BackgroundLigneous conjunctivitis (LC) is a rare inflammatory lesion of the conjunctiva with an unknown etiology. It is easily confused with conjunctiva lymphoma or other diseases in clinical diagnosis, and the lesion is very difficult to treat.Case presentationWe presented a 41-year-old female patient presented with bilateral conjunctival masses for more than six months. The patient had no contributory history of ocular trauma, family history of tumor and drug allergy. Taking the patient's clinical and pathological features together, we considered this was a case of IgG4 + LC. Completely surgical resection combined with local glucocorticoid treatment might be effective.ConclusionsThis is a very rare case report of immunoglobulin G4 positive LC with only one published case in literature. The typical manifestations of LC are with the appearance of a hard, fibrin-rich, woody pseudomembranous lesion. A large number of lymphocyte and plasma cell are infiltrated in the pathological tissue. Inflammation of LC may cause immune abnormalities, resulting in IgG4 increasing.