Prevention of metastasis of intraocular melanoma in mice treated with difluoromethylornithine

The antimetastatic potential of a novel chemotherapeutic agent, alpha-difluoromethylornithine (DFMO), was evaluated in a murine model of intraocular melanoma. In vivo studies demonstrated that DFMO retarded the growth and spontaneous metastasis of murine intraocular melanomas. Further studies indicated that oral DFMO also exercised antimetastatic effects against the blood-borne stage of melanoma metastases. In vitro studies revealed that DFMO exerted impressive antiproliferative effects on three murine melanoma cell lines, four human cutaneous melanoma cell lines, one human uveal melanoma cell line, and one conjunctival melanoma cell line. DFMO inhibited in vitro DNA synthesis in human cutaneous melanoma cell lines by 84%–98% and that in two human ocular melanoma cell cultures by 62% and 86%, respectively. DFMO possesses several characteristics that render it an attractive chemotherapeutic agent for potential use in the management of uveal melanoma. These include its antiproliferative effect against a wide range of murine and human melanomas, its extremely low toxicity, and its ease of administration. Offprint requests to: J. Niederkorn     

Uveal melanoma: epidemiologic aspects

Melanomas of the ocular and adnexal structures comprise approximately 5% of all melanomas. The majority (85%) of ocular melanomas are uveal in origin; primary conjunctival and orbital melanomas are rare. The diagnosis of uveal melanoma is made by clinical examination including indirect ophthalmoscopy and by ancillary studies such as fluorescein angiography and ultrasonography. Metastases to the liver develop within 15 years after the initial diagnosis and treatment in approximately 50% of patients with posterior uveal melanoma; however, clinically evident metastatic disease at the time of initial presentation is uncommon, indicating that there is early subclinical metastasis in most cases.     

BRAF mutations in conjunctival melanoma

PURPOSE: An activating mutation in exon 15 of the BRAF gene has been found in a high proportion of cutaneous melanomas and cutaneous nevi but not in uveal melanoma. Conjunctival melanoma shows greater clinical similarity to cutaneous melanoma than does uveal melanoma. The purpose of this study was to determine whether the T1799A BRAF mutation found in cutaneous melanoma is also present in conjunctival melanoma. METHODS: DNA was extracted from paraffin sections obtained from glutaraldehyde or formalin-fixed, paraffin-embedded conjunctival melanomas. Forty-two specimens were identified from 25 patients. Seminested PCR was used to amplify exon 15 of the BRAF gene, and the resultant PCR product was purified and directly sequenced. Sequences from conjunctival melanomas were compared with the wild-type sequence of the BRAF gene. The presence or absence of the BRAF mutation was compared with the clinicopathological features. RESULTS: The T1799A (V600E) mutation was detected by sequencing in melanomas from 5 of 22 patients as well as in the positive control, a cutaneous melanoma cell line. In this small series, no statistically significant associations between the presence of the BRAF mutation and clinicopathological characteristics were detected, although tumors with this mutation tended to have a larger diameter and greater depth of invasion and to contain epithelioid cells. CONCLUSIONS: Others have demonstrated a BRAF T1799A-activating mutation in cutaneous but not uveal melanoma. In this study, this BRAF mutation was demonstrated in some conjunctival melanoma tissue samples, suggesting that some conjunctival melanomas may share biological features in common with cutaneous melanoma.     

Iris melanoma. Nevus or malignancy?

Although iris melanomas have an excellent prognosis when diagnosed and treated early, they should not be considered benign lesions. The authors report the orbital recurrence of a melanoma in a patient whose eye had been enucleated 30 years earlier because of an iris melanoma. The clinical, epidemiological and pathological characteristics of iris melanomas are summarized and compared to those of other uveal melanomas. The similarities suggest that iris melanomas are not by nature more benign than other uveal melanomas and that their better prognosis is due to the earlier detection allowed by their more obvious location.     

