Cytology of metastatic cutaneous melanoma to the vitreous and retina

Purpose: The authors report one patient with definitive and one patient with presumed metastatic cutaneous malignant melanoma to the vitreous and retina diagnosed by cytologic evaluation of the vitreous and subretinal fluid. Methods: A diagnostic vitrectomy was performed on two patients with atypical vitreous and retinal infiltrates. Additionally, subretinal fluid was obtained from the second patient, The specimens were processed for cytologic examination. The cytology specimens were compared with previously excised cutaneous melanomas from the patients. Results: Examination results showed cells in the vitreous with high nuclear-to-cytoplasm ratios, coarse chromatin, and intracytoplasmic melanin pigment granules. The cytologic features were compared with the cutaneous malignant melanoma, and a diagnosis of metastatic melanoma was made. One patient eventually required enucleation, and the metastatic tumor in the other patient was controlled by local irradiation. Conclusions: Cytologic evaluation of the vitreous and subretinal fluid is helpful in establishing a diagnosis in patients with metastatic cutaneous melanoma to the vitreous and retina.