A 60 year old man presents with an amelanotic mass in the posterior choroid.
The clinical diagnosis is that of malignant tumour ? melanoma ? metastasis.
A trans-vitreal aspirate is performed of the choroidal tumour.
Figure 1 and 2 show the H&E figures of pieces of solid tissue that were aspirated (cell block preparation).
Figure 3 is an AE1 AE3, Figure 4 is a prostate acid phosphatase and Figure 5 is a Melan A.
1. What do Figures 1 and 2 show?
2. Which additional investigations can be performed?
3. What is the likeliest diagnosis in this case?
1. Cohesive clusters of cells with an epithelioid morphology, bereft of melanin pigment, The nuclei are monotonous with some eosinophilc nucleoli. The cytoplasm has a bubbly appearance. Spindle cells do not feature.
2. Immunohistochemistry with melanocytic and epithelial markers.
3.The tumour is metastatic prostatic carcinoma to the choroid. The patient had a history of prostatic ductal adenocarcinoma, diagnosed on needle biopsies of the prostate.
Uveal metastasis from prostate carcinoma. De Potter P, Shields CL, Shields JA, Tardio DJ. Cancer. 1993 May 1;71(9):2791-6.