Bone metastasis in a case of primary acquired melanosis with atypia resulting from conjunctiva melanoma

A 66-year-old woman presented to a tertiary referral centre with a diagnosis of limbal stem cell deficiency secondary to multiple treatments for primary acquired melanosis (PAM) by her referring ophthalmologists. She was known with primary acquired melanosis with severe atypia of the right eye which had been treated with several excisions, cryotherapy and topical chemotherapy. She had PAM over 360° of alternating intensity. Throughout the follow-up period, she developed a cataract and subsequent a retinal detachment for which she underwent a phacovitrectomy on the right eye. There was no nodule present nor did the routine lymph nodes inspection show any enlargement. No abnormalities were observed on intranasal examination. Seven years after the last excision, a metastasis to the spine (Th3) was diagnosed. A complete systemic work-up and a pathological examination did not show any alternative primary melanoma in the body. The original histological material was reviewed again by an ophthalmopathologist. After a new round of stains and immunohistochemistry, the presence of atypical melanocytes in both the epithelium and stroma were found in a scar region leading to a renewed conclusion that the PAM in question was actually the primary melanoma.