Lack of association between intraocular melanoma and cutaneous dysplastic nevi

The dysplastic nevus: from historical perspective to management in the modern era: part II. Molecular aspects and clinical management

The dysplastic nevus is a discreet histologic entity that exhibits some clinical and histologic features overlapping with common nevi and melanoma. These overlapping features present a therapeutic challenge, and with a lack of accepted guidelines, the management of dysplastic nevi remains a controversial subject. Although some differences between dysplastic and common nevi can be detected at the molecular level, there are currently no established markers to predict biologic behavior. In part II of this continuing medical education article, we will review the molecular aspects of dysplastic nevi and their therapeutic implications. Our goal is to provide the clinician with an up-to-date understanding of this entity to facilitate clinical management of patients with nevi that have histologic dysplasia.

Relationship of uveal and cutaneous malignant melanoma in persons with multiple primary tumors

Uveal and cutaneous melanomas differ in tumor biology, immunophenotypes and the demographic correlates of their occurrence. As a means to examine the possibility of some shared etiologic factors, we wished to learn if the 2 cancers occurred in the same individual more often than would be expected by chance. Data from the Surveillance, Epidemiology and End Results (SEER) program from 1973-1998 were utilized for this purpose. The number of persons who went on to develop a second melanoma was compared to that expected based on the incidence of each type of melanoma in the general population, after adjusting for age, sex, calendar year and residence. Given an initial cutaneous melanoma, there was a 10-fold increased risk of developing a second cutaneous melanoma (95% confidence interval [CI] = 9.4-10.6). Persons with uveal melanoma went on to develop cutaneous melanoma 4.6 times (95% CI = 2.9-6.8) more often than the population at large. In contrast, persons with cutaneous melanoma were not subsequently diagnosed with uveal melanoma at an appreciably elevated rate (standardized incidence ratio [SIR] = 1.4; 95% CI = 0.5-3.0). While these data offer some support for the hypothesis that uveal and cutaneous melanomas have 1 or more etiologies in common, the lack of symmetry in the pattern of second uveal and second cutaneous melanomas remains unexplained.

Ocular melanomas and melanocytic lesions of the eye

This article describes several melanocytic lesions of the eye. Benign and malignant lesions will be discussed as well as a review of the dysplastic nevus syndrome and its proposed association with ocular melanoma. Ocular melanomas arise from the same embryologically derived melanocytes as their cutaneous counterparts. However, ocular and cutaneous melanomas differ in many respects. The diagnosis and management of these ocular tumors rely heavily on the ophthalmologist. However, knowledge of melanocytic lesions will aid the dermatologist in detection and in proper referral of these patients.

Conjunctival melanoma

Conjunctival melanoma is an uncommon tumor that is likely to recur and carries an overall mortality rate of approximately 30%. The seemingly unpredictable and enigmatic character of this entity has initiated much debate over the past decades regarding the etiology, histogenesis, prognosis, and preferred management. This review outlines the historical perspective; incidence and demographics; etiologic factors; histogenesis; cytogenetic findings; clinical characteristics; histopathologic and ultrastructural features; differential diagnoses; classifications; management of primary, recurrent, and systemic disease; survival after conjunctival melanoma; and diverse factors of potential prognostic significance. Finally, a brief outlook on present and future research objectives is provided.

Prevalence of primary acquired melanosis and nevi of the conjunctiva and uvea in the dysplastic nevus syndrome. A case-control study

PURPOSE

To investigate whether conjunctival and uveal nevi and primary acquired melanosis are more common in individuals with the dysplastic nevus syndrome than in control subjects derived from the general population.

METHODS

Power calculations were used to determine the sample size. After invitation, 162 individuals with the dysplastic nevus syndrome and 119 control subjects, matched for sex and age but otherwise randomized from the Stockholm county census file, were entered into the study. All individuals were examined in a masked fashion by the same ophthalmologist, and the presence of conjunctival and uveal melanocytic lesions and the iris color, skin type, and hair color of each individual were recorded. Contingency tables and odds ratios were used for statistical evaluation.

