Case of Rapidly Expanding Conjunctival Malignant Melanoma Initially from Primary Acquired Melanosis Diagnosed 14 Years Earlier

Abstract

Primary acquired melanosis (PAM) of the conjunctiva is a potentially serious melanocytic lesion that can lead to the development of a melanoma. A 60-year-old woman noticed pigmentation of the conjunctiva of her left eye for more than 10 years. She underwent excisional biopsy combined with cryotherapy and was diagnosed with PAM without atypia by intraoperative consultation. She was followed for 7 years, and no changes were observed. Fourteen years after the initial biopsy, she noted a growing conjunctival tumor, and a melanoma was suspected. She underwent orbital exenteration and skin grafting procedures. Histopathological examination of the specimen led to a diagnosis of conjunctival malignant melanoma. Re-examination of the initial biopsy specimen revealed that there was a proliferation of melanocytes that partially expanded over the basal layer of the conjunctiva which had been diagnosed as PAM with moderate atypia. We conclude that this case of conjunctival PAM had progressed to a conjunctival malignant melanoma after 14 years. Pathological evaluation of intraepithelial lesions has its limitations; thus, cases of PAM, even in the absence of obvious atypia, require careful follow-up.

Keywords:

• primary acquired melanosis
• conjunctival malignant melanoma
• malignant melanoma
• conjunctival melanoma
• conjunctival tumor

Abbreviations

PAM, primary acquired melanosis; BCVA, best-corrected visual acuity; C-MIN, conjunctival melanocytic intraepithelial neoplasia.

Data Sharing Statement

All data supporting the conclusions of this article are included in this published article.

Consent for Publication

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor of this journal.

Acknowledgment

Professor Duco Hamasaki of the Bascom Palmer Eye Institute for discussions and manuscript revision.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

Dr Chie Sotozono reports grants from Japan Agency for Medical Research and Development (AMED), Ministry of Health, Labour and Welfare, Japan, Japanese Ministry of Education, Culture, Sports, Science and Technology, and a Research Grant, outside the submitted work. The authors declare that they have no other competing interests.

Additional information

Funding

No funding or grant support.