Histopathologic characteristics of uveal melanomas in eyes enucleated from the Collaborative Ocular Melanoma Study. COMS report no. 6

Expression and distribution of MMPs and TIMPs in human uveal melanoma

Matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) are involved in tumour invasion, metastasis and angiogenesis, and have been implicated as progression markers in uveal melanoma, although their topographical expression has not been fully described. In this study we compared the distribution and specificity of several classes of MMPs (MMP-1, -2, -9, -19, and MT1-MMP) and physiological MMP inhibitors (TIMP-2 and -3) in different regions of the tumour microenvironment and adjacent choroid in a series of primary uveal melanomas. Paraffin sections of untreated uveal melanomas (n=18, 3/18 spindle; 11/18 mixed, and 4/18 epithelioid) were examined for MMP-1 (collagenase 1), MMP-2 and MMP-9 (gelatinases A and B), MT1-MMP (membrane-type 1-MMP), MMP-19, TIMP-2 and TIMP-3 (tissue inhibitors of MMPs), using indirect peroxidase immunohistochemistry. The distribution and intensity of immunolabelling was graded semi-quantitatively (0-3) by 2 independent observers. Non-parametric analyses were used to test for associations between tumour cell type, and the average grade of MMP or TIMP expression. Immunostaining for MMP-1, -9, -19 and MT1-MMP was > or =Grade 2 in more than 70% of specimens, and a heterogeneous pattern of MMP-1, -9, MT1-MMP and TIMP-3 expression was observed. At the tumour-scleral interface (TSI), melanoma cells had a flattened morphology and a much reduced MMP and TIMP expression, with a high expression in tumour areas adjacent to the TSI. Tumour vasculature and stromal cells strongly expressed MMP-2. We also observed heterogeneous immunostaining of the vasculature by MMP-1, -9, MT1-MMP and TIMP-2 antibodies, and of the extravascular matrix by MMP-9 antibody. The distinct immunostaining patterns observed for MMPs and TIMPs within uveal melanoma are consistent with their involvement in tumour growth and angiogenesis. In particular, the heterogeneous expression within regions of the tumours, and the localized expression in vasculature and stromal cells emphasises the importance of the tumour microenvironment in the pathogenesis of uveal melanoma (and other tumours).

Baseline echographic characteristics of tumors in eyes of patients enrolled in the Collaborative Ocular Melanoma Study: COMS report no. 29

PURPOSE

To report baseline echographic characteristics of tumors in patients enrolled in the Collaborative Ocular Melanoma Study (COMS) randomized trials, to determine how often these characteristics matched prespecified criteria for choroidal melanoma, to explore associations between echographic variables, and to compare specific echographic characteristics with pathologic characteristics of tumors in enucleated eyes.

DESIGN

Retrospective analyses of baseline data from multicenter randomized clinical trials.

PARTICIPANTS

Patients enrolled in the COMS large trial or medium tumor trials (N = 2320).

METHODS

Standardized echography was used to document selected characteristics of tumors at baseline. Criteria were established to assess the consistency of echographic features with the diagnosis of melanoma. For eyes assigned to enucleation, the echographic diagnosis and evaluation for extraocular extension by the Echography Center were compared with gradings made by the Pathology Center and Pathology Review Committee.

MAIN OUTCOME MEASURES

Presence of various echographic and pathologic characteristics.

RESULTS

Two thousand forty-three tumors (88%) exhibited low to medium reflectivity (n = 1409), a mushroom shape (n = 101), or both (n = 533). Tumors with apical height > 10 mm were more likely (P<0.001) to have a mushroom shape and less likely to have a posterior location (P<0.001) than less elevated tumors. One thousand five hundred fifty-nine (99.7%) of 1563 tumors judged by echography to be consistent with the diagnosis of melanoma were confirmed by pathology to be choroidal melanoma. For measurable extrascleral tumors < 1.5 mm in height by pathology, the Echography Center graders judged extrascleral extension as possibly present in only 1 of 16 (6%) tumors, compared with 57% (4/7) of eyes with extrascleral extension measuring > or = 1.5 mm in height.

CONCLUSIONS

Eighty-eight percent of the tumors in the COMS exhibited features characteristic for melanoma: low to medium reflectivity, the classic mushroom shape, or both. Using additional preset criteria, 96% of tumors exhibited baseline echographic characteristics consistent with the diagnosis of melanoma. Echography graders were able to detect extrascleral nodules > or = 1.5 mm in elevation but not minimally elevated extraocular tumor extension. Clinicians and echographers can use these data to improve their understanding of the echographic features of untreated uveal melanomas.

Peripheral subretinal pigment accumulation following transpupillary thermotherapy for choroidal melanoma

Transpupillary thermotherapy (TTT) used as either an adjunct to plaque brachytherapy or a primary treatment for choroidal melanoma can cause several intraocular complications, particularly in the retina. A 61-year-old woman had a macular choroidal melanoma measuring 8 x 7.5 X 3.6 mm and received TTT in three sessions, each 6 months apart. After the second treatment, pigmented material began to accumulate on the peripheral retina with an increasing pace. The tumor gradually regressed for 16 months, followed by a sudden regrowth. Enucleation of the eye revealed that the peripheral subretinal pigmented deposits consisted of pigment-laden macrophages and retinal pigment epithelial cells without viable tumor cells. The rare complication of peripheral subretinal pigment dispersion following TTT should not be alarming, but close monitoring is recommended.

Expression of vascular endothelial growth factor-A, matrix metalloproteinase-9, and extravascular matrix patterns and their correlations with clinicopathologic parameters in posterior uveal melanomas

PURPOSE

To assess extravascular matrix patterns (EMP) and expression of vascular endothelial growth factor-A (VEGF-A) and matrix metalloproteinase-9 (MMP-9) in posterior uveal melanomas and their correlations with histopathologic parameters and metastasis.

METHODS

This study was conducted on 100 consecutive eyes enucleated for posterior uveal melanomas. All tumors were examined by immunohistochemical techniques for VEGF-A and MMP-9 expression, and the presence of EMPs was assessed on routine paraffin sections stained with reticulin. Cell type, tumor localization, degree of pigmentation, necrosis, mitotic index, lymphocytic infiltration, and scleral and optic nerve invasion were analyzed by using light microscopy. No eyes had received prior treatment such as radiotherapy or transpupillary thermotherapy.

