IV collagens, laminin, and fibronectin. Real-time quantitative polymerase chain reaction was performed on RNA from cultured uveal melanoma cells for the expression of COL1A1, COL4A2, and fibronectin.

RESULTS

Trichrome-positive loops were encountered less frequently than PAS-positive loops (10% vs 56%, respectively). Death from metastatic melanoma was strongly associated with PAS-positive (P < .001) but not with trichrome-positive (P = .57) loops. Trichrome-positive loops were significantly thicker than PAS-positive loops (P < .001). The PAS-positive patterns stained positive for laminin, type I and type IV collagens, and fibronectin. Type I collagen was detected within melanoma cells and focally within some PAS-positive patterns. Real-time quantitative polymerase chain reaction revealed 3-fold, 25-fold, and 97-fold increases, respectively, in expression of COL4A2, fibronectin, and COL1A1 by invasive pattern-forming primary melanoma cells compared with poorly invasive non-pattern-forming cells.

CONCLUSIONS

Fibrovascular septa are rare and prognostically insignificant in uveal melanomas, whereas vasculogenic mimicry patterns are associated with increased mortality. Type I collagen, seen focally in some vasculogenic mimicry patterns, may be synthesized by tumor cells, independent of a host stromal response.

Analysis of Bcl-2 protein expression in choroidal melanomas

BACKGROUND

Bcl-2 protooncogene alterations are involved in tumorigenesis and may have prognostic ramifications.

AIMS

To investigate normal ocular structures and choroidal melanoma for: (1) Bcl-2 protein expression (semiquantitative staining values: SI, staining intensity; PP, percentage of positive cells; and IRS, immunoreactivity score) and (2) any associations between the staining values and clinicopathological features in these lesions.

MATERIALS/METHODS

Bcl-2 protein expression was analysed in 24 choroidal melanomas using immunoperoxidase staining methods.

RESULTS

Bcl-2 protein expression was seen in corneal epithelium, lens epithelium, the ciliary body, and retinal cells. In these structures, the mean (SEM) values were: 1.1 (0.1), 1.6 (0.3), 1.1 (0.1), and 2.3 (0.3), respectively, for SI; 1.6 (0.2), 1.7 (0.1), 1.7 (0.2), and 1.7 (0.2) for PP, respectively; and 1.9 (0.4), 2.7 (0.5), 1.9 (0.1), and 4.0 (0.8), respectively, for IRS. Based on Bcl-2 immunoreactivity, the lesions were divided into two groups. The first group comprised 12 tumours with Bcl-2 expression. Bcl-2 expression was significantly higher in this group compared with normal ocular structures (1.5 (0.1) v 2.8 (0.2), 1.7 (0.1) v 3.5 (0.1), and 2.6 (0.3) v 9.3 (0.9) for mean (SEM) SI, PP, and IRS scores, respectively; p = 0.00). The second group comprised 12 tumours lacking Bcl-2 protein expression. There was no significant correlation between Bcl-2 protein expression and most of the clinicopathological features of these lesions.

CONCLUSIONS

Bcl-2 protein expression is altered in choroidal melanomas.

Treatment of primary intraocular lymphoma with oral trofosfamide: report of two cases and review of the literature

BACKGROUND

The prognosis of primary intraocular lymphoma (PIOL) is poor. Due to frequent ocular and/or CNS relapses, the optimal treatment for PIOL has not yet been defined. This is the first report of PIOL treatment with trofosfamide.

METHODS

The first patient with a newly diagnosed PIOL was not considered eligible for high-dose methotrexate-based systemic chemotherapy due to comorbidities. The second patient had a primary central nervous system lymphoma, which was resistant to three chemotherapy regimens and responded to whole-brain irradiation. A tumor relapse in the eye was treated with local radiotherapy with initial success; however, the tumor subsequently recurred. The first patient received oral trofosfamide 150 mg daily, the second 400 mg daily (reduced after 5 months of therapy to 300 mg daily) over 5 consecutive days, followed by a 5-day drug-free interval.