RESULTS

The proportions of individuals with the dysplastic nevus syndrome featuring primary acquired melanosis of the conjunctiva, or nevi of the iris and choroid were not significantly different from those of control subjects. However, individuals with the dysplastic nevus syndrome appeared to have a more sun-sensitive skin type and a reddish or blond hair color more often than control subjects.

CONCLUSION

In contrast to previous reports, this study suggests that ocular melanocytic lesions are no more common in individuals with the dysplastic nevus syndrome than in the general population. Therefore, this work does not provide support that periodic ophthalmic surveillance of individuals with the dysplastic nevus syndrome for the purpose of detecting conjunctival or uveal melanomas, or their precursors, is meaningful.

Uveal melanoma and familial atypical mole and melanoma (FAM-M) syndrome

We conducted this study to determine whether occurrence of primary uveal melanoma in the setting of familial atypical mole and melanoma (F A M-M) syndrome (an autosomal dominant cutaneous preneoplastic syndrome) follows a pattern of a hereditary cancer predisposition syndrome. A retrospective review of 4600 consecutive patients with primary uveal melanoma revealed eight patients with biopsy-proven F A M-M syndrome. The clinical profile of these patients was studied and their kindreds analyzed. In patients with F A M-M syndrome, the uveal melanoma occurred at a relatively young age (mean 40 years; range 10-52 years). The diagnosis of F A M-M syndrome preceded or followed the diagnosis of uveal melanoma by as much as 10 years. None of the patients had an associated nonmelanocytic malignancy. Three of the eight patients had a positive family history of melanoma (cutaneous melanoma (2) and uveal melanoma (1). The authors conclude that the occurrence of primary uveal melanoma in the setting of F A M-M syndrome does not follow a clear pattern of a hereditary cancer predisposition syndrome.

Risk of ocular melanoma in relation to cutaneous and iris naevi

A case-control study was set up to assess the risk of eye melanoma in relation to the number and type of cutaneous melanocytic naevi and pigmented lesions of the iris. Cases comprised 211 unselected ocular melanoma patients attending the Ocular Oncology Clinic at Moorfields Eye Hospital, London, during November 1990 to October 1991 and diagnosed after August 1986. Hospital and general practice controls (416) were recruited in the North East Thames Region of the UK. Cutaneous naevi greater than or equal to 2 mm in diameter were counted on the skin. Clinically atypical and congenital naevi were recorded separately. Pigmented lesions of the iris were counted. The relative risk for ocular melanoma increased with numbers of atypical naevi and numbers of common naevi. Ten percent of cases but 3% of controls had at least 100 naevi of 2 mm or greater diameter. Seven percent of cases and 0.4% of controls had 4 or more atypical naevi. Pigmented lesions of the iris were significantly more common in cases than controls. Nine percent of cases had the Atypical Mole syndrome (AMS) phenotype compared with 1% of controls. Six cases had concurrent cutaneous melanoma primaries. We conclude that atypical and iris naevi are important risk factors for eye melanoma and that patients with eye melanoma are at increased risk of cutaneous melanoma. Dermatological examination for the AMS phenotype and cutaneous melanoma should be recommended in eye melanoma patients with large numbers of pigmented lesions of the skin or family history of melanoma.

Atypical mole syndrome: risk factor for cutaneous malignant melanoma and implications for management

The incidence of malignant melanoma is increasing faster than that of any other cancer. It is important to identify subsets of the population at high risk of its development so that they can be observed more closely to identify early melanomas when they are curable. It has been reported worldwide that persons with the atypical mole (dysplastic nevus) syndrome are such a subset at increased risk. A risk gradient for the development of melanoma exists and varies from persons with one or two atypical moles and no family history of melanoma at one end of the spectrum to persons with the familial atypical multiple-mole melanoma syndrome at the other. Guidelines for the management of atypical mole syndrome are presented.

Iris melanoma in a ten-year-old boy with familial atypical mole-melanoma (FAM-M) syndrome

A ten-year-old boy was referred with an enlarging amelanotic iris tumor and secondary glaucoma in the left eye. After excisional biopsy it proved histopathologically to be an iris melanoma. The patient also had multiple nevi on his trunk, scalp, and buttocks suggestive of familial atypical mole melanoma (FAM-M) syndrome and confirmed histopathologically. To the authors' knowledge, this is the first report of iris melanoma in association with FAM-M syndrome. The young age at tumor onset is suggestive of a predisposing condition such as FAM-M syndrome. The association of uveal melanoma with FAM-M syndrome is discussed.