RESULTS

Identified histopathologically, cell types were spindle cells in 60% of the cases, mixed cells in 14%, and epithelioid cells in 26% of tumors. Positive reaction for VEGF-A and MMP-9 was present in 84% and 72% of the tumors, respectively. Microvascular loops and/or networks were seen in 34% of the tumors, with the remaining 16% of the tumors displaying an arc pattern, 21% displaying a parallel pattern, and 29% displaying the normal pattern. The relationships between VEGF-A and MMP-9 expression and necrosis, the degree of lymphocyte infiltration, mitotic rate, and the formation of loop and network patterns were found to be statistically significant (P < 0.05). Metastatic disease developed in 14 patients during follow up.

CONCLUSIONS

The incidence of metastatic melanoma increased with the increasing expression of VEGF-A and MMP-9. Our data suggest that increasing VEGF-A and MMP-9 expression and the EMP can be used as independent prognostic factors in the management of posterior uveal melanoma following enucleation.

Choroidal melanoma: natural history and management options

BACKGROUND

Choroidal melanoma is the most common primary malignancy of the eye. Enucleation has been the mainstay of treatment, but new and more effective options have recently been proposed as eye- and vision-sparing alternatives.

METHODS

We reviewed the medical literature for trials and case reports involving the evolution, current uses, and limitations of alternatives to enucleation for treating choroidal melanoma.

RESULTS

Options to treat choroidal melanomas depend on the location and size of the tumor and goals of therapy. Local control with plaque radiotherapy has provided overall survival comparable to enucleation. Transscleral resection may leave behind potentially viable melanoma cells following surgery; adjuvant brachytherapy is recommended to irradiate remaining tumor cells. Elevating tissue temperature potentiates the effect of ionizing radiation, thus reducing the dose of radiation needed to treat uveal melanoma. Transpupillary thermotherapy has been effective only in select circumstances, and long-term results have shown poorer local control rates and similar visual outcomes compared with other conservative treatment methods.

CONCLUSIONS

Treatment therapies for choroidal melanoma warrant further study. Currently, enucleation remains as effective as the eye- and vision-sparing approaches.

[Importance of the length of excised optic nerve in enucleations for uveal melanoma]

The importance of a length of excised optic nerve in eyes enucleated for uveal melanoma isnt finaly discussed. We analyzed 473 eyes enucleated for uveal melanoma between 1995. and 2004. at Institute of opthanlmology in Belgrade, 16 (3,7%) of which extended into the optic nerve or its meningeal sheaths. Peripapillary melanomas and large melanomas in eyes with increased intraocular pressure and poor vision were associated with optic nerve invasion. This tumors, as a rule, require an enucleation as a treatment of choice. Autors suggest that a long piece of optic nerve should be excised when eyes with uveal melanomas are enucleated.

Optic nerve invasion of uveal melanoma

The aim of the study was to identify the histopathological characteristics associated with the invasion of the optic nerve of uveal melanoma and to evaluate the association between invasion of the optic nerve and survival. In order to achieve this, all uveal melanomas with optic nerve invasion in Denmark between 1942 and 2001 were reviewed (n=157). Histopathological characteristics and depth of optic nerve invasion were recorded. The material was compared with a control material from the same period consisting of 85 cases randomly drawn from all choroidal/ciliary body melanomas without optic nerve invasion. Prelaminar/laminar optic nerve invasion was in multivariate analysis associated with focal retinal invasion, neovascularization of the chamber angle, and scleral invasion. Postlaminar invasion was further associated with non-spindle cell type and rupture of the inner limiting membrane of the retina. The optic nerve was invaded in four different ways: 1) by tumor extension from the neuroretina through the lamina cribrosa; 2) by direct extension into the optic nerve head between Bruch's membrane and the border tissue of Elschnig; 3) by direct invasion through the border tissue of Elschnig; and 4) in one case a tumor spread along the inner limiting membrane to the optic nerve through the lamina cribrosa. Invasion of the optic nerve had no impact on all-cause mortality or melanoma-related mortality in multivariate analyses. The majority of melanomas invading the optic nerve are large juxtapapillary tumors invading the optic nerve because of simple proximity to the nerve. A neurotropic subtype invades the optic nerve and retina in a diffuse fashion unrelated to tumor size or location.

Novel low-kVp beamlet system for choroidal melanoma

Background

Treatment of choroidal melanoma with radiation often involves placement of customized brachytherapy eye-plaques. However, the dosimetric properties inherent in source-based radiotherapy preclude facile dose optimization to critical ocular structures. Consequently, we have constructed a novel system for utilizing small beam low-energy radiation delivery, the Beamlet Low-kVp X-ray, or "BLOKX" system. This technique relies on an isocentric rotational approach to deliver dose to target volumes within the eye, while potentially sparing normal structures.

Methods

Monte Carlo N-Particle (MCNP) transport code version 5.0(14) was used to simulate photon interaction with normal and tumor tissues within modeled right eye phantoms. Five modeled dome-shaped tumors with a diameter and apical height of 8 mm and 6 mm, respectively, were simulated distinct positions with respect to the macula iteratively. A single fixed 9 × 9 mm² beamlet, and a comparison COMS protocol plaque containing eight I-125 seeds (apparent activity of 8 mCi) placed on the scleral surface of the eye adjacent to the tumor, were utilized to determine dosimetric parameters at tumor and adjacent tissues. After MCNP simulation, comparison of dose distribution at each of the 5 tumor positions for each modality (BLOKX vs. eye-plaque) was performed.

Results

Tumor-base doses ranged from 87.1–102.8 Gy for the BLOKX procedure, and from 335.3–338.6 Gy for the eye-plaque procedure. A reduction of dose of at least 69% to tumor base was noted when using the BLOKX. The BLOKX technique showed a significant reduction of dose, 89.8%, to the macula compared to the episcleral plaque. A minimum 71.0 % decrease in dose to the optic nerve occurred when the BLOKX was used.

Conclusion

The BLOKX technique allows more favorable dose distribution in comparison to standard COMS brachytherapy, as simulated using a Monte Carlo iterative mathematical modeling. Future series to determine clinical utility of such an approach are warranted.

Necrotic uveal melanoma with orbital inflammation

PURPOSE

Extraocular extension of uveal melanoma can be accompanied by proptosis and signs of orbital inflammation but this clinical presentation is an uncommon feature if the tumor is solely intraocular.