RESULTS

In both patients, complete remission was achieved, which lasted for 8+ and 18 months, respectively. Except for a temporary asymptomatic decrease in hemoglobin in the first patient, no toxicity was observed.

CONCLUSIONS

Trofosfamide may offer an alternative treatment option for PIOL with a very favorable side effect profile. The exact role of trofosfamide in the treatment of PIOL remains to be defined.

Laser photocoagulation alters the pattern of staining for neurotrophin-4, GFAP, and CD68 in human retina

AIMS

To investigate the staining pattern of neurotrophin-3 (NT3), neurotrophin-4 (NT4), and brain derived neurotrophic factor (BDNF) as well as glial fibrillary acid protein (GFAP) and CD68 in lasered human retina.

METHODS

Retinal laser photocoagulation was performed on four patients (two males, two females) with choroidal malignant melanoma 1-6 days before enucleation. Three other enucleated eyes with malignant melanoma and three normal cadaveric donor eyes were used as controls. Immunohistochemistry was performed to investigate the pattern of staining of NT3, NT4, BDNF, GFAP, and CD68 in 7 mm sections of fixed specimens.

RESULTS

Expression of NT4 was detected in the inner and outer nuclear layers of all the retinal sections examined but no NT3 and BDNF staining was seen. NT4 staining was found to be less intense in lasered and melanoma controls compared to normal cadaveric donor retinas. There was an upregulation of GFAP expression in both lasered and control eyes with melanoma in comparison with normal controls. CD68 staining was only observed in retinal pigment epithelium and choroid of lasered eyes.

CONCLUSION

NT4 is expressed in inner and outer nuclear layers of normal human retina and its expression is downregulated following laser photocoagulation. This occurs in parallel with an increased expression of GFAP suggesting that reactive changes in Muller cells may be responsible for reduced NT4 staining. Expression of CD68 at the site of laser injury is consistent with a wound healing process as a response to local damage.

Diagnostic intraocular aspiration cytology of choroidal melanoma

Fine-needle aspiration cytology (FNAC) was performed on an intraocular mass in a 32-yr-old Indian woman and a cytologic diagnosis of malignant melanoma was made, supported by immunocytochemistry. The cytologic features included spindle-shaped tumour cells with minimal pleomorphism and the presence of nuclear grooves. No intracellular pigment was identified; however, positivity for HMB-45 allowed a rapid and reliable diagnosis. The utility of FNAC in an atypical presentation of choroidal melanoma is discussed.

Leiomyoma in the posterior choroid: a case report

Smooth muscle tumor of the uveal tract is rare, and mostly located in the cilio-choroidal area. We report a unique case of posterior choroidal leiomyoma in a 27-yr-old man. Ophthalmoscopic examination disclosed an 11 mm-sized mass on the fundus two-disc diameters apart from the optic disc. With a suspicion of amelanotic melanoma, the globe was enucleated. The mass occupied the whole thickness of choroidal stroma beneath the pigmented retinal epithelium and composed of spindle cells arranged in intersecting fascicles. Immunohistochemical studies demonstrated immunoreactivities of the tumor cells for smooth muscle actin, desmin, and vimentin. Ultrastructurally, numerous intracytoplasmic filaments with fusiform focal densities, scattered segmental external laminae, subplasmalemmal densities, and pinocytic vesicles were noted. The leiomyoma in this case had several unusual features in that it was confined to the posterior choroid with no relation to the ciliary body, occupied the whole stroma of the choroid instead of suprauveal location, and occurred in a young male. It is important to include choroidal leiomyoma in the differential diagnosis of choroidal tumors.

Immunophenotypic differences between uveal and cutaneous melanomas

OBJECTIVE

To determine the immunophenotypic differences between uveal and cutaneous melanomas, employing standard melanoma markers as well as p75 neurotrophin receptor (p75NTR) and microphthalmia transcription factor (MITF).

DESIGN

Fifteen uveal melanomas (5 spindle, 5 epithelioid, and 5 mixed uveal subtypes) were immunolabeled with a panel of antibodies that included S100, tyrosinase, melan-A, HMB-45 and HMB-50 combination, MITF, and p75NTR. The results were tabulated on the basis of intensity and pervasiveness of the labeling and compared with a prior study on cutaneous spindle and epithelioid melanomas.