Cytogenetic findings in primary uveal melanoma

We analyzed cytogenetic abnormalities in 10 cases of primary uveal melanoma. Clonal chromosomal abnormalities were present in nine cases. Chromosome 6 was most commonly affected (seven cases) and included gain of material from 6 and/or loss of material from 6q. Trisomy of chromosome 8 or gain in material from 8q, mostly in the form of an i(8q) resulting in three to five copies of the 8q segment was seen in six cases. Monosomy of chromosome 3 and rearrangements of chromosome 9 were less frequent and were altered in three cases each. Clinical, histopathologic, and cytogenetic abnormalities are correlated.

Simultaneous occurrence of primary choroidal and cutaneous malignant melanoma and skin metastasis

This case report describes the clinical and histopathological findings in a 65-year-old woman enucleated for a malignant choroidal melanoma. Simultaneously, an excision was performed of a cutaneous melanoma together with a satellite nodule presumed to be a metastasis from the cutaneous, superficial spreading melanoma. Six months later, chemotherapy for liver metastasis was given without effect. There were no signs of dysplastic nevus syndrome. A 39-year-old cousin, however, had been enucleated for a malignant choroidal melanoma. This sporadic case might suggest a common etiologic factor in the pathogenesis of multicentric melanomas.

Risk of melanoma and other cancers in melanoma-prone families

We evaluated the risk of developing melanoma over time in members of 23 melanoma-prone families. All 23 families had dysplastic nevi as well as melanoma. Forty-seven melanomas occurred prospectively, all in family members with dysplastic nevi. The prospective melanomas were markedly thinner than the melanomas diagnosed prior to or at the time of the subject's entry into the study. The cumulative risk of melanoma by age 50 years among people with dysplastic nevi was 48.9% +/- 4.2%. Overall, the relative risk of a prospective melanoma among family members with previous melanoma was 229 (95% confidence interval 110-422). The risk varied by time interval and was 362 in the first 5 years, decreasing to 120 after 5 years. The risk of developing melanoma was 85 times increased (95% confidence interval 41-156) in family members with dysplastic nevi and also declined over time in this group. There was no significant excess of cancers other than melanoma. Close surveillance of these high-risk families has led to diagnosis of melanoma at an earlier developmental stage, which should result in a decrease in mortality over time.

Conjunctival and uveal melanoma in the dysplastic nevus syndrome

The dysplastic nevus syndrome was conceptualized in the late 1970s, and the subsequent proposal of a genetic relationship with ocular melanoma has stimulated debate in the literature which remains unresolved. We present the case of a 60-year-old man with histologically proven sporadic dysplasic nevus syndrome and a prior history of nine cutaneous melanomas, who developed a large, exophytic melanoma of the cornea and limbal conjunctiva. Cytogenetic analysis of this melanoma revealed a clonal 1;14 translocation. We believe this is the first reported case to use cytogenetic techniques in the analysis of conjunctival melanoma, either associated with dysplastic nevus syndrome or in isolation. We review the clinical literature as well as the cytogenetic and molecular genetic data related to the possible association of cutaneous melanoma, conjunctival and uveal melanoma and the dysplastic nevus syndrome.

Ocular melanoma in families with dysplastic nevus syndrome

Five families with the dysplastic nevus syndrome, in each of which one member had ocular melanoma, are reported. These five families were examined within a 3-year period in one medical center. To date only five other families with such a combination have been reported. We suggest a causal relation between ocular melanoma and the familial dysplastic nevus syndrome.