METHODS

Case report.

RESULTS

The authors describe a patient with a medium-sized necrotic uveal melanoma, without extraocular spread, presenting with the clinical picture of orbital cellulitis.

CONCLUSIONS

The ophthalmologist needs to be aware of this uncommon presentation of uveal melanoma, and not assume the presence of proptosis and orbital inflammation as signs of extraocular extension.

Primary transpupillary thermotherapy for 18 small posterior pole uveal melanomas

PURPOSE

To evaluate transpupillary thermotherapy (TTT) for the treatment of small uveal melanomas of the posterior pole.

DESIGN

Prospective, nonrandomized interventional case series.

METHODS

Eighteen patients underwent TTT for small uveal melanomas located in the posterior pole of the eyes. Tumors were between 2.5 and 4 mm in thickness. TTT was performed with a diode laser at 810 nm. Patients had between one and three TTT sessions, with an intensity adapted to the coloration of the fundus impact. Biomicroscopic examination, ultrasonographic measurements, and angiography were performed before and two months, four months, and six months after treatment, then regularly during follow-up.

RESULTS

Eight of the 18 tumors regressed and 10 recurred. The one- and two-year metastasis-free survival rates calculated by the Kaplan-Meier method were, respectively, 61.11% to 44.44% (95% confidence interval). Recurrences were managed with enucleation (three patients), proton beam therapy (six), or additional thermotherapy (one). After treatment, visual acuity was maintained or improved for the eight patients with nonrecurrent tumors. Pathologic analysis of the three enucleated eyes revealed scleral invasion.

CONCLUSIONS

Despite encouraging initial short-term results obtained with TTT for the management of small choroidal melanomas, the occurrence of severe complications, especially recurrences and insufficient local tumor control, should raise concern about indications for primary TTT given as isolated treatment for small melanomas of the posterior pole.

Orthotopic human choroidal melanoma xenografts in nude rats with aggressive and nonaggressive PAS staining patterns

PURPOSE

Choroidal melanoma is the most common primary ocular cancer among the adult population. Patient survival has been linked to the periodic acid-Schiff base (PAS)-positive vascular patterns in the tumors. The presence of PAS-positive loops or cross-linking parallel channels is a marker of an aggressive tumor. The purpose of this study was to develop new xenograft models of human choroidal melanoma that predictably demonstrate the PAS staining patterns associated with nonaggressive and aggressive tumors in humans.

METHODS

Three human choroidal melanoma cell lines (C918, M619, and OCM-1) were used. C918 and M619 are considered aggressive, based on their ability to form PAS-positive channels in vitro. The nonaggressive OCM-1 cells do not form these channels. C918, M619, and OCM-1 spheroids were grown and implanted in the suprachoroidal space of 20, 17, and 16 WAG/RijHs-rnu nude rats, respectively. Tumors were grown for 1 to >4 weeks, and histology was performed to evaluate tumor growth and determine PAS labeling patterns.

RESULTS

Growth of C918, M619, and OCM-1 xenografts were histologically verified in 20/20, 15/17, and 16/16 rats, respectively. PAS staining revealed loops and cross-linking parallel channels, typical of aggressive tumors in patients, in 90% of C918 and 100% of M619 xenografts. Only 4 of 16 OCM-1 xenografts showed PAS-positive loops. The rest showed no PAS staining or only perivascular staining, indicative of nonaggressive tumors.

CONCLUSIONS

It is possible to grow human choroidal melanoma orthotopic xenografts in nude rats that reproduce the PAS staining patterns associated with aggressive and nonaggressive choroidal melanomas in patients.

Transpupillare Thermotherapie (TTT) von Aderhautmelanomen

BACKGROUND

An increasing number of orbital recurrences after TTT have been reported; the aim of our paper was to present our long-term results after a maximum follow-up of 8 years and 2 months.

PATIENTS AND METHOD

Among 18 eyes, 10 tumors were classified as small, and 8 as medium sized (with a maximum prominence of 5.6 mm): 5 melanomas had a juxtapapillary location, 6 a macular (or juxtamacular) location, and 7 were located in the midperiphery of the fundus.

RESULTS

After a median follow-up of 7 years in seven tumors a complete regression (scar formation) could be achieved, and in six a partial regression (with a maximum residual prominence of 2.9 mm) could be seen. In three patients a recurrence was treated either by another TTT or a Ruthenium-106 plaque; in another two recurrences, enucleation had to be performed. In none of the cases has an orbital recurrence occurred so far.

CONCLUSION

To prevent recurrences, adequate technique and appropriate selection of patients are mandatory in our opinion (no tumors higher than 3 mm). The higher the tumor prominence, the greater the chance of recurrences. Amelanotic melanomas and macular melanomas seem to respond poorly to thermotherapy.

Extrascleral extension in association with ciliochoroidal melanoma: ultrasound biomicroscopy with histopathological correlation

CASE REPORT

We present the case of a 71-year-old man with a melanoma arising from the ciliary body and extending into the choroid. Ultrasound biomicroscopy (UBM) revealed connection via an emissary canal to a subconjunctival nodule. Although evaluation for metastasis was negative at the time of diagnosis, multiple hepatic metastatic deposits were found 2 years post-enucleation.

COMMENTS

It is crucial to identify the presence of scleral invasion and extrascleral extension for proper management planning in patients with choroidal melanomas. This case demonstrates that UBM is an accurate and useful tool for characterizing the morphologic pattern of scleral invasion of intraocular tumours.

Choroidal melanoma with massive extrascleral extension in a young black man

The reported incidence of choroidal melanoma is low among the general population and is especially low among blacks. Choroidal melanoma is seen most commonly in whites in the sixth to seventh decades. The tumor is complicated by orbital invasion in only a small percentage of cases. This report describes the case of a 38-year-old black man diagnosed with a choroidal melanoma of the right eye. The tumor exhibited extensive orbital invasion. Primary or metastatic disease elsewhere in the body was ruled out, and the patient underwent an eyelid-sparing orbital exenteration. Histopathologic examination of the orbital specimen confirmed the diagnosis of spindle cell-type choroidal melanoma. Orbital invasion by a primary choroidal melanoma in a black person under the age of 40 is highly unusual. To our knowledge, this represents the youngest reported case of choroidal melanoma with extrascleral extension in a black patient. Ophthalmologists should consider the possibility of this potentially deadly tumor, even in young, black patients.

