[Clinical and pathological features of 26 cases of conjunctival melanoma]

To improve the knowledge of clinical and pathological features of conjunctival melanoma, in order to have an early diagnosis and treatment.

Retrospective cases analysis. The clinical and pathological features of 26 cases of conjunctival melanoma were analyzed. These cases were treated from May in 1985 to June in 2007 in Tianjin Eye Hospital. Routine pathological examination and immunohistochemical staining of S-100 and HMB-45 were performed.

The mean age was 53.4 years and ranging from 30.0 - 83.0 years. In these cases, 11 cases arose from primary acquired melanosis (PAM), 8 cases from conjunctival nevi or melanocytoma and 7 cases occurred de novo. Fourteen cases involved tarsal and bulbar conjunctiva, 6 cases involved bulbar conjunctiva only, 4 cases involved tarsal conjunctiva only and 2 cases were located at the limbus. Twenty two cases were epitheloid-cell-type melanoma, 4 cases were mixed-cell-type melanoma. There were 3 amelanotic melanomas, the tumor cells were positively stained with S-100 and HMB-45. The follow-up period was 1-18 years postoperatively in 14 cases. Among them, 12 cases showed 1-3 recurrences, 3 cases with preauricular lymph node metastasize, 1 cases with preauricular and submandibular lymph nodes metastasize; and 4 cases died from systematic extension or hepatic metastasis.

Conjunctival melanoma mainly arises from malignant transformation of PAM or conjunctival nevi and consists of epitheloid melanotic tumor cells. The neighbor intraepithelial invasion and recurrence are common, particularly in diffuse type of tumors or tumors arising from PAM.