Cutaneous melanoma and bilateral retinoblastoma

The triad of bilateral retinoblastoma, dysplastic naevus syndrome and multiple cutaneous malignant melanomas: a case report and review of the literature

We report a case of a patient with the triad of retinoblastoma, dysplastic naevus syndrome (DNS) and multiple cutaneous melanomas. The combination of retinoblastoma and DNS is a significant risk factor for the development of cutaneous melanoma. This risk extends to family members. We recommend that survivors of (inherited) retinoblastoma and their relatives are closely screened for the presence of dysplastic naevi.

Second primary tumors in patients with cutaneous malignant melanoma

BACKGROUND

Several studies report coexistent or subsequent primary tumors (SPT) among patients with malignant melanoma (MM), with the rate of incidence ranging from 1.5-20% depending on the sample size and the length and completeness of follow-up.

METHODS

The authors followed a cohort of patients with cutaneous MM who were diagnosed and treated at the City of Hope National Medical Center to determine the incidence rate of SPT and associated risk factors. Five hundred eighty-five patients (median age at diagnosis, 43 years) were diagnosed and treated for MM between 1952 and 1996 and followed for a median of 6.5 years (range, 0.0-37.0 years). Ninety-six percent of the cohort had been treated by surgery alone.

RESULTS

Thirty-seven patients developed an SPT. These included skin cancers (n = 23), carcinoma of the urinary bladder, breast carcinoma, and lymphoma (n = 3 each), lung carcinoma and prostate carcinoma (n = 2 each), and cervical carcinoma (n = 1). The estimated cumulative rate of incidence after MM was 5% at 5 years for any SPT, 3.7% for a second skin cancer, and 1.1% for a second solid tumor. Overall, the current cohort of MM patients was found to be at an increased risk for developing a subsequent melanoma (standardized incidence ratio [SIR], 4.5; 95% confidence interval [95% CI], 1.2-10.0) when compared with the general population. Older men (age > 50 years at the time of diagnosis of MM) were at an increased risk of developing subsequent bladder carcinoma (SIR, 6.4; 95% CI, 1.2-15.7).

CONCLUSIONS

Patients diagnosed with MM are at an increased risk of developing subsequent MM and bladder carcinoma. Issues to be addressed in future studies include interactions between environmental exposures and genetic susceptibility and the identification of individuals at increased risk.

Osteosarcoma and Ewing's sarcoma in a retinoblastoma patient

Retinoblastoma, though uncommon, frequently is associated with other second malignant neoplasms, especially bone sarcomas. These second neoplasms can occur in sporadic cases of retinoblastoma, though they more commonly are associated with genetic forms of the disease. This is the first known report of 2 histologically distinct bone sarcomas in a patient with retinoblastoma.

Immunohistochemical expression of retinoblastoma protein in cutaneous melanomas

Retinoblastoma protein (pRB) is the product of a tumour-suppressor gene (rb) mapped to chromosome 13q14. pRB acts as a control checkpoint at the G1 phase of the cell cycle, preventing cells from entering into the S phase. Mutational inactivation of both normal alleles leads to loss of pRB expression and the development of malignant neoplasms. Absence of pRB occurs in retinoblastomas, sarcomas and several other types of tumours. The potential role of pRB in the pathogenesis of cutaneous melanoma is unknown, and was the subject of this investigation. Formalin-fixed, paraffin-embedded sections of four cutaneous melanoma metastases, 17 primary invasive melanomas and 10 predominantly intradermal melanocytic naevi were studied. Monoclonal antibodies directed against pRB and Ki-67 antigen were used after microwave heating of sections to restore antigenicity. pRB was not detected in morphologically normal epidermal melanocytes. In five naevi, only scattered cells (1%) expressed pRB, whereas in the other five naevi, pRB expression was undetectable. In contrast, pRB was detected in all primary and metastatic melanomas (5-70% of cells). Expression was always localized to nuclei. Ki-67 expression was detected only in the melanomas, with both cellular staining and regional localization similar to that shown by pRB in 13 of the 20 melanomas studied with both antibodies. pRB appears to be expressed at higher levels in melanomas than in benign naevi. It therefore seems unlikely that loss of rb expression is an important factor in the pathogenesis of melanoma.

Familial cutaneous malignant melanoma and tumors of the nervous system. A hereditary cancer syndrome

BACKGROUND

Excessive risk of cutaneous melanoma as a second cancer has been associated with benign or malignant tumors of the nervous system. Cutaneous melanoma and nervous system tumors may independently aggregate in families. There are, however, no previous reports of increased likelihood of tumors of the nervous system in families of patients with cutaneous melanoma or--of cutaneous melanoma in families with tumors of the nervous system.

METHODS

The occurrence of nervous system tumors as second cancers was examined in a series of 904 patients with cutaneous melanoma and/or their family members.

RESULTS

Fifteen families with 17 members with cutaneous melanoma from this series had one or more additional relatives with tumors of the nervous system, including astrocytoma, medulloblastoma, glioblastoma multiforme, ependymoma, glioma, meningioma, and acoustic neurilemmoma. Another subgroup of 10 patients with cutaneous melanoma had either a meningioma (n = 9) or acoustic neurilemmoma (n = 1) as a second tumor. The pattern of atypical melanocytic nevi occurring in the majority (20/25) of cutaneous melanoma patients in our series and in additional first degree relatives of 9 of 11 of the affected families, has been previously associated with the Familial Atypical Multiple Mole-Melanoma syndrome.

CONCLUSIONS

This unusual familial and personal occurrence of tumors, showing differentiation toward tissues of the neural crest, neuroepithelium, and/or mesenchymal derivation, supports a putative association with a hereditary cancer susceptibility trait.

Retinoblastoma, melanoma and the atypical mole syndrome

Retinoblastoma patients and their relatives appear to have an increased risk of other cancers, especially melanoma, which represents 7% of second primaries in retinoblastoma survivors. Individuals belonging to families with the atypical mole syndrome (another family cancer syndrome with a genetic susceptibility to melanoma) have a recognizable phenotype, with many atypical melanocytic naevi. We report two families in which both retinoblastoma and melanoma occurred. It is of interest that in these families atypical melanocytic naevi were also demonstrated.

Exposure to ionizing radiation and risk of cutaneous malignant melanoma. Search for error and bias

In a 1984 case-control study of cutaneous malignant melanoma (CMM) among workers at the Lawrence Livermore National Laboratory, Austin and Reynolds found an association between reported employment in proximity to ionizing radiation and CMM (odds ratio (OR) = 5.4; 95% confidence interval (CI): 1.4, 20.7). But in a preliminary study in 1981, they found no association between individual radiation dosimetry readings and CMM. We reanalyzed the 1984 Austin-Reynolds case-control data to determine whether error or bias explain the inconsistency between reported employment in proximity to radiation and individual radiation dosimetry readings. Using individual radiation dosimetry readings, we developed an index of occupation-specific radiation. This index was associated with case status (OR = 10.8; 95% CI: 1.4, 85.1). No definitive evidence for influential matched sets, confounding, recall bias, or any other sources of bias was identified. These results suggest that the odds ratio for reported employment in proximity to radiation may be valid.

A commentary on an association of malignant melanoma with non-ultraviolet radiation exposure

There are direct and indirect studies that suggest that non-ultraviolet radiation may be associated with the increasing mortality and incidence of malignant melanoma of the skin. Tangential and supporting evidence for these associations are critically reviewed.