Ultrasonographic tissue characteristics of mushroom-shaped uveal melanoma

PURPOSE

To evaluate the ultrasonographic tissue characteristics of mushroom-shaped versus dome-shaped uveal melanoma and to compare them with the tumor vasculature.

METHODS

We examined clinically and ultrasonically 18 dome-shaped and 11 mushroom-shaped uveal melanomas (29 consecutive patients; mean age 57 years) and compared their normalized A-scan patterns. Using histological sections from a different set of patients (12 dome- and 17 mushroom-shaped tumors), we calculated the percentage of area covered by blood vessels.

RESULTS

A-scans of dome-shaped tumors presented low homogeneous reflectivity, whereas the heads of mushroom-shaped tumors had high and irregular reflectivity (p < 0.001). The reflectivity of their bases was low and similar to dome-shaped tumors. The blood vessel area in the histological sections was significantly larger in the heads of mushroom-shaped tumors (0.88 +/- 0.14%), compared both to their bases (0.29 i 0.06%) (p < 0.001) and to dome-shaped tumors (0.07 i 0.03%) (p < 0.0001).

CONCLUSIONS

The ultrasonographic pattern suggests vascular congestion in the heads of mushroom-shaped tumors,probably due to strangulated blood vessels in the tumor neck.

Diagnosis and treatment of orbital invasion in uveal melanoma

The presence of extraocular extension of uveal melanoma is a known prognostic factor that significantly affects patient survival and the risk of orbital recurrence. Interest in this uncommon event in patients with uveal melanoma has been renewed owing to recent reports of extraocular growth after conservative treatment. Ultrasonography and magnetic resonance imaging seem to be the most sensitive imaging techniques to detect even small degrees of extraocular extension. However, some cases are identified at surgery during enucleation or brachytherapy. Although there is a lack of consensus as to the optimal therapeutic management of orbital invasion in uveal melanoma, the current treatment options include isolated resection and modified enucleation or exenteration combined with radiotherapy or other forms of adjuvant therapy.

Plaque radiotherapy for choroidal and ciliochoroidal melanomas with limited nodular extrascleral extension

BACKGROUND

Currently available clinical information regarding management of posterior uveal melanomas complicated by nodular extrascleral extension is inadequate to determine the role, if any, for plaque radiotherapy in such patients.

METHODS

The authors performed a retrospective descriptive study of eight patients with a choroidal or ciliochoroidal melanoma complicated by nodular extrascleral extension who were treated by surgical excision of the extrascleral nodule followed immediately by plaque radiotherapy of the intraocular tumour. The calculated volume of the extrascleral nodule was greater than 1 mm3 but less than 1000 mm3 in all cases, and the intraocular tumour was deemed treatable by plaque radiotherapy in all patients.

RESULTS

Four of the eight patients died during available follow-up, three from metastatic melanoma and one from a second cancer. The median length of follow-up for the four surviving patients was 10.1 years. The actuarial 5-year and 10-year all-cause death rates were 37.5% and 53.1% respectively. One of the eight patients experienced local intraocular tumour relapse following plaque therapy and underwent secondary enucleation. None of the patients experienced orbital tumour recurrence or underwent secondary orbital exenteration.

INTERPRETATION

Our results coupled with previously published results from another centre suggest that plaque radiotherapy may be an effective local treatment for selected patients with choroidal or ciliochoroidal melanoma complicated by nodular extrascleral extension. The fact that none of the patients in this series or in the previously reported series experienced orbital recurrence following plaque radiotherapy or required secondary orbital exenteration suggests that plaque therapy may be better than enucleation alone in terms of these end points. These results should not be extrapolated, of course, to patients with massive extrascleral tumour extension or a choroidal or ciliochoroidal melanoma too large for plaque radiotherapy.

Evidence of macrophage and lymphocyte, but not dendritic cell, infiltration in posterior uveal melanomas, whilst cultured uveal melanomas demonstrate pluripotency by expressing CD68 and CD163

Although variation in the level of macrophage infiltration has been reported in uveal melanoma, little is known about the expression of other leucocyte markers. An immuno- histochemistry study of the levels of expression of macrophage and other leucocyte markers, in a series of 10 primary choroidal melanoma biopsies, was undertaken. Biopsies were either fixed immediately in formalin and embedded in paraffin wax or established as short-term cultures. Using single- and double-labelling immunohistochemistry, cultured cells and paraffin sections were analysed for a range of melanoma (HMB45, Melan A, S100 and tyrosinase) and immune cell (CD68, CD163, CD45 and CD1a) markers. All samples expressed at least two known melanoma markers. Infiltrating macrophages were present in the majority of sections. When cultured specimens were studied by double-labelling immunofluorescence, uveal melanoma cells were seen to express macrophage markers or have cross-reactivity with related proteins. Expression of the leucocyte antigen CD45 was observed in three tumours but was not present in any cultured cells, whilst the expression of the dendritic cell marker CD1a was absent from all samples.

Ciliary body melanoma: a special challenge

Although there is little doubt that the delayed recognition of ciliary body melanoma has a bearing on patient management and ultimate survival, the most compelling issues that face the clinician treating this neoplasm relate to the metastatic patterns and mechanisms of the disease. Several aspects of diagnosis and management of this tumour provide a unique challenge to the clinician. Ciliary body melanoma can remain clinically inapparent to the patient as well as to the clinician during its formative period. In management, tumour characteristics, including anterior and posterior margins, are more readily visualized with ultrasound biomicroscopy (UBM) than with other imaging techniques. UBM can provide valuable information when considering intervention, including biopsy, resection or plaque radiotherapy. Management depends on tumour size, intraocular involvement, patient preference and the presence or absence of systemic manifestations.

Uveal melanoma: update and future directions

In this article the author discusses advances in the treatment of ocular melanoma over the past 25 years. However, owing to metastatic disease, patient survival has not improved. Research into molecular and cellular biology and genetic factors is needed to better understand metastasis in order to improve survival.