Ocular and oculodermal melanocytosis associated with uveal melanoma

Fifteen patients with ocular or oculodermal melanocytosis were found after reviewing 1210 cases of histologically proven uveal melanomas. The melanoma in each of these patients developed in the eye affected with ocular or oculodermal melanocytosis and not in the unaffected eye. In the one case of bilateral involvement with oculodermal melanocytosis, the patient developed the melanoma in the eye more affected with melanocytosis. In the only case of partial ocular melanocytosis, the melanoma developed in a sector of the eye affected with melanocytosis. A comparison of the prevalence of ocular or oculodermal melanocytosis in patients with uveal melanoma with the prevalence of ocular or oculodermal melanocytosis in the general population, implies that there is an increased incidence of uveal melanomas in patients with ocular or oculodermal melanocytosis.     

Treatment of metastatic uveal melanoma: Review and recommendations

This article reviews the published clinical responses of metastatic uveal melanoma and metastatic cutaneous melanoma with visceral involvement to current therapeutic protocols. Despite isolated patient responses to systemic treatment, no effective treatment currently exists for metastatic uveal melanoma. However, several new approaches involving interferons and interleukin and combination chemotherapy have shown some activity against metastatic cutaneous melanoma. The effectiveness against metastatic uveal melanomas has not been determined. A new approach to intrahepatic administration of chemotherapy also warrants further evaluation because of the high incidence of hepatic involvement with metastatic uveal melanoma. When an effective systemic treatment is found, early administration as an adjuvant to primary treatment may provide the best strategy for control of systemic spread.     

Congenital uveal malignant melanoma: a case report

CASE REPORT: We present a case of congenital choroidal mass in a male infant with multiple cutaneous pigmented lesions. Enucleation performed in the first weeks of life confirmed the diagnosis of diffuse uveal malignant melanoma with extraocular extension. The patient was also treated with 5 cycles of chemotherapy. He subsequently developed cutaneous and ocular pigmented lesions, including 2 choroidal nevi located within the posterior pole and a benign conjunctival lesion in the opposite eye, in addition to malignant melanoma of the skin. COMMENTS: At 10 years follow-up, the child is clinically well with no evidence of further malignancy. We believe this represents the fourth case ever reported in the literature and the longest follow-up of a congenital malignant melanoma originating within the eye.     

Multiplex fluorescence in situ hybridization identifies novel rearrangements of chromosomes 6, 15, and 18 in primary uveal melanoma

Uveal melanomas are the commonest ocular tumour of adults and are characterized by reproducible alterations of chromosomes 1, 3, 6 and 8. These alterations are of prognostic relevance and have also be shown to correlate to high risk and low risk metastatic categories of uveal melanoma as defined by micro-array analysis. It is, however, possible that a catalogue of relevant genetic alterations, involving gene rearrangement rather than amplification, have as yet eluded identification. To address this point we examined 14 primary uveal melanomas, using 24 colour multiplex fluorescence in situ hybridization (M-FISH). All tumours were karyotyped following G-Banding, and M-FISH was performed to confirm and clarify the identity of abnormal chromosomes. M-FISH data were obtained from all tumours and was able to establish the nature of most abnormalities not fully characterized by cytogenetics. Abnormalities of chromosome 6 were far more frequent than previously indicated, in approximately 70% of cases, indicating they have been substantially underrepresented in past studies of uveal melanoma. Spindle melanomas were found to have novel rearrangements affecting in particular chromosomes 6, 15 and 18, suggesting that juxtaposition of genes through translocational events may play a role in the development of some uveal melanomas. In conclusion, this study is the largest of primary uveal melanoma analysed by M-FISH and indicates that alterations of chromosome 6 have previously been underestimated. Furthermore spindle melanomas are prone to rearrangements affecting chromosomes 6, 15 and 18, which may relate to early changes in uveal melanoma development or associate with those melanomas of a more differentiated status.     

Ocular melanoma

Ocular melanomas comprise uveal and conjunctival sub-types, which are very different from each other. A large majority of uveal melanomas involve the choroid, with less than 10% being confined to the ciliary body and iris. They tend to metastasize haematogenously, almost always involving the liver. Therapeutic methods include various forms of radiotherapy, surgical resection and phototherapy, which are often used in combination. Conjunctival melanomas show many similarities to their cutaneous counterparts, often metastasizing by lymphatic spread. Treatment consists of excision of invasive melanoma with adjunctive radiotherapy and/or cryotherapy and topical chemotherapy for intra-epithelial disease. The management of patients with ocular melanomas demands a good understanding of the pathology of these tumours. Pathological examination of the tumour indicates the prognosis and hence the need for further investigation and treatment. The scope of the pathologist is enhanced thanks to advances in molecular biology.     