Ocular melanoma in Alberta: a 38 year review pointing to the importance of tumor size and tumor histology as predictors of survival

A large number of cases of ocular melanoma have been entered in The Provincial Cancer Registry of Alberta over the past 40 years. This study was undertaken in order to describe further the natural history of this disease and derive management recommendations for use at the provincial level. A retrospective chart review was carried out on all cases of ocular melanoma registered through The Alberta Provincial Cancer Registry between 1949 and 1987. Two hundred fifty-one cases were identified: 143 were males and 108 were females. The mean age of the patients at diagnosis was 60. The majority of the melanomas arose from the choroid of the eye (82%) with the remainder arising from the iris, conjunctiva and ciliary body, respectively. According to the Callender classification for ocular melanomas, the majority of the melanomas were of the spindle cell type (53%), the others being either mixed cell (23%), epithelioid (8%), or fascicular (1%). Survival rates differed depending on the cell type. Spindle cell tumors demonstrated a mean survival time of 5.2 years; epithelioid tumors 4.8 years and the mixed cell tumors appeared to be the most aggressive with a mean survival time of 2.7 years after diagnosis. The majority of deaths from ocular melanoma occurred within 5 years of diagnosis, although 14% of patients in this review presented with metastases more than 10 years after diagnosis. Some of the cases of ocular melanoma could be classified pathologically as small, medium, or large. Patients with large ocular melanomas had a 5 year survival rate of 33% compared to 70% and 66% for patients with small and medium sized tumors. Of note, 43% of patients with large ocular melanomas who were dead from their disease within 5 years of diagnosis were also found to have mixed cell tumors. These findings call for a longer follow-up period for ocular melanomas and point to the importance of cell type and tumor size as predictors of survival and as guides in planning prophylactic therapeutic interventions.

Other cancers in uveal melanoma patients and their families

To determine associations with other cancers, 400 consecutive uveal melanoma patients examined at Wills Eye Hospital between 1984 and 1985 were surveyed regarding personal and family history of cancer. Responses were received from 333 (83%). Sixty patients reported 43 nonbasal cell second primary cancers, which were confirmed pathologically or by physician records. The overall prevalence of nonbasal cell cancers diagnosed in uveal melanoma patients by December 1985 was over two times greater than the expected prevalence, based on the Connecticut Tumor Registry data for an age- and sex-matched population. Gynecologic cancers tended to be more common in uveal melanoma female patients than in the comparison population. Although the observed prevalence of cutaneous melanoma was not significantly greater than expected, three cases with both primary cutaneous and uveal melanoma were reported. Family histories of cutaneous melanoma were confirmed in 14 patients, and uveal melanoma in two patients. Data suggested that the overall cancer prevalence in uveal melanoma patients may be increased, that hormonal factors may play a role in the genesis of this malignancy, and that there may be a link between cutaneous and uveal melanoma.

Mapping the gene for hereditary cutaneous malignant melanoma-dysplastic nevus to chromosome 1p

We used molecular genetic techniques and multipoint linkage analyses to locate the gene responsible for cutaneous malignant melanoma-dysplastic nevus. We evaluated 99 relatives and 26 spouses in six families with a predisposition to melanoma. Thirty-four family members had cutaneous malignant melanoma, and 31 of these 34 also had histologically confirmed dysplastic nevi. Twenty-four family members had dysplastic nevi alone. An analysis of the cosegregation of the cutaneous malignant melanoma-dysplastic nevus trait with 26 polymorphic DNA markers on the short arm of chromosome 1 demonstrated the presence of a gene for susceptibility to melanoma. The gene was located between an anonymous DNA marker (D1S47) and the gene locus for pronatrodilatin, a commonly used reference gene (PND), in chromosome band 1p36. The odds were greater than 260,000:1 in favor of linkage at this location.

Dysplastic naevi in a population-based survey

The prevalence of dysplastic naevi was studied in a population-based survey of 380 30 to 39-year-old and 50 to 59-year-old non-Maoris in Milton, a small town in the south of New Zealand. Photographs of all pigmented naevi greater than or equal to 4 mm in diameter were taken during the survey and subsequently evaluated by two experienced reviewers. Nine percent of the group (95% CI, 6%-13%) were judged to have one or more dysplastic naevi. Interobserver agreement over the diagnosis of dysplastic naevi was 85% (kappa = 0.55). Dysplastic naevi were associated with higher counts of moles greater than or equal to 2 mm in diameter; 50 or more such moles increased the likelihood of having three or more dysplastic naevi about 40-fold. Naevi judged to be dysplastic were, therefore, relatively common and were associated with increased numbers of common moles.