Microvascular loops and networks in uveal melanoma

Microvascular patterns--three-dimensional architectural arrangements of microvessels and extravascular matrix in uveal melanoma--were discovered when investigators were looking for histopathological features of sufficient size to be imaged clinically. Evidence that these patterns may be formed by tumour cells and that they may be able to conduct plasma and blood as well as discovery of similar elements in other cancers make them of general importance. Of nine different patterns described, closed microvascular loops and networks have been studied most extensively. When cell type, microvascular density and nucleolar size are controlled for, these two patterns independently predict time to metastasis. In addition to visualization in tumour specimens stained with periodic acid-Schiff reagent, they can often be visualized clinically on confocal indocyanine green angiography. The presence of networks is clinically associated with probability of growth of small uveal melanocytic tumours and with the rate of regression of uveal melanoma after brachytherapy. Networks are also associated with development of exudative retinal detachment from uveal melanoma. Histopathological studies show that loops and networks are less common in tumours enucleated after irradiation and that they are frequently repeated in metastases of uveal melanoma. Avenues for immediate future research include detailed elucidation of the histogenesis of microvascular patterns and determination of these patterns in metastatic melanoma to identify new histopathological characteristics for prognostication when clinical metastases have developed.

Treatment options for choroidal malignant melanoma: a case report featuring transpupillary thermotherapy

BACKGROUND

Choroidal melanoma is the most common primary ocular tumor in adults. These tumors are almost always unilateral and develop spontaneously or arise from pre-existing nevi. Historically, treatment for choroidal melanoma was enucleation. New therapies have been developed to treat choroidal melanoma and to preserve the eye. Currently, these treatment options include brachytherapy and transpupillary thermotherapy.

CASE REPORT

A 51-year-old man came to the eye clinic with symptoms of mildly decreased fluctuating vision and floaters with no flashes in the temporal visual field of the right eye. Best-corrected visual acuities were 20/30 O.D. and 20/20 O.S. A small-to-medium choroidal lesion was found in the right eye. Ultrasonography and A-scan showed this lesion to be a choroidal malignant melanoma. The patient's surgical options included enucleation, brachytherapy, and transpupillary thermotherapy. The patient opted to have transpupillary thermotherapy to preserve the eye, and subsequently underwent two procedures that eventually obliterated the melanoma, resulting in best-corrected visual acuity of 20/40.

CONCLUSION

Transpupillary thermotherapy is an excellent option for treatment of small-to-medium choroidal melanomas. Brachytherapy is also an option for treatment, but with increased ocular side effects and complications. Enucleation is still commonly performed on medium and/or large choroidal melanomas.

Hemorrhagic complication in an unsuspected macular choroidal melanoma

PURPOSE

To report a rare presentation of a hemorrhagic complication in a patient with unsuspected macular choroidal melanoma.

DESIGN

Interventional case report.

METHODS

A 32-year-old Chinese woman presented with disturbance of her left central vision. A hemorrhagic mass at the macula was noticed that was evacuated by submacular surgery.

RESULTS

The mass expanded rapidly into a mushroom configuration after surgery. Fine-needle aspiration confirmed the diagnosis of malignant choroidal melanoma, and enucleation followed. Histology demonstrated moderately large epithelioid tumor cells with prominent nucleoli. The sclera was intact, and the optic nerve was not involved. The patient has been followed for 5 years without signs of local recurrence or metastasis.

CONCLUSION

We should be alert for atypical presentations of choroidal melanoma. Unnecessary or inadvertent surgical intervention may induce tumor growth and subsequent local spread or metastasis.

Combined plaque radiotherapy and transpupillary thermotherapy in choroidal melanoma: 5 years' experience

AIM

To evaluate the results of combined plaque radiotherapy and transpupillary thermotherapy (TTT) in 50 consecutive patients 5 years after treatment.

METHODS

50 adult patients with choroidal melanoma were treated with ruthenium-106 ((106)Ru) plaque radiotherapy combined with TTT. A flat scar was the preferred end point of treatment. The mean tumour thickness was 3.9 mm (range 1.5-8.0 mm), the mean tumour diameter was 11.3 mm (range 5.8-15.0 mm). TTT was performed with an infrared diode laser at 810 nm, a beam diameter of 2-3 mm, and 1 minute exposures. Tumours >5 mm thick received an episcleral contact dose of 800 Gy (106)Ru; tumours <or=5 mm thick received a contact dose of 600 Gy (106)Ru. TTT was repeated in case of incomplete tumour regression after combined therapy.

RESULTS

Complete tumour regression was obtained in 45 patients. It required one, two, or three TTT sessions in 32, 11, and two patients, respectively. In tumours <or=3 mm thick complete flattening was achieved significantly faster than in tumours >3 mm thick (log rank test p = 0.01). Eight melanomas were amelanotic, seven of which required multiple TTT sessions. In one patient the tumour recurred at the central margin of the treated area; this eye was enucleated. In one patient the tumour failed to regress 6 months after treatment and enucleation was performed at the patient's request. Three eyes developed severe proliferative retinopathy. Radiation maculopathy caused a loss of the best corrected visual acuity: before treatment 31 patients had a best corrected visual acuity of 20/60 or better but in only 12 patients did it remain in this range 5 years after treatment. Three patients developed distant metastasis to the liver.

CONCLUSION

The 5 year results for combined plaque radiotherapy and TTT as treatment for choroidal melanoma are favourable in terms of complete tumour regression and low rate of recurrences; however, there was considerable loss of visual acuity as a result of radiation maculopathy.

Transpupillary thermotherapy versus plaque radiotherapy for suspected choroidal melanomas

PURPOSE

To examine the outcomes and complications of transpupillary thermotherapy for treatment of small choroidal melanomas.

DESIGN

Retrospective case-matched comparative study and retrospective observational study.

PARTICIPANTS

The case-matched study consisted of 36 patients treated with either transpupillary thermotherapy or plaque radiotherapy (18 patients per group). The observational study consisted of 21 patients treated with transpupillary thermotherapy alone (primary transpupillary thermotherapy) and 9 patients treated with transpupillary thermotherapy plus plaque radiotherapy (adjuvant transpupillary thermotherapy).

MAIN OUTCOME MEASURES

Visual acuity, local tumor control, and metastasis.

