Children with malignant melanoma: a single center experience from Turkey

Treatment response and recurrence of conjunctival melanoma with orbital invasion treated with immune checkpoint inhibitors: case report and literature review

INTRODUCTION

Conjunctival melanoma (CM) has genetic characteristics that are similar to primary cutaneous melanoma (PCM). The management of advanced CM with orbital metastasis was limited until the adoption of novel immunotherapy agents that significantly improved the survival of metastatic PCM.

PURPOSE

To review and compare the immune checkpoint inhibitor (ICI) treatment response in cases reported in the English literature with orbital involvement secondary to CM versus PCM. In addition, we report a case of local recurrence of CM in a young female after successful treatment with ICI.

METHODS

In addition to reviewing the chart of one patient who presented to our clinic, we conducted a comprehensive literature review to identify CM cases and cases with orbital metastasis secondary to advanced CM and PCM. Outcomes included patient demographics, response to ICI, and associated adverse effects.

RESULTS

There were ten cases with orbital involvement, four were secondary to CM, and six were metastasis from PCM. Orbital metastasis from PCM regressed following treatment with ICI agents, whereas those secondary to CM resolved completely. There were 19 cases of CM without orbital invasion. Of the 29 cases identified, complete resolution of ocular melanoma was achieved in 15 patients, representing 52% of the cases collectively, and none of them reported recurrence except in our case.

CONCLUSION

CM with orbital invasion responds well to ICIs, with manageable toxic effects. Despite the complete resolution, close observation is needed as the recurrence risk remains.

[Reed nevus and cutaneous melanoma in children: an immunohistochemical study]

Certain difficulties arise in the differential diagnosis between Reed nevus that is common in children and adolescents and cutaneous melanoma that is extremely rare in patients of this age group. In addition to the classical histological examination, an immunohistochemical test for marker proteins is carried out to improve the accuracy of the diagnosis of pigmented skin neoplasms.

OBJECTIVE

To evaluate the suitability of a set of proteins (cyclin D1, p16^INK4a, and HLA class I antigens) in the differential diagnosis of Reed nevus and cutaneous melanoma in children and adolescents.

MATERIAL AND METHODS

Three samples of pigmented skin neoplasms were taken during surgical treatment in patients at the Blokhin National Medical Research Center of Oncology: two samples of Reed nevus (from a 9-year-old girl and a 15-year-old boy) and a sample of cutaneous melanoma that had developed in an 8-year-old boy. The materials were presented by paraffin blocks. Immunohistochemical staining was performed using antibodies against cyclin D1, p16^INK4a, and HLA class I antigens.

RESULTS

Differences were found between nevus and melanoma in the expression of all three markers. Thus, the nuclear expression of cyclin D1, a proliferation activator, occurred in some cells in the nevus samples and in the vast majority of cells in the melanoma samples. The nuclear expression of the cell cycle inhibitor p16^INK4a was dramatically reduced in melanoma compared to nevus. HLA class I antigens were detected on the surface of individual nevus cells, but were completely absent on the membranes and in the cytoplasm of melanoma cells, which could promote the evasion of this tumor from the body's immunological supervision.

CONCLUSION

Immunohistochemical test for the proteins cyclin D1, p16^INK4a, and HLA class 1 antigens is a promising approach to differentially diagnosing between Reed nevus and cutaneous melanoma in children and adolescents.