Familial uveal melanoma

The cause of uveal melanoma is unknown. In a few cases, however, factors are found in association with the disease which may play some part in the aetiology. One such factor is inheritance. Twelve families have been reported with adequate documentation during the last century in which two or more members have had uveal melanomas. At least some of these may be the result of an inherited disorder. On available data inheritance is most likely autosomal dominant with partial expressivity or incomplete penetrance. This report describes two more families each of which have two members with uveal melanomas.

Epidemiologic aspects of uveal melanoma

Although the underlying cause or causes of uveal melanoma have yet to be elucidated, important insights may be gained by examining the epidemiologic features of the disease. Uveal melanoma is an uncommon cancer with an incidence of only six cases per million population per year. It is most often diagnosed in the sixth decade and is somewhat more common in males. Apart from sporadic reports of family clusters, uveal melanoma is not considered an inherited disease. Whether some environmental exposure triggers the development of uveal melanoma remains an open question. Sunlight has been proposed as an environmental risk factor because sunlight is known to cause melanoma of the skin and both diseases are rare in nonwhite races. Unlike cutaneous melanoma, however, rates have not been increasing over time and do not vary by latitude. This paper evaluates the available evidence for sunlight and other potential risk factors for uveal melanoma, highlighting areas requiring further research.

Nonsimultaneous primary choroidal and cutaneous melanomas. Report of a case

The authors report a patient with nonsimultaneous choroidal and cutaneous melanomas. The patient did not display the dysplastic nevus syndrome phenotype, and there was a negative family history for cutaneous or uveal melanomas. This sporadic case might suggest a common etiologic factor in the pathogenesis of multicentric malignant melanomas.

Malignant melanoma of the choroid in an infant with the dysplastic naevus syndrome

A 7-month-old Algerian boy with numerous skin naevi from birth was found to have a malignant melanoma of the choroid, giving symptoms from the age of 3 months. The ocular and cutaneous tumours were shown to be melanocytic by a battery of histochemical tests and by electron microscopy. The rarity of the case is discussed on basis of the literature, and it is concluded that the case is unique because of the early age at which both the ocular tumour and the dysplastic naevus syndrome occurred.

Ocular findings in patients with dysplastic nevus syndrome

Ninety-two patients with biopsy-proven dysplastic nevus syndrome were evaluated ophthalmologically and compared to a non-dysplastic nevus syndrome control population. A statistically significant increase in the percentage of dysplastic nevus syndrome patients versus controls harboring conjunctival nevi (9.78% vs. 1.85%), iris nevi (31.52% vs. 12.96%), and choroidal nevi (18.48% vs. 4.63%) was found. Although not statistically significant, the number of iris nevi encountered per patient was greater for the dysplastic nevus syndrome group. All dysplastic nevus syndrome patients and their families should be evaluated ophthalmologically, with special attention being given to dilated indirect ophthalmoscopy.

Unusual melanocytic nevi of the conjunctiva

In one patient, an epithelioid cell nevus of the conjunctiva contained numerous large, unpigmented, mononucleated, binucleated, and multinucleated benign-appearing nevus cells with abundant cytoplasm and frequent intranuclear vacuoles. Despite their overall size, the cells manifested a low nuclear-cytoplasmic ratio. After a partial excision of the lesion, the remainder spontaneously regressed during a two-year period. Another patient's lesion was dominated by a proliferation of spindle nevus cells developing in a long-standing epibulbar nevus. The spindle cells were moderately pigmented, frequently located within walls of epithelial inclusion cysts, and had benign cytologic features. Finally, in a third patient with the cutaneous B-K mole syndrome, a dysplastic conjunctival nevus developed that featured intraepithelial, atypical melanocytic proliferation with superficial colonization of the substantia propria. This portion coexisted with a deeper, preexistent lesion in the substantia propria that was comprised of orderly nests of unpigmented cuboidal nevus cells surrounded by pigmented, spindle-shaped blue nevus cells--a so-called "mixed nevus."