RESULTS

The case-matched groups did not differ significantly with respect to age, gender, initial visual acuity, tumor location, or length of follow-up (mean, 33 months for transpupillary thermotherapy vs. 40 months for plaque radiotherapy). There was no significant difference in final visual acuity (P = 0.810) or postoperative visual acuity change (P = 0.919) between the 2 groups. In the observational study, the mean follow-up was 32 months (range, 4-58 months). Indications for primary transpupillary thermotherapy included documented growth (10 patients) and the presence of >/=3 risk factors for growth (11 patients). Retinal complications occurred in 16 patients (76%). The mean posttreatment visual acuity change was minus 2 lines (range, minus 9 to plus 7 lines). Local failure occurred in 6 patients (29%). Local failure was associated with an increased number of transpupillary thermotherapy spots per session (P = 0.023) and decreased tumor pigmentation (P = 0.001). Indications for adjuvant transpupillary thermotherapy included tumor radioresistance (6 patients) and the presence of risk factors for local failure (3 patients). All 9 tumors that received adjuvant transpupillary thermotherapy regressed rapidly, with no local failures. The mean postoperative visual acuity change was -1.9 lines (range, -9 to +5 lines). No patient in either study developed metastasis.

CONCLUSIONS

The recent interest in transpupillary thermotherapy as primary therapy for choroidal melanoma is based largely on the assumption that transpupillary thermotherapy may provide better visual outcomes than plaque radiotherapy. However, this study found no significant difference in visual outcomes between transpupillary thermotherapy and plaque radiotherapy. Further, the local failure rate with transpupillary thermotherapy was substantially higher than with plaque radiotherapy. The most promising role for transpupillary thermotherapy seems to be as an adjunct to plaque radiotherapy. The appropriate indications for transpupillary thermotherapy in the management of choroidal melanoma need to be re-evaluated.

Mortality after deferral of treatment or no treatment for choroidal melanoma

PURPOSE

To report mortality of patients who were eligible for enrollment in the Collaborative Ocular Melanoma Study (COMS) clinical trials of medium-sized choroidal melanoma or large-sized choroidal melanoma but chose to defer treatment or receive no melanoma treatment.

DESIGN

Prospective nonrandomized multicenter cohort study as an adjunct to the COMS randomized clinical trials.

METHODS

Patient follow-up procedures included examinations, correspondence, telephone contacts, and National Death Index searches. Primary outcome was patient death measured by all-cause mortality. Secondary outcomes were melanoma treatment and melanoma metastasis.

RESULTS

Of 77 patients eligible for the COMS clinical trials who chose to defer or receive no melanoma treatment, 61 were appropriate candidates and 45 (74%) enrolled in the natural history study. Forty-two patients (42 eyes) had medium melanoma, and median follow-up was 5.3 years (range, 4-10.7 years). Twenty-two patients (52%) had subsequent melanoma treatment, and 20 (48%) had no melanoma treatment. For the 42 patients, the Kaplan-Meier estimate of 5-year mortality was approximately 30% (95% confidence interval [CI], 18%-47%). For the COMS medium melanoma trial, 5-year mortality was 18% (95% CI, 16% -20%), not statistically significantly different from the natural history study patients. After adjusting for differences in age and longest basal diameter, the 5-year risk of death for natural history study patients vs COMS trial patients was 1.54 (95% CI, 0.93-2.56). Three patients had large melanoma. Melanoma metastasis was confirmed or suspected in eight (42%) of 19 deaths.

CONCLUSION

Greater mortality and higher risk of death for natural history study patients are probative but not conclusive evidence of a beneficial, life-extending effect of medium melanoma treatment.

Changing concepts in the management of choroidal melanoma

PURPOSE

To review emerging information related to changing concepts in the management of choroidal melanoma.

DESIGN AND METHODS

This perspective reviews and discusses selected studies from the past two decades that have influenced management strategies for large, medium, and small-size choroidal melanomas.

RESULTS

Large choroidal tumors continue to be managed primarily by enucleation. The large tumor trial of the Collaborative Ocular Melanoma Study (COMS) demonstrated neither a positive nor negative effect on 5- and 8-year mortality rates among more than 1000 patients whose eyes containing large choroidal melanomas were randomized to treatment between enucleation alone or enucleation preceded by external radiation. The medium-size tumor trial of the COMS randomized more than 1300 patients between iodine-125 brachytherapy and enucleation. Mortality rates following brachytherapy did not differ from mortality rates following enucleation for up to 12 years after treatment. Iodine-125 has become the most commonly used isotope for brachytherapy in North America. Ten-year follow-up of eyes treated with helium ion and 20 years of experience with proton beam confirm the relative safety and efficacy of these modalities for treatment of choroidal melanoma. Although there is a trend toward earlier treatment of small melanomas, controversy exists regarding the indications for treatment as well as the choice of specific therapy. Recurrences of melanoma after eye-sparing treatment appear to be associated with an increased rate of metastatic disease. Effective adjunctive therapy to prevent or treat melanoma metastasis is lacking.

CONCLUSIONS

Choroidal melanoma is a lethal tumor. Although evidence suggests that patients with untreated choroidal melanomas have a poorer prognosis than patients who receive treatment, our current treatments are unable to prevent tumor-related deaths for many patients. The use of preoperative external radiation as an adjunct to enucleation for large choroidal melanomas is unsupported by data from the COMS trial. The use of radiation with either brachytherapy or charged particles for the management of medium-size choroidal melanomas is well supported on the basis of long-term follow-up studies. There is a trend toward treatment of smaller choroidal melanomas. Treatment of melanomas should be directed toward minimizing the potential for recurrences as recurrent melanomas are associated with an increased rate of metastatic disease. Gains in our ability to manage choroidal melanoma will likely be modest at best until effective systemic therapies can be identified.

Microphthalmia transcription factor analysis in posterior uveal melanomas

PURPOSE

The protein encoded by the Microphthalmia gene (MITF) is a transcription factor essential for the development and survival of melanocytes. It serves as a master regulator in modulating extracellular signals. Because of its central role in melanocytes survival and to assess its potential use as a histopathological marker for melanoma, MITF expression was examined in human choroidal melanomas.

METHODS

Fifty-seven paraffin-embedded sections of choroidal melanoma specimens and 1 choroidal melanoma cell line were analyzed using immunochemistry and RT-PCR. Normal choroids and normal choroidal melanocyte cells were used as control.

RESULTS

Sixty-five percent of the tumoral specimens stained positively for MITF with a predominant nuclear pattern of reactivity. MITF-M and MITF-A isoforms were detected by RT-PCR in all specimens examined. Using a chimeric protein resulting from the fusion of each Mitf protein with the GFP, Mitf-M exhibited an exclusive nuclear staining whereas Mitf-A exhibited a mixed nuclear and cytoplasmic staining. No correlation between MITF-positivity and parameters such as cell type, largest tumor diameter, sclera invasion, mitotic figures was observed. In contrast, a significant negative association was found between MITF staining and the pigmentation (p=0.02) and a positive correlation between MITF staining and the proliferative marker Ki67 was found (p=0.02).

