Malignant melanoma of the conjunctiva metastasizing to the submandibular gland: a case report and review of the literature.

Abstract

Background: Conjunctival malignant melanoma is an aggressive tumor with the potential for metastasis and death. It is rare in the black population because of the protective effect of melanin. Metastases are usually to regional lymph nodes, most commonly the preauricular nodes, deep cervical lymph nodes, and the salivary gland.

Case presentation: We described the case of a 41-year-old black African woman who presented to our ophthalmology clinic with a painless, right medial pigmented bulbar conjunctival swelling and right preauricular and submandibular swelling. Two years ago, she had similar swelling at the same location in the right eye. She subsequently underwent surgical excision under general anesthesia. Histology of both tissues showed proliferating malignant melanocytes that showed heavy pigmentation disposed of in solid nests, tongues, and sheets obscuring cellular details in these areas. Immunohistochemistry showed tumor cells to stain for HMB45 and Melan A. This led us to conclude that the tumor was a malignant melanoma. The patient died a year after making the diagnosis.

Conclusion: Conjunctival melanoma is a rare ocular malignancy that should be considered in cases of pigmented lesions of the eye, especially in people with dark pigmentation. Primary acquired melanosis with atypia or a nevus are known as preexisting melanocytic lesions from which conjunctival melanomas might develop. Metastases are often to preauricular and cervical lymph nodes as well as to the salivary gland. This demonstrates the significance of early presentation, thorough history taking, physical examination, and surgical excision for histopathology.