RESULTS

In contrast to its strong labeling of cutaneous melanomas, S100 immunolabeling of uveal melanomas was weak and variable. p75NTR, known to differentiate spindle from epithelioid melanomas of the skin, did not immunolabel uveal melanomas. HMB-45, HMB-50, tyrosinase, melan-A, and MITF immunolabeled all uveal melanomas strongly, irrespective of the histologic subtype, but not cutaneous melanomas. Microphthalmia transcription factor was especially clear in its labeling of uveal melanomas.

CONCLUSIONS

Although cutaneous and uveal melanomas share many molecular markers in common, there are differences between the 2 types of melanoma. First, the level of expression of S100 differs between cutaneous and uveal melanomas. Second, while cutaneous melanomas can be further subdivided into spindle and epithelioid types based on their immunophenotype, the uveal melanomas cannot.

Melanocytoma of the choroid: angiographic and histopathologic findings

A juxtapapillary choroidal melanocytoma that was clinically confused with a choroidal melanoma is described. The clinical examination of a 40-year-old female patient included ultrasonography, fluorescein, and indocyanine green angiography. Histopathologic and immunohistochemical study of the enucleated eye resulted in the identification of a markedly pigmented, 3.8 mm elevated choroidal melanocytic tumor observed nasally to the disk. A-scan ultrasonography showed a high initial spike with a low to medium internal reflectivity with decreasing amplitude. On fluorescein angiography, the tumor was surrounded by a rim of retinal pigment epithelium depigmentation with a well-defined comet-tail. The lesion was hypofluorescent in the early phases of the indocyanine green angiogram, but from the late venous phase appeared ill-defined hyperfluorescence. Histopathologic study revealed a juxtapapillary choroidal melanocytoma The pigmented tumor cells stained positive for HMB45 and vimentin but negative for S100, GFAP, NSE, and MNF116. No tumor cells stained positive for the proliferation marker Ki67. These findings conclude that choroidal melanocytoma may mimick choroidal melanoma. Abnormalities on fluorescein angiography may be a clinical hint to suspect a pigmented tumor different from a choroidal melanoma.

Biopsy in indeterminate intraocular tumors

OBJECTIVE

To describe an intraocular biopsy technique that allows accurate histopathologic diagnosis in cases of clinically unclassifiable uveal tumors.

DESIGN

Retrospective noncomparative consecutive interventional case series.

PARTICIPANTS/METHODS

Intraocular biopsies were performed by a vitreous cutter either by a two-port clear cornea approach in 11 patients with unclassifiable iris tumors or by a three-port pars plana vitrectomy in 23 patients with unclassifiable choroidal tumors. Specimens were formalin fixed and paraffin processed. Hematoxylin-eosin and periodic acid-Schiff stains were performed in all cases, with additional immunohistochemical stains using the alkaline phosphatase, antialkaline phosphatase method in cases that could not be conventionally classified.

MAIN OUTCOME MEASURES

Clinical observation and histopathologic examination of intraocular biopsies.

RESULTS

In 97% of cases (n = 33) a definite diagnosis could be established by the biopsy specimen. A melanoma could be diagnosed in 73% of cases (n = 8) of iris tumors and in 57% of cases (n = 13) of posterior intraocular tumors. Other diagnoses included nevus, metastasis, vasoproliferative tumor, hemorrhage, gliosis, and scleritis. Complications were encountered in four cases: a vitreous hemorrhage occurred twice, an inconclusive biopsy result, and an intraocular tumor spread occurred once, respectively. No increased tumor-related mortality was observed after a mean follow-up of 44 months.

CONCLUSIONS

Intraocular biopsy by a vitreous cutter allows the histopathologic examination of formalin-fixed paraffin-embedded tumor tissue. This increases the diagnostic accuracy, avoiding the risk of extraocular tumor spread seen with transscleral biopsy techniques.