Ocular melanoma: epidemiology, clinical presentation and relationship with dysplastic nevi

PURPOSE: Ocular melanoma is a rare entity compared to cutaneous malignant melanoma. We examined the frequency of the tumor in a defined geographic region, its clinical presentation and its relationship with dysplastic nevi in 136 patients. METHODS: 136 patients (64 men and 72 women; mean age 61.7 years, range 20-92 years) with ocular melanoma were treated at the University Hospital of Graz between June 1996 and December 2001. 129 had primary uveal melanoma in one eye (117 choroidal melanomas, 11 melanomas of the ciliary body and 1 of the iris), 2 patients had uveal melanoma in both eyes, 4 patients had conjunctival melanoma and 1 patient had a melanoma of the lacrimal sac. Epidemiology, history, potential risk factors, clinical presentation and relationship with dysplastic (= atypical) nevi were documented. RESULTS: 48 patients (35.3%) showed more than five dysplastic nevi, compared to only 1.2% in the general population (chi(2) test: p < 0.001). 5 (3.7%) had additional cutaneous melanoma and 7 (5.1%) had a family history of melanoma. The lifelong risk for the occurrence of an additional primary cutaneous melanoma was 2.9%, which is significantly higher than the usual estimate of 1% for the general population. CONCLUSIONS: Patients with primary ocular melanoma have an increased risk to develop cutaneous melanoma and should therefore be examined regularly by dermatologists.     

Uveal Malignant Melanoma Associated with Ocular and Oculodermal Melanocytosis

Seventeen patients with ocular or oculodermal melanocytosis were identified among 1,250 Caucasian patients with uveal malignant melanoma. The uveal melanomas in these seventeen patients were similar in size, cell type, and tendency to metastasize to those occurring in reported populations without ocular or oculodermal melanocytosis. Clinical and histopathologic study of these 17 cases indicated that all of the affected eyes had episcleral and choroidal melanocytosis and that other ocular and periocular tissues (sclera, iris, conjunctiva, angle structures, and optic disc) were involved less commonly. The uveal malignant melanoma that was present in each of these cases involved the eye with melanocytosis. Furthermore, the melanoma arose from the zone of uveal melanocytosis in every eye with sectoral involvement. Statistical analysis of these data supports the contention that uveal malignant melanoma has a higher incidence in white persons with ocular or oculodermal melanocytosis than in those without these conditions.     

Immunophenotypic markers to differentiate between benign and malignant melanocytic lesions

BACKGROUND/AIMS: The authors investigated the expression of S100A1, S100A6, S100B, MelanA, and CEA in conjunctival naevi, primary acquired melanosis (PAM), conjunctival melanoma, and uveal melanoma in order to assess their potential usefulness in the pathological differential diagnosis of these entities. METHODS: Paraffin embedded sections of 18 conjunctival naevi, 14 PAM, 16 conjunctival melanomas, and 20 uveal melanomas were immunostained for S100A1, S100A6, S100B, MelanA, and CEA, and expression was scored semiquantitatively. RESULTS: Expression of S100A1 differed significantly between conjunctival naevi and conjunctival melanoma, with percentages of positive cells of 30.6% and 71.4%, respectively. Conjunctival melanomas had high average scores for S100A1 and S100B (71.4%, 62.9%, respectively), while uveal melanomas also had high S100A1 but low S100B scores (88.5%, 18.5%, respectively). MelanA was highly variable; naevi and uveal melanoma had higher average scores than conjunctival melanoma. CEA was hardly detectable in all four groups. CONCLUSION: S100A1 seems to be a possible candidate to differentiate conjunctival naevi from conjunctival melanoma. S100B seems to differentiate between uveal melanoma and conjunctival melanoma. However, the study size was small and therefore the data have to be confirmed by others.     

