Conjunctival Metastasis from Pleural Mesothelioma.

PURPOSE OF THE STUDY To describe the ophthalmic and pathological features of a conjunctival tumour in a 76-year-old male with terminal pleural mesothelioma who developed a rapidly growing mass on the bulbar conjunctiva. PROCEDURES The patient presented with a rapidly growing, pink nodule on the right nasal bulbar conjunctiva. His past medical history included biopsy-confirmed pleural malignant mesothelioma treated unsuccessfully with chemoradiotherapy. By the time he presented with his ocular signs, the systemic management plan was palliative. An incisional biopsy of the conjunctival lesion was performed, stained with haematoxylin and eosin and exposed to immunohistochemistry. RESULTS The histology showed a solid and pseudo-papillary tumour. The tumour was positive for cytokeratin (AE1/AE3), calretinin, WT1 and mesothelin, confirming metastatic mesothelioma to the conjunctiva. CONCLUSIONS AND MESSAGE OF THE PAPER The clinical features mimicked metastatic carcinoma, and furthermore, the tumour's immunohistochemical positivity for cytokeratin could have led to an erroneous diagnosis of carcinoma rather than mesothelioma. The two key messages are (1) that metastatic mesothelioma can mimic metastatic carcinoma clinically and (2) that any cytokeratin-positive, rapidly growing conjunctival tumour with unusual morphology should be stained immunohistochemically with a mesothelioma panel to exclude metastatic mesothelioma.