Choroidal metastasis as the initial manifestation of a pigmented neuroendocrine tumor

We report the case of a 77-year-old woman in whom choroidal metastasis was the initial manifestation of a primary neoplasm presumed to be a pigmented pulmonary carcinoid tumor. The tumor initially was misdiagnosed cytologically and pathologically as a choroidal melanoma because it contained intrinsic melanin pigment. Positive immunoreactivity for cytokeratin, synaptophysin, chromogranin, and calcitonin and the presence of dense-core neurosecretory vesicles disclosed by electron microscopy established that the metastasis was a neuroendocrine tumor. Findings from systemic evaluation suggested that the primary tumor was located in the lung. The patient subsequently developed an intradural paraspinal metastasis, which also contained melanin pigment. The latter observation confirmed that the melanin in the uveal metastasis was intrinsic and did not represent secondary phagocytosis by tumor cells. Metastases from pigmented tumors of nonmelanocytic derivation are exceedingly rare but present a major diagnostic challenge to ocular pathologists and cytopathologists if the diagnosis is not suspected. Confirmatory immunohistochemical analysis should be obtained when a pigmented choroidal tumor thought to be a melanoma has atypical features. Arch Ophthalmol. 2000;118:841-845

Choroidal schwannoma: immunohistochemical and electron-microscopic study

Schwannoma (neurilemoma) arising from the ciliary body and choroid is a rare form of intraocular tumor and usually misdiagnosed clinically as amelanotic melanoma. This case report describes a 73-year-old woman who developed a large nonpigmented intraocular tumor of the choroid in the left eye and underwent enucleation with a clinical diagnosis of malignant melanoma. The tumor consisted of spindle-shaped cells with an indefinite cytoplasm and twisted nuclei, which had positive immunoreactivity for S-100 protein, vimentin, glial fibrillary acidic protein and neural cell adhesion molecule. A continuous basal lamina encompassing the tumor cells was demonstrated by immunostaining for laminin and type IV collagen. Ultrastructurally, tumor cells with scant organelles had delicate cytoplasmic processes apposing each other, all indicative of Schwann cell origin. In reexamination of fluorescein angiograms, ultrasonograms and magnetic resonance images, no findings were incompatible with a diagnosis of choroidal melanoma. Histopathological studies showed that the tumor was a schwannoma. At present, we do not have a benchmark for the clinical diagnosis of intraocular schwannoma.

[Biological mineralization in melanoma of the vascular coat of the eye]

Strontium hydroxide Sr(OH)2 has been identified in tumor tissues of patients with melanoma of the vascular coat of the eye and in metastatic tumors to the vascular coat of the eye by x-ray structural analysis. Normal vascular coat of the eye is represented by a mineral natrolite, an adsorbent belonging to zeolites. Presumably, during an oncological process strontium modifies natrolite by changing its adsorption and adhesive properties.

The correlation between cell surface markers and clinical features in choroidal malignant melanomas

PURPOSE

Uveal melanoma continues to present problems when attempting to predict disease progression. This study attempts to identify markers indicative of the biological characteristics of cells isolated from samples of uveal melanoma, including adhesion (ICAM-1), immune reactivity (MHC Class I and II), cell cycle control (c-erbB-2, c-myc) and apoptosis control (bcl-2, p53) using dual parameter (DNA/MoAb) flow cytometry.

METHODS

Sixty-three fresh tissue samples from choroidal melanomas were taken at enucleation. Samples were assayed for DNA content and cell cycle, the above antibodies together with positive (PHM-5) and negative (2 degrees FITC Ab) controls. The clinical parameters sex, age, tumour location, cell type, tumour volume and presence of metastases were compared with the results and analysed with the non-parametric Mann-Whitney U-t-test.

RESULTS

ICAM-1 expression proved to be the most clinically relevant, being present on a higher proportion of cells in tumours > 2000 mm3 (median 38, n = 19) compared with the smaller tumours < 2000 mm3 (median 17, n = 26) (p = 0.0015). Metastatic disease was present in 11 patients and did not correlate with any of the surface markers. C-myc, c-erbB-2 and MHC Class II expression were associated with cell type, all showing greater expression in spindle cell tumours than mixed/epithelial types.

