MULTIMODAL IMAGING AND HISTOLOGIC CORRELATION OF ISOLATED METASTASIS OF PROSTATE ADENOCARCINOMA TO THE CHOROID.

Purpose: To provide correlative clinical-multimodal imaging-histopathologic findings of isolated prostatic choroidal metastasis.

Methods: Ophthalmologic examination, fluorescein angiogram, spectral-domain optical coherence tomography, fundus autofluorescence, computerized tomography, magnetic resonance imaging, positive emission tomography, CSF analysis, serologies, tissue pathology with immunohistochemistry, and examination of relevant literature.

Results: A 76-year-old man with a history of prostate adenocarcinoma was referred for 2 months of unilateral blurry vision. Fundus examination revealed elevated deep orange choroidal lesions in the macula with overlying retinal pigment epithelium mottling and subretinal fluid. Fluorescein angiogram demonstrated alternating areas of hypofluorescence and hyperfluorescence (staining) without leakage. Optical coherence tomography revealed dome-shaped and lumpy choroidal lesions with surrounding undulating "lumpy bumpy" and "rippled/seasick" patterns. Workup for a primary or additional metastatic lesion including computerized tomography of head/chest/abdomen/pelvis, lumbar puncture, magnetic resonance imaging brain, and whole-body positive emission tomography scan was negative. Full-thickness excisional chorioretinal biopsy was obtained through pars plana vitrectomy with diathermy and vertical scissors. Histologic examination revealed adenocarcinoma with weak positive staining for prostate specific antigen, moderate positive staining for P501S (prostein), and strong positive staining for prostatic acid phosphatase, consistent with metastasis from a prostate primary. Treatment consisted of local radiation with regression of the metastatic tumor. The patient is also on concomitant androgen deprivation treatment because there is a very high incidence of systemic recurrence due to hematogenous involvement. The patient's vision has continued to improve 6 months past treatment.

Conclusion: The authors present a unique case to highlight the multimodal imaging and histology of a rare presentation of biopsy-proven, isolated metastasis of prostate adenocarcinoma to the choroid. Systemic workup is required, and if unrevealing of a primary or metastatic lesion, full-thickness chorioretinal biopsy and histopathology can provide a definitive diagnosis, allowing optimal treatment. Chorioretinal biopsy is a useful technique and may allow for visual preservation while also giving superior histologic quality.