CONCLUSION

MITF may be implicated in choroidal melanoma pigmentation and proliferation. Further analysis should provide new insights into the mechanisms underlying the molecular and cellular changes of choroidal melanomas.

The American Brachytherapy Society recommendations for brachytherapy of uveal melanomas

PURPOSE

This article presents the American Brachytherapy Society (ABS) guidelines for the use of brachytherapy for patients with choroidal melanomas.

METHODS

Members of the ABS with expertise in choroidal melanoma formulated brachytherapy guidelines based upon their clinical experience and a review of the literature. The Board of Directors of the ABS approved the final report.

RESULTS

Episcleral plaque brachytherapy is a complex procedure and should only be undertaken in specialized medical centers with expertise in this sophisticated treatment program. Recommendations were made for patient selection, techniques, dose rates, and dosages. Most patients with very small uveal melanomas (<2.5 mm height and <10 mm in largest basal dimension) should be observed for tumor growth before treatment. Patients with a clinical diagnosis of medium-sized choroidal melanoma (between 2.5 and 10 mm in height and <16 mm basal diameter) are candidates for episcleral plaques if the patient is otherwise healthy and without metastatic disease. A histopathologic verification is not required. Small melanomas may be candidates if there is documented growth; some patients with large melanomas (>10 mm height or >16 mm basal diameter) may also be candidates. Patients with large tumors or with tumors at peripapillary and macular locations have a poorer visual outcome and lower local control that must be taken into account in the patient decision-making process. Patients with gross extrascleral extension, ring melanoma, and tumor involvement of more than half of the ciliary body are not suitable for plaque therapy. For plaque fabrication, the ophthalmologist must provide the tumor size (including basal diameters and tumor height) and a detailed fundus diagram. The ABS recommends a minimum tumor (125)I dose of 85 Gy at a dose rate of 0.60-1.05 Gy/h using AAPM TG-43 formalism for the calculation of dose. NRC or state licensing guidelines regarding procedures for handling of radioisotopes must be followed.

CONCLUSIONS

Brachytherapy represents an effective means of treating patients with choroidal melanomas. Guidelines are established for the use of brachytherapy in the treatment of choroidal melanomas. Practitioners and cooperative groups are encouraged to use these guidelines to formulate their treatment and dose reporting policies. These guidelines will be modified as further clinical results become available.

Clinicopathologic findings in choroidal melanomas after failed transpupillary thermotherapy

PURPOSE

To review the clinicopathologic features of eyes enucleated after failed transpupillary thermotherapy.

DESIGN

Retrospective review.

METHODS

Pathology reports in the L.F. Montgomery Laboratory between 1998 and 2002 were searched for enucleated eyes with choroidal melanoma that had been treated only by transpupillary thermotherapy (TTT) prior to enucleation. The clinical features of the patients, including ultrasonography examination, were reviewed and compared with the pathologic findings.

RESULTS

Seven eyes from seven patients had been enucleated, representing 8% of eyes treated with TTT at our institute during the period studied. The primary indication for enucleation was tumor growth. The melanomas tended to grow laterally, with minimal if any increase in thickness. Five of the seven eyes histologically demonstrated extrascleral extension, which was detected by ultrasonography prior to enucleation in only one of those eyes.

CONCLUSIONS

Choroidal melanoma may continue to grow along a path of least resistance after TTT. The melanoma may extend laterally in the choroid and through emissary canals. Early extrascleral extension may be difficult to detect by ultrasonography.

Uveal melanoma and poor treatment compliance: an atypical outcome with literature review

BACKGROUND

A uveal melanoma is the most common primary intraocular malignancy and is the primary intraocular disease that can be fatal in adults. Until recently, data were limited regarding growth characteristics and at what stage metastases are likely to occur.

CASE REPORT

A 49-year-old white male presented on January 19, 1989, for a second opinion regarding a spot that had been discovered in the right eye 13 months prior. Ophthalmologic evaluation and echography were consistent for a uveal melanoma of 5 mm elevation and 13.5 x 6 mm in diameter. The patient refused treatment or enrollment into the Collaborative Ocular Melanoma Study. On December 9, 1991, the eye was enucleated with a modified exenteration due to severe proptosis, tumor thickness of 22 mm, and three areas of extrascleral extension. The patient refused postoperative radiation treatment and refused clinical follow-up. This case was reviewed from the initial evaluation date through the last clinical visit. The patient was recently interviewed with respect to his use of homeopathic medicine, change in lifestyle, and the effect he felt it might have had on his life.

DISCUSSION

The literature published by the Collaborative Ocular Melanoma Study regarding the histopathologic characteristics of eyes enucleated and the initial mortality findings of a large choroidal melanoma indicate that this is a most unusual case. The patient has defied the mortality findings of the most recent and largest study to date (mean survival rate, 82 months). The patient is still alive 181 months after the original finding of the lesion and refusal of advised treatment recommendations in favor of homeopathic medicine.

Small choroidal melanoma with massive extraocular extension: invasion through posterior scleral emissary channels

Massive orbital extension arising from a small posterior pole uveal melanoma is rare. A 75-year-old male followed for an asymptomatic choroidal nevus developed a two and a half month history of mild decrease in visual acuity. Upon clinical examination minimal enlargement of the tumor with surrounding serous retinal detachment was observed. Pre-operative magnetic resonance imaging disclosed massive extrascleral extension. Histopathology revealed that the tumor was composed of spindle B malignant melanoma cells. Multiple serial sections of the entire tumor area failed to demonstrate permeation through scleral lamellae. Instead, peripapillary perivascular short posterior ciliary vessel invasion was observed. This route of dissemination may explain the rapid growth and clinically undocumented behavior of small malignant melanomas at this location.

