Objective: The differential diagnosis between retinal detachment and melanoma metastatic to the vitreous can be challenging, both clinically and cytologically. We demonstrate the diagnostic features and pitfalls of the cytological assessment. Study Design: A case of a metastatic melanoma to the vitreous is compared to a case of retinal detachment initially suspected as melanoma metastasis. Case 1 was a 54-year-old patient with a vague history of pigmented lesions 20 years previously and a current presentation of a visual defect. Case 2 was a 68-year-old patient with a history of melanoma and a presentation of floaters and flashing lights. Results: The vitreous fluid of case 1 contained atypical, pigment-laden cells positive for HMB-45 and assessed as melanoma. On enucleation, a melanoma metastatic to the vitreous was diagnosed. The vitreous fluid of case 2 revealed atypical cells containing pigment granules. The cells were negative for melanocytic markers, while the granules stained positive for melanin. Macrophage marker CD163 was positive in all cells. The interpretation was one of macrophages reactive to the retinal detachment. Conclusion: Melanin-laden macrophages can mimic melanoma cells. This needs to be considered in the differential diagnosis. Additional stains can help the distinction.

Gündüz K, Shields JA, Shields CL, Eagle RC Jr: Cutaneous melanoma metastatic to the vitreous cavity. Ophthalmology 1998;105:600-605.
Rosenberg C, Finger PT: Cutaneous malignant melanoma meta-static to the eye, lids, and orbit. Surv Ophthalmol 2008;53:187-202.
Zografos L, Ducrey N, Beati D, Schalenbourg A, Spahn B, Balmer A, Othenin-Girard CB, Chamot L, Egger E: Metastatic melanoma in the eye and orbit. Ophthalmology 2003;110:2245-2256.
Zografos L, Mirimanoff RO, Angeletti CA, Frosini R, Beati D, Schalenbourg A, Chamot L: Systemic melanoma metastatic to the retina and vitreous. Ophthalmologica 2004;218:424-433.
Ramaesh K, Marshall JW, Wharton SB, Dhillon B: Intraocular metastases of cutaneous malignant melanoma: a case report and review of the literature. Eye 1999;13:247-250.
Cranmer LD, Trevor KT, Bandlamuri S, Hersh E: Rodent models of brain metastasis in melanoma. Melanoma Res 2005;15:325-356.
Prabhakaran VC, Font RL: Cutaneous malignant melanoma metastatic to the vitreous. Retina 2007;27:379-381.
de Bustros S, Augsburger JJ, Shields JA, Shakin EP, Pryor CC 2nd: Intraocular metastases from cutaneous malignant melanoma. Arch Ophthalmol 1985;103:937-940.
Robertson DM, Wilkinson CP, Murray JL, Gordy DD: Metastatic tumor to the retina and vitreous cavity from primary melanoma of the skin. Treatment with systemic and subconjunctival chemotherapy. Ophthalmology 1981;88:1296-1301.
Cole EL, Zakov ZN, Meisler DM, Tuthill RJ, McMahon JT: Cutaneous malignant melanoma metastatic to the vitreous. Arch Ophthalmol 1986;104:98-101.
Eide N, Syrdalen P: Intraocular metastasis from cutaneous malignant melanoma. Acta Ophthalmol 1990;68:102-106.
Khurana RN, Tran VT, Rao NA: Metastatic cutaneous melanoma involving the retina and vitreous. Arch Ophthalmol 2007;125:1296-1297.
Bowman CB, Guber D, Brown CH, Curtin VT: Cutaneous malignant melanoma with diffuse intraocular metastases. Arch Ophthalmol 1994;112:1213-1216.
Krema H, Fernandes B, Simpson R, Lutchman C, Yucel Y: Diffuse metastatic melanoma to the retina: a clinicopathologic report. Can J Ophthalmol 2013;48:e20-e21.
Ordóñez NG: Value of melanocytic-associated immunohistochemical markers in the diagnosis of malignant melanoma: a review and update. Hum Pathol 2014;45:191-205.
Browning S: Retinal detachment. Optician 2010;240:22-23.
Gibran SK, Kapoor KG: Management of exudative retinal detachment in choroidal melanoma. Clin Experiment Ophthalmol 2009;37:654-659.
Fernandez-Bueno I, Pastor JC, Gayoso MJ, Alcalde I, Garcia MT: Müller and macrophage-like cell interactions in organotypic culture of porcine neuroretina. Mol Vis 2008;14:2148-2156.
Root T: Beginner's Guide to the Retina. OphthoBook. Root Eye Network, n.d. http://www.ophthobook.com/chapters/retina (accessed October 3, 2014).
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