Statistics from Altmetric.com
A 24-year-old male patient presented to our specialty clinic with complaints of fullness in the inferior aspect of the left eye (figure 1A). The swelling was present from past 6 months and had increased to the present size. On palpation a postseptal mass was felt in the inferior orbit. The mass was painless in nature. On ocular examination, the visual acuity was 6/6 in both eyes. Pupillary reflexes were brisk. Fundus examination was normal, and no deficit of extraocular movements could be recorded. No other systemic abnormality was detected on general physical examination. The blood investigations revealed an increased erythrocyte sedimentation rate (ESR) (25 mm/hour). Chest X-ray and Mantoux test were done to rule out tuberculosis; however, these were found to be normal. Contrast-enhanced CT scan of chest and abdomen, serum antineutrophil cytoplasmic antibody (ANCA), antinuclear antibody (ANA), anti-ds DNA and rheumatoid factor levels were within normal limits. On ultrasonography of the left orbit, the echogenicity was consistent with that of a solid mass. A CT scan was done which revealed a non-specific mass in the inferior orbit (figure 1B,C). The extraocular muscles were found to be normal. An excision biopsy was done through inferior orbitotomy which revealed a cellular lesion with multiple plasma cells (figure 1D). Immunohistochemistry was positive for IgG4 (>40 plasma cells/hpf) (figure 1E). Serum IgG4 levels were found to be raised as well (2.13 g/dL). A diagnosis of IgG4-related disease (IgG4-RD) was made and the patient was started on oral steroids (methylprednisolone) in a dose of 0.6 mg/kg/day for a period of 4 weeks followed by a gradual tapering over a period of 3 months. At 6-month follow-up, the patient remains in remission (figure 1F).
IgG4-RD is an immune-mediated inflammatory condition which can affect various organs. The pathophysiology of this disease has not been completely understood. The diagnosis of IgG4-RD requires a combination of clinical examination, imaging, histological and serological analyses. Orbit is a common site for involvement in IgG4‐RD, and it was the first extrapancreatic site to be reported.1 Orbital IgG4-RD (IgG4ROD) is characterised by tumefactive orbital lesions showing polyclonal IgG4 plasma cell rich lympho-plasmocytic infiltrate on histopathology with or without raised serum IgG4 levels. It probably results from a dysregulated immune response to antigens that may involve several organs. In cases of IgG4ROD, 62% have bilateral lesions, 69% have lacrimal gland involvement, out of which 48% have bilateral lacrimal gland involvement.2 Within the orbit, the lacrimal gland is the most commonly affected structure, though it can affect any orbital structure. To the best of our knowledge, this is the first case of IgG4ROD presenting as an isolated orbital mass. Extraorbital involvement occurs in 22%–71% cases of IgG4ROD mostly to salivary glands and lymphnodes.1 Some authors recommend 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) to detect extraorbital involvement. There was no extraorbital involvement in current case. Glucocorticoids are the first line agents in the treatment of this disease entity. Rituximab (anti-CD20 monoclonal antibody) has emerged as a promising treatment option for IgG4ROD.3
Orbital IgG4-related disease may present as an isolated orbital mass.
A detailed work-up including histopathology is required to establish the diagnosis.
Oral steroids are an effective treatment modality.
Contributors NG, AS and MSB contributed to diagnosis, workup, writing the manuscript and performing critical revision. RM is the overall responsible for the presentation, contributed to diagnosis and performed critical revision of the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
Patient consent for publication Obtained.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.