Cripto-1 expression in uveal melanoma: an immunohistochemical study

Human Cripto, the founder member of the epidermal growth factor-Cripto-FRL1-Cryptic (EGF-CFC) family, plays an important role during early embryonic development and in particular in carcinogenesis and the development of cancer metastases. Cripto-1 is over-expressed in most cancers, but is absent or only weakly expressed in normal cells. For this reason, Cripto-1 could be of potential value in the targeted treatment. There is no information on the expression of Cripto-1 in human uveal melanoma. Cripto-1 reactivity was evaluated by immunohistochemistry on 36 archival uveal melanomas using the polyclonal antibody to Cripto-1. The tumors were divided in to 2 groups. There were 18 uveal melanomas with no intrascleral or extrascleral extension and 18 uveal melanomas with intrascleral/extrascleral extension/liver metastasis. Cripto-1 reactivity was correlated with tumor aggressiveness and cell type. Furthermore, we studied the immunolocalization of Cripto-1 in 4 uveal melanoma cell lines OCM-1, OCM-8, and 92-1, and OMM-1 and in 2 primary uveal melanocyte cultures. Cripto-1 was expressed in both the non-invasive and aggressive uveal melanomas. Cripto-1 was positive in the 4 uveal melanoma cell lines and absent in the primary uveal melanocyte cultures. Retinal tissue did not express Cripto-1. The results suggest that Cripto-1 is expressed in uveal melanoma, negative in the non-neoplastic ocular tissue and point to its use as a target for therapy.     

Lack of BRAF mutation in primary uveal melanoma

PURPOSE: BRAF T1796A activating mutations have been found in a high proportion of cutaneous melanomas, cutaneous nevi, and papillary thyroid carcinoma and in a small fraction of other cancers. This study was designed to investigate the incidence of BRAF T1796A mutation in uveal melanoma. METHODS: Twenty-nine formalin-fixed, paraffin-embedded posterior uveal melanomas were included in the study. DNA was extracted from the paraffin sections followed by PCR amplification of exon 15 and detection of the common BRAF missense mutation (T-->A transversion at nucleotide 1796) using restriction enzyme analysis. RESULTS: Although positive cutaneous melanoma control cell lines harbored the T1796A BRAF mutation, none of the 29 uveal melanomas harbored the mutation. CONCLUSIONS: These data suggest that BRAF T1796A activating mutation is not common in primary uveal melanoma. These findings are in accord with known differences in tumorigenesis between uveal and cutaneous melanomas.     

The Differential Diagnosis of Posterior Uveal Melanoma

Two large studies from the Armed Forces Institute of Pathology (AFIP) have listed the various lesions which may clinically resemble malignant melanomas of the posterior uvea (pseudomelanomas). The studies from the AFIP were based upon histologic examination of eyes which were enucleated. The present study reports on 400 consecutive patients who were referred to an ocular oncology center with the diagnosis of posterior uveal melanoma but who proved, by clinical evaluation, rather than by enucleation, to have a pseudomelanoma. Although about 40 different conditions were found to simulate melanoma, the more commonly encountered ones included suspicious choroidal nevus (26.5%), disciform degeneration (12.5%), peripheral disciform degeneration (11%), congenital hypertrophy of the retinal pigment epithelium (9.5%), and choroidal, hemangioma (8%). The authors believe that this series provides the clinician with a differential diagnosis for posterior uveal melanomas which accurately reflects the clinical problem confronting ophthalmologists today.     

Lack of lymphangiogenesis despite coexpression of VEGF-C and its receptor Flt-4 in uveal melanoma

PURPOSE: Because lymphatic vessels are absent from the normal eye and because uveal melanomas are presumed to spread by a hematogenous route in the absence of tumor exposure to conjunctival lymphatics, this study was undertaken to investigate the presence of lymphatic vessels in primary uveal melanomas. METHODS: The presence of lymphatics in 2 control eyes and in 33 primary uveal, 10 primary cutaneous, and 3 metastatic cutaneous melanomas was evaluated by using a double-immunostaining protocol that differentially highlights blood and lymphatic vasculature. In addition, 14 uveal melanomas were immunostained for the lymphatic growth factor vascular endothelial growth factor (VEGF)-C (with anti-VEGF-C polyclonal antibodies [pAbs]), its receptors Flt-4 (with monoclonal antibody [mAb] 9D9) and KDR (with anti-KDR mAb [Clone KDR-2]), and the hemangiogenic factor VEGF-A (with anti-VEGF pAbs). RESULTS: Lymphatics were not detected in normal eyes or in uveal melanoma. As a consequence, signs of lymphangiogenesis were not present. There was coexpression of VEGF-C with Flt-4 and KDR in 6 (43%) of the 14 melanomas. Staining for VEGF-A was completely negative in 25 uveal melanomas analyzed. CONCLUSIONS: The strictly hematogenous metastasis of primary uveal melanomas is explained by the absence of lymphatics in and around the tumor. The current data suggest that, in the presence of endothelial Flt-4, VEGF-C expression is not sufficient to induce lymphangiogenesis from preexisting blood vessels in human cancer.     

