ABSTRACT

Orbital involvement in systemic sarcoidosis is a rare condition. We report a case of orbital sarcoidosis with bilaterally huge lacrimal gland involvement as the initial manifestation of systemic sarcoidosis. A 20-year-old woman admitted the ophthalmology department with progressive bilateral upper eyelid swelling for 6 months. The only pathologic finding was the presence of bilateral, symmetrical, solid, lobular masses at the lateral upper eyelids at the location of lacrimal glands. On systemic examination, bilateral parotid and submandibular glands appeared swollen. Magnetic resonance imaging of the orbit revealed bilateral symmetrical diffuse enlargement of the lacrimal glands with maximum and minimum thickness of 11 mm and 7 mm, respectively. The biopsy findings were compatible with sarcoidosis. Although lacrimal gland involvement has been reported in different studies, we for the first time report an unusual case with bilateral diffuse huge lacrimal gland involvement. Normal lacrimal gland thickness is approximately 4-5 mm in magnetic resonance imaging, while our case had bilateral diffuse enlargement of lacrimal glands, which showed maximum and minimum thickness of 11 mm and 7 mm, respectively. Although orbital involvement is uncommon in sarcoidosis, it should be remembered in the differential diagnosis of orbital masses.

Introduction

Sarcoidosis is an idiopathic, multisystem disorder that can affect any organ system and is mainly characterised by pulmonary, dermatologic, and ocular involvement. Its pathological hallmark is non-caseating granulomatous inflammation. Ocular involvement has been reported by different studies at a rate of 25-60%.1,2 Although anterior uveitis is the most common manifestation of ocular sarcoidosis, any orbital structure can be involved. Lacrimal gland involvement is the most common form of orbital sarcoidosis.1,3 We present a case of orbital sarcoidosis with bilateral enlargement of the lacrimal glands with eyelid and anterior orbital involvement as the initial manifestation of systemic sarcoidosis.

Discussion

Ocular adnexal sarcoidosis usually presents as a local mass. We present an unusual bilateral enlargement of the lacrimal glands and involvement of the anterior orbit and eyelids due to orbital sarcoidosis as the initial manifestation of systemic sarcoidosis.

Lacrimal glands are the most commonly involved structures of the orbit in orbital sarcoidosis.3,4,5 The prevalence of lacrimal gland involvement varies across studies due to varying diagnostic criteria. Two large studies reported lacrimal gland involvement at rates of 7% and 15.8%.2,6 These studies based the diagnosis of orbital sarcoidosis on lacrimal gland enlargement and the presence of dry eye symptoms. However, sarcoidosis is a pathologic diagnosis, so a biopsy is recommended for a definitive diagnosis.

Because of the inflammatory nature of sarcoidosis, orbital symptoms usually mimic other inflammatory diseases that involve orbital structures. Sjögren’s syndrome, tuberculosis, lymphoma and immunoglobulin  G4 (IgG4)-related Mikulicz’s disease are the main pathologies that should be considered in the differential diagnosis of sarcoidosis. Although these diseases can be seen at any age, Sjögren’s syndrome and tuberculosis are the primary diseases for the differential diagnosis of sarcoidosis in younger patients. These diseases can cause bilateral involvement and are usually characterised by painless enlargement of lacrimal glands for more than one month. Although clinical findings and imaging tests can help guide clinicians, a biopsy is required for all patients with orbital masses of unknown origin.

The characteristic histological feature of sarcoidosis is non-caseating granulomas consisting of epithelioid histiocytes and lymphocytes. Multinucleated giant cells are frequently seen. Although tuberculosis is also characterised by chronic granulomatous inflammation, in tuberculosis the granulomas tend to be coalescent with necrosis. The presence of atypical lymphocytes in lymphoma, IgG4-positive plasma cells in IgG4-related Mikulicz’s disease, periductal and perivascular inflammation of lymphocytes and intralobular fibrosis in Sjögren’s syndrome are the main factors that aid in the differential diagnosis of sarcoidosis.7

This case is important because the first symptom of systemic sarcoidosis in this case was diffuse enlargement of the lacrimal glands with eyelid and anterior orbital involvement. MRI reveals normal lacrimal gland thickness to be approximately 4-5 mm,8 whereas our case had bilateral diffuse enlargement of the lacrimal glands, which possessed maximum and minimum thicknesses of 11 mm and 7 mm, respectively.

Although orbital involvement is uncommon in sarcoidosis, it should be considered in the differential diagnosis of orbital masses. This case is striking compared to the previous case reports in the literature with respect to bilateral and substantially larger lacrimal gland involvement. The diagnosis of sarcoidosis should be made by clinical, laboratory, and radiological findings and confirmed by histopathological examination. It is necessary to screen all systems, and treatment decisions should be based on the presence of the organ and system involvement.