Acute Lymphoblastic Leukemia Masquerading as Vogt-koyanagi-harada Disease

Purpose: To report a case of Acute Lymphoblastic Leukemia masquerading as Vogt-Koyanagi-Harada disease. Case Report: A 61-year-old man presented with decreased visual acuity in both eyes. Optical coherence tomography showed bilateral exudative retinal detachment and uorescein angiography pinpoint leakage. The patient was diagnosed with Vogt-Koyanagi-Harada disease. Blood analysis revealed increased percentage of blast cells (69%) and bone marrow biopsy conrmed the diagnosis of acute B cell lymphoblastic leukemia. He received chemotherapy treatment with multiple drugs including asparaginase, which caused hepatic disease and patient’s death despite ocular ndings improvement. Conclusions: Acute lymphoblastic leukemia may present as a bilateral exudative retinal detachment and can mimic VKH. Therefore, clinicians should take into consideration the possibility of leukemia in such patients. This fact stresses out the importance of multidisciplinary management of uveitis conditions.


Introduction
Leukemias are a group of haematopoietic stem cells malignancies involving abnormal increase of white blood cells. We can classify them depending on the line of proliferation into lymphoid or myeloid leukemia and between acute and chronic type. Ocular involvement in leukemias has been reported in a large percentage of cases, between 9 and 90% depending on the study. Any ocular structure might be involved and the in ltration of the eye is the third most frequent extramedullar location after meningeal and testicular involvement. Although ndings diverge from retinal haemorrhages and in ltrates to optic nerve or orbital in ltration, exudative retinal detachment is a very rare ocular nding in leukemia and has only been described in a few cases.
In this paper we report a case of acute lymphocytic leukemia presenting with bilateral exudative retinal detachment simulating probable acute Vogt-Koyanagi-Harada (VKH) disease.

Case Report
A 61-year-old man presented with gradual visual loss in both eyes over 1 week. The decline in left eye visual acuity had begun accompanied by ashes. He had no medical history of previous ocular trauma or surgery, and the clinical interview did not reveal any headache or tinnitus symptoms. He suffered from arterial hypertension and chronic rhinitis, and had recently been taking Cetirizine and inhaled corticosteroids for this reason. His best corrected visual acuities were 20/50 and 20/40 in the right and left eyes, respectively. There was no anterior chamber reaction or vitreous cells in either eye. Intraocular pressure was 12 mmHg both eyes. Fundus examination and Optical coherence tomography (OCT) showed bilateral exudative retinal detachment in both eyes, and 2 cotton wool spots in the right eye Fluorescence angiography (FA) showed multiple hyper uorescent pinpoint leakage in posterior pole and arround optic disc without disc leakage, and diffuse hyper uorescence in the area of cotton wool spots in the right eye (Fig. 3).
Although clinical diagnosis of bilateral central serous chorioretinopathy was rst considered, incomplete Vogt-Koyanagi-Harada disease was nally assumed. The patient received an intravenous 500 mg metilprednisolone pulse and a complete blood analysis was seeked. The following day the blood analysis results were received and showed decreased platelet counts (10,000/µL), normal white blood cell counts (15,000/µL) with an abnormally increased percentage of blast cells (69%) presenting with cup-like nuclear invagination. Hence, the patient was admitted in the hematology department where a bone marrow biopsy revealed presence of 91% of blast cells, some of them with their nucleus indented, and con rmed the diagnosis of acute B cell lymphoblastic leukemia. The patient received induction chemotherapy consisting of vincristine, prednisone, daunorubicin, asparaginase and rituximab. One week later, his best corrected visual acuities were 20/63 and 20/50, serous retinal detachments were nearly absorbed (Fig. 4), but newly developed cotton wool spots near the optic disc appeared. Despite blood cell counts improved after chemotherapy, the patient died of hepatic veno-occlusive disease 2 months after starting treatment which was attributed to asparaginase.

Discussion
In leukemic patients, visual loss was rst described by Zimmerman in 1964 (1).
The typical ocular manifestations of leukemia are most commonly due to direct tissue in ltration with leukemic cells, but other hematologic mechanisms such as anemia and hyperviscosity may play a role.
The mechanism behind serous retinal detachments associated with leukemia is less well understood.
Proposed mechanisms include abnormal choroidal perfusion and/or damage to the outer blood-retinal barrier, along with neoplastic choroidal in ltration, localized choroidal hypoxia, or alterations of local oncotic and/or hydrostatic forces. Additionally, choroidal hypoxia may lead to dysfunction of retinal pigment epithelium with subsequent accumulation of subretinal uid. This may appear on uorescein angiography as pinpoint areas of hyper uoresence in the early phase (13). Our patient presented Funduscopy, OCT and and FA ndings that resembled a VKH syndrome. However, assessing the clinical examinations images retrospectively some features were not typical of VKH. Firstly, prodromal symptoms of headache and tinnitus and anterior uveitis were absent in our case, which are frequently seen in VKH disease (14). Additionally, FAG did not show hyper uorescence of optic disks, a typical nding of VKH.
Cotton wool spots were observed in our patient, an abnormality that has not been described in VKH. Moreover OCT did not reveal bacillary detachments, usually observed in VKH disease (15).
Masquerade syndromes are ocular clinical pictures that resemble uveitic diseases.A typical example is vitreoretinal lymphoma, which may be associated to central nervous system lymphoma in a high proportion of patients (16)(17).
Our patient presented with signs of VKH syndrome: exudative bilateral retinal detachments and pint point leakage in FAG. However, as mentioned above, other signs were lacking.
When managing atypical cases of uveitis masquerade syndromes have to be considered. A proper diagnosis by the ophthalmologist is crucial in order to initiate a prompt therapyfor these frequently fatal diseases.