Diplopia and Vision Loss Associated With Presumed Systemic Lymphohistiocytic Disease: A Case Report.

Systemic lymphohistiocytic infiltration is a rare peculiar condition that can raise the possibility of more specific entities such as autoimmune disease, drug interaction, viral or mycobacterial infection, or malignancy. A hyper-inflammatory state can ensue leading to multi-organ failure. We report the case of a 42-year-old Jordanian male with a past history of moderate Covid-19 infection presenting with binocular diplopia and acute loss of vision in the left eye. Ophthalmic evaluation revealed limitation of extraocular motility in all directions of gaze in the left eye and a visual acuity of 6/30 with a sluggish pupil. Orbital imaging revealed a 10 mm mass at the orbital apex suspicious of malignant metastasis. A positron emission tomography CT scan showed significant pleural thickening and was highly suggestive of metastatic mesothelioma seeding to the orbit, liver, and bone. A CT guided biopsy of the right lung was negative for malignancy but had features of lymphohistiocytic pleuritis. The patient dramatically succumbed to respiratory and renal failure. Systemic lymphohistiocytic infiltration is an aggressive benign inflammatory process that may masquerade as malignancy and raise the possibility of past viral infections, autoimmune diseases, or cancer. A high index of suspicion and a multidisciplinary approach is warranted. In this particular devastating instance, a diagnostic dilemma presented to the eye clinic with diplopia, loss of vision, and an orbital mass, culminating in rapid onset respiratory and renal failure and death.