Assessment of immunological techniques in the diagnosis and prognosis of ocular malignant melanoma.

Tests of cell mediated immunity (one and two stage leucocyte migration inhibition assays) and humoural immunity (membrane immunofluorescence and serum effects on leucocyte migration) were done with leucocytes and sera from 36 patients with uveal melanoma, five with conjunctival melanoma, 21 with non-malignant ocular disease, and 189 with cutaneous melanoma. Cell mediated reactivity with melanoma extracts and serum reactivity with cultured melanoma cells were significantly more frequent in the melanoma patients, but control donor reactivity was also relatively high. Maximum reactivity was found with cells or serum from those patients in whom, on pathological examination, the intraocular melanoma had penetrated the sclera and in patients with conjunctival melanoma. Maximum separation of melanoma patients from control donors was achieved by consideration of the results of several tests done simultaneously. These immunopathological studies were made during the period from 1972 to 1978. At follow-up in 1983 four of the five patients suffering from conjunctival melanoma had died from metastases, and 10 of the 36 with uveal melanoma had died from metastatic disease. The immunological reactions, while of some value in separating melanoma patients from those without melanoma, did not predict whether a particular patient with uveal melanoma would die of metastatic disease or would survive.     

Multicentric recurrent uveal melanoma

Uveal melanoma is a rare malignancy originating from melanocytes within the uveal tract of the eye. True multifocal uveal melanomas (>2melanomas in 1 eye) occurring in the same eye are very rare. We report a clinically and histologically well-documented case of a patient who presented with 3 uveal melanoma lesions in the same eye over a span of 2.5 years. The eye had to be enucleated finally and diagnosis confirmed histologically. This case report highlights the need for a close follow-up, even after successful treatment of the presenting lesion in uveal melanomas.     

Proton beam radiotherapy of uveal melanoma

Proton beam radiotherapy of uveal melanoma can be administered as primary treatment, as salvage therapy for recurrent tumor, and as neoadjuvant therapy prior to surgical resection. The physical properties of proton beams make it possible to deliver high-doses of radiation to the tumor with relative sparing of adjacent tissues. This form of therapy is effective for a wider range of uveal melanoma than any other modality, providing exceptionally-high rates of local tumor control. This is particularly the case with diffuse iris melanomas, many of which are unresectable. The chances of survival, ocular conservation, visual preservation and avoidance of iatrogenic morbidity depend greatly on the tumor size, location and extent. When treating any side-effects and/or complications, it is helpful to consider whether these are the result of collateral damage or persistence of the irradiated tumor (‘toxic tumor syndrome’).     

葡萄膜与结膜色素性肿瘤核仁组成区银染定量研究

目的：评价银染核仁组成区(AgNORs)和计算机图像分析技术在结膜与葡萄膜色素性肿瘤良恶性鉴别诊断或冒后评估上的价值． 方法：应用AgNORs和计算机图像分析技术对44例葡萄膜恶性黑色素瘤、10例结膜色素痣及10例结膜恶性黑色索瘤进行检测。 结果：结膜恶性黑色素瘤较色素痣AeNORs面积显著增加(P<0.05)；葡萄膜恶性黑色索瘤AgNORs面积则按梭形细胞型、混合细胞型及上皮样细胞型顺序增加(P<0.05). 结论：AeNORs技术可能有助于结膜黑色素瘤良恶性的鉴别诊断，井可作为葡萄膜恶性黑色索瘤预后评价的参数之一。 （中华眼底病杂志，1995，11：181-184）