CONCLUSION

These results show flow cytometry as a quick, easy method to provide a 'phenotypic profile' for these tumours, and identifies cell cycle control and adhesion molecule expression as important areas for further investigation. c-erbB-2 and bcl-2 positivity was typically seen on over 60% cells in each sample, indicating two potential targets for therapeutic intervention.

Combination chemotherapy for choroidal melanoma: ex vivo sensitivity to treosulfan with gemcitabine or cytosine arabinoside

Treatment of choroidal melanoma by chemotherapy is usually unsuccessful, with response rates of less than 1% reported for dacarbazine (DTIC)-containing regimens which show 20% or more response rates in skin melanoma. Recently, we reported the activity of several cytotoxic agents against primary choroidal melanoma in an ATP-based tumour chemosensitivity assay (ATP-TCA). In this study, we have used the same method to examine the sensitivity of choroidal melanoma to combinations suggested by our earlier study. Tumour material from 36 enucleated eyes was tested against a battery of single agents and combinations which showed some activity in the previous study. The combination of treosulfan with gemcitabine or cytosine arabinoside showed consistent activity in 70% and 86% of cases, respectively. Paclitaxel was also active, particularly in combination with treosulfan (47%) or mitoxantrone (33%). Addition of paclitaxel to the combination of treosulfan + cytosine analogue added little increased sensitivity. For treosulfan + cytosine arabinoside, further sequence and timing experiments showed that simultaneous administration gave the greatest suppression, with minor loss of inhibition if the cytosine analogue was given 24 h after the treosulfan. Administration of cytosine analogue 24 h before treosulfan produced considerably less inhibition at any concentration. While we have so far been unable to study metastatic tumour from choroidal melanoma patients, the combination of treosulfan with gemcitabine or cytosine arabinoside shows activity ex vivo against primary tumour tissue. Clinical trials are in progress.

Clinicopathologic correlation in a case of metastatic uveal tumor

A clinicopathologic correlation is reported of an ocular metastasis from an unknown primary tumor. The tumor appeared initially confined to the choroid. The diagnosis of metastatic adenocarcinoma was obtained by choroidal biopsy. The metastasis was uncontrollable with teleradiotherapy. Six months later the anterior segment also appeared infiltrated and the eye was enucleated.

Clear cell differentiation in choroidal melanoma. COMS report no. 8. Collaborative Ocular Melanoma Study Group

OBJECTIVE

To describe 2 enucleated eyes of patients enrolled in the Collaborative Ocular Melanoma Study that contained primary choroidal melanoma with clear cell features.

METHODS

During a 9-year period, 1493 eyes enucleated as part of the Collaborative Ocular Melanoma Study routinely processed for histologic examination were evaluated by the pathology review committee (H.E.G, D.M.A, and W.R.G). Two eyes with unusual variants of choroidal melanoma were identified and immunostained for S100 protein and HMB 45. Portions of the tumors were processed for electron microscopic examination.

RESULTS

Results of electron microscopic examination of both tumors displayed malignant melanoma (mixed cell type with many malignant cells with clear cytoplasm). The cytoplasm of the clear cells stained with periodic acid-Schiff and failed to stain when pretreated with diastase. Results of immunohistochemical stains in both tumors were positive for S100 protein and HMB 45 in the tumor cells. Results of electron microscopic examination showed that the cytoplasm of the clear cells contained scattered glycogen granules, premelanosomes, and melanosomes.

CONCLUSION

These cases represent a clear cell variant of malignant melanoma of the choroid. This tumor should not be confused with metastatic clear cell carcinoma to the choroid.

