Pseudo-inflammatory manifestations of choroidal lymphoma resembling Vogt-Koyanagi-Harada disease: case report based on multimodal imaging

BACKGROUND: Hematologic malignancies occasionally cause serous retinal detachment (SRD); however, its pathogenesis remains unclear. Here we present the imaging characteristics of metastatic choroidal lymphoma masquerading as Vogt-Koyanagi-Harada (VKH) disease. CASE PRESENTATION: A 45-year-old Japanese woman was referred to our clinic because of bilateral SRD with blurred vision. Fluorescein angiography revealed multiple pinpoint leakage followed by pooling OU. Enhanced depth imaging optical coherence tomography showed marked choroidal thickening OU. Laser speckle flowgraphy detected choroidal circulation impairment OU. Although these results totally agreed with the inflammatory manifestations of acute VKH disease, indocyanine green angiography demonstrated various sizes of sharply marginated hypofluorescent lesions that seemed atypical for the finding of VKH disease, i.e., vaguely marginated hypofluorescent small dots. Cerebrospinal fluid pleocytosis was not detected. Blood tests revealed leukocytosis together with elevation of lactate dehydrogenase and soluble interleukin-2 receptor levels. Corticosteroid pulse therapy did not improve any ocular findings. Bone marrow biopsy was then performed, leading to a definite diagnosis of diffuse large B-cell lymphoma. After starting systemic chemotherapy, both SRD and choroidal thickening resolved rapidly with visual recovery. However, choroidal hypoperfusion persisted, which contrasted distinctly with the inflammatory pattern of VKH disease, i.e., the restoration of choroidal blood flow in parallel with normalization of choroidal thickness. CONCLUSIONS: Our detailed multimodal observations highlighted the differential imaging features of choroidal lymphoma despite close resemblance to VKH disease especially at the initial stage. Impaired circulation in the thickened choroid marked the pseudo-inflammatory pathogenesis of SRD due to choroidal involvement with neoplastic, but not inflammatory cells.