Expression of the c-kit receptor in choroidal melanomas

The KIT gene encodes c-kit, a transmembrane receptor that has tyrosine kinase activity and plays a role in haematopoiesis, gametogenesis and melanogenesis. The c-kit protein is found in normal cutaneous and choroidal melanocytes, and there is evidence that expression is lost in melanoma. Expression of c-kit was analysed in 57 paraffin-embedded sections of choroidal melanoma specimens and three choroidal melanoma cell lines using immunochemistry and Western blotting. Of the tumour specimens, 75% stained positively for c-kit with a membrane pattern of reactivity. Of the six patients who underwent proton beam therapy before enucleation, five tumours exhibited no c-kit immunoreactivity and the other tumour demonstrated weak staining. Of the three melanoma cell lines used, c-kit expression was observed in only one. No correlations between c-kit positivity and parameters such as cell type, largest macroscopic tumour dimension, scleral invasion or pigmentation were observed. In contrast, a significant positive association was found between c-kit staining and mitotic activity (P = 0.02). However, c-kit expression did not significantly influence survival when evaluated by univariate analysis. In conclusion, c-kit is expressed in most choroidal melanoma tumours. Further analysis should provide new insights into the mechanisms underlying the molecular and cellular changes in choroidal melanomas.

Late orbital recurrence of a choroidal melanoma following internal resection: report of a case and review of the literature

The management of uveal melanomas always has been a challenge to the clinicians and has evolved from the era of eye-removing surgeries to elimination of the tumor by the body's own immune system through vaccines. Evaluating the outcome of each strategy improves our understanding of the disease process and helps us to improvise on the existing modalities of treatment. Internal resection of choroidal melanomas has been described as one of the treatment modalities for this malignant tumor. Tumor recurrences reported following this surgical procedure have been uncommon. We report a rare case of a 61-year-old Caucasian woman who presented with a 2-month history of progressive, painful proptosis in her right eye. Thirteen years ago she underwent internal resection of an intraocular choroidal melanoma in the same eye and had no evidence of metastatic disease. Magnetic resonance imaging demonstrated a mass occupying the superotemporal portion of the right orbit adjacent to the globe and behind the area of prior internal resection. Biopsy of the lesion and the subsequent A right orbital exenteration confirmed the diagnosis of recurrent malignant melanoma. Twenty-four months following exenteration the patient continues to be free of metastatic disease. Since internal surgical resection was described in 1984, this is the latest known recurrence of a posterior choroidal melanoma. In this review, we highlight the clinical features of this rare case and discuss in brief the rationale of various treatment modalities for choroidal melanoma.

Retinal vascular alterations associated with dome-shaped and mushroom-shaped choroidal melanomas

PURPOSE

Retinal vascular abnormalities are associated with choroidal melanoma. Although tumor ischemia, resulting in soluble angiogenic factor production, is a proposed etiology of these abnormalities, other sources of ischemia may also contribute. Mushroom-shaped choroidal melanomas have increased loss of the overlying choriocapillaris and increased subretinal fluid when compared to dome-shaped tumors; factors that may result in outer retinal ischemia, angiogenic factor production and resultant retinal vascular abnormalities. The differing amounts of retinal vascular abnormalities overlying dome-shaped compared to mushroom-shaped melanomas were determined to evaluate this hypothesis.

METHODS

Retinal vascular abnormalities observed on fluorescein angiograms of eyes with choroidal melanoma were compared to the tumor configuration and presence of subretinal fluid.

RESULTS

23 eyes of 22 patients were included in the study. Retinal vascular abnormalities observed included dilated capillaries, telangiectatic capillaries, capillary nonperfusion, microaneurysms, neovascularization, lipid exudation and late staining of dye within the retina. Retinal vascular abnormalities were present in 4 of 14 eyes with dome-shaped tumors (29%) and in 8 of 9 eyes with mushroom-shaped tumors (89%). (Fisher's Exact Test, p = 0.009). Retinal vascular abnormalities were present in 2 of 10 eyes without subretinal fluid (20%) and in 10 of 13 eyes with subretinal fluid (77%). (Fisher's Exact Test, p = 0.012).

CONCLUSIONS

Retinal vascular abnormalities are associated with mushroom-shaped choroidal melanomas more commonly than dome-shaped tumors. Outer retinal ischemia may result from choriocapillaris loss or the presence of subretinal fluid, contributing to soluble angiogenic factor production and resultant retinal vascular abnormalities in these eyes.

SUMMARY STATEMENT

Retinal vascular abnormalities are associated with mushroom-shaped choroidal melanomas more commonly than dome-shaped tumors. These retinal vascular abnormalities may be related to an increase in outer retinal ischemia associated with mushroom-shaped tumors.

Pancreatic resection for metastatic melanoma

BACKGROUND

The pancreas is an occasional site of metastases from melanoma. It may be the only location of metastatic disease, but more often the melanoma metastasis to other organs as well. Treatment options are somewhat limited, and the role of operative treatment is poorly defined.

CASE OUTLINES

Two patients presenting with abdominal pain were found to have pancreatic lesions. A 45-year-old woman had a pylorus-preserving pancreatoduodenectomy for a mass in the head of pancreas; concurrent liver nodules were treated by segmental liver resection. A 55-year-old man had a total pancreatectomy for multiple pancreatic tumours. Both patients gave a history of ocular melanoma, diagnosed >10 years previously. They had no evidence of malignancy elsewhere. Histology of resected specimens confirmed metastatic melanoma with features consistent with an ocular primary. All resection margins were clear of malignancy, and no lymph node metastases were detected. At 6 months follow-up there were no signs of tumour recurrence.

DISCUSSION

Complete surgical resection offers potential cure in selected patients with metastatic melanoma involving the pancreas, when there is no evidence of widespread disease.

Thermotherapy in the management of choroidal melanoma

During the past 20 years of enucleation, which was the standard treatment for choroidal melanoma over more than a century, has largely been replaced by eye salvaging therapies such as radiotherapy or local resection. In 1995 transpupillary thermotherapy (TTT) using an infrared diode laser was introduced as a new conservative therapy for patients with choroidal melanoma. TTT can be defined as a heat treatment modality, which is delivered through a dilated pupil to the tumour surface. The technique uses a wide diode laser beam diameter with a low irradiance and a long exposure time. TTT induces tumour necrosis at sub-photocoagulation levels by a direct cell destructive effect with only a few ocular complications. TTT can be performed as sole therapy or combined with plaque radiotherapy, thus permitting a lower radiation dose. For amelanotic tumours dye-enhanced TTT with indocyanine green can be used. In this paper we review the role of sole or combined TTT, related to the current other treatment modalities for choroidal melanoma.