Metastatic choroidal melanoma to the contralateral orbit 40 years after enucleation

Metastatic uveal melanoma to the contralateral orbit is extremely rare, with only eight cases in the literature having been reported. We reviewed the clinical presentation, the histologic findings of the primary and secondary tumors, and the clinical outcome of these cases and studied an additional case of metastatic choroidal melanoma to the contralateral orbit that occurred 40 years after enucleation for the primary tumor. The long interval between recognition of the primary tumor and the appearance of clinically manifest metastatic disease in the contralateral orbit is the longest reported in the literature to date. The histologic features of the tumor cells of the enucleation specimen and those of the orbital metastasis were similar, consisting of spindle-cell type with minimal atypia. Combined use of immuno-phenotyping and electron microscopy substantiated the diagnosis of melanoma.

p53 oncoprotein overexpression in choroidal melanoma

This study immunohistochemically demonstrates p53 oncoprotein overexpression on routinely processed choroidal melanomas by means of four different anti-p53 antibodies after high-temperature antigen retrieval. The results were correlated both with morphologic and clinical parameters. Routinely formalin-fixed and paraffin-embedded tumor tissues from 43 choroidal melanomas were immunohistochemically investigated with four different anti-p53 antibodies directed against four different epitopes (CM-1, DO-7, PAb1801, PAb240) after wet autoclave antigen retrieval. The application of this technique is of outstanding importance for the demonstration of p53 protein on routinely processed tissues. Five patients (11.6%) of 43 showed more than 10% p53-positive tumor cell nuclei, which was regarded as p53 overexpression; these five patients underwent preoperative telecobalt or ruthenium irradiation. An additional 18 patients (41.9%) showed a few positively stained nuclei with at least one of the antibodies applied. p53 expression was more often found in epithelioid cell tumors; there was no statistical correlation between p53 overexpression and the clinical outcome. Our results suggest that p53 oncoprotein overexpression in choroidal melanomas indicates a late event in the progression rather than a crucial step in the development of these tumors. This conclusion is supported by the finding that all tumors with immunohistochemical p53 overexpression underwent preoperative irradiation, which might have caused p53 alteration(s) and thus enabled its immunohistochemical demonstration.

Estrogen and progesterone receptor analysis in ocular melanomas

BACKGROUND

It has been suggested that pregnancy may promote metastases in melanoma and that the contraceptive pill may be an etiologic factor. The purpose of this study is to determine if uveal or conjunctival melanomas express estrogen or progesterone receptors.

METHODS

Twenty-seven choroidal and five conjunctival melanomas were investigated. Immunohistochemistry was performed using the antibodies ER-D5, which recognizes heat-shock protein 27 (formerly called the estrogen receptor-associated cytoplasmic antigen); ER-1D5, which recognizes the estrogen receptor; and PgR, which recognizes the progesterone receptor.

RESULTS

Most of the conjunctival and uveal melanomas stained strongly for heat-shock protein 27 but none of the tumors showed positive nuclear staining for either the estrogen or the progesterone receptor.

CONCLUSIONS

No evidence was found for either estrogen receptor or progesterone receptor expression in choroidal or conjunctival melanomas. Based on the literature, there is little evidence for these hormones having a role in the development or progression of these tumors.

[Lectin histochemistry of choroidal malignant melanoma]

Tumor specimens of malignant choroidal melanoma from a 50 year-old man were studied with reference to labeling with fluorescence-labeled lectins: wheat germ agglutinin (WGA), specific for sialic acid and N-acetylglucosamine, and Ricinus communis agglutinin-1 (RCA-1), specific for galactose. Epithelioid cells occupying the apex and internal portion of a dome-shaped tumor had intense labeling of WGA but little binding to RCA-1. Spindle-shaped cells in the base of the tumor were labeled moderately with WGA and faintly with RCA-1. Neuraminidase treatment of the specimens led to a marked increase in the RCA-1 binding to both epithelioid and spindle-shaped tumor cells. The results suggest association of the malignancy of choroidal melanoma cells with oligosaccharides of cell membrane-bound glycoconjugates.

The clinical status of immunoscintigraphy with monoclonal antibodies in ocular melanoma

A summary is given of data on the clinical experience with the anti-melanoma antibody 225.28S in ophthalmology and the tissue expression of the high molecular weight-melanoma associated antigen in choroidal melanoma. Results are discussed in relation to other detection methods for ocular melanoma currently employed by the ophthalmologist.