The Granulomas of Orbital Sarcoidosis Often Show Foci of Necrosis: A Retrospective Observational Study.

Purpose: To characterize the frequency and extent of necrosis within granulomas among patients diagnosed with orbital sarcoidosis on biopsy.

Methods: A retrospective review was conducted of patients diagnosed with orbital sarcoidosis at a single institution from 2018 to 2024. Histopathology slides were re-reviewed for evidence of any necrosis or infection. Demographic, laboratory, histopathologic, and radiographic data were gathered for these patients. All findings were presented using descriptive statistics.

Results: There were 19 total cases of orbital sarcoidosis in the study timeframe. The majority were female (15, 78.9%) with a median age of 49 (range: 11-85) presenting with a unilateral, mass-occupying orbital lesion (n = 16, 84.2%). The lacrimal gland and orbital fibroadipose tissue were the most frequently involved and biopsied. Biopsies from 13 patients (68.4%) had granulomas containing varying amounts of necrosis on histopathology on retrospective review. No fungal or acid-fast microorganisms were detected with special stains; a subset of patients had additional molecular genetic-based microbiologic studies which were also unrevealing.

Conclusions: Although the histopathology of sarcoidosis is classically described as a "non-necrotizing (noncaseating) granulomas," granulomas with varying extents of necrosis are more frequently seen in orbital sarcoidosis than previously recognized, or than reported in biopsies from patients with sarcoidosis at other anatomic sites. The presence of necrosis within sarcoidal granulomas should not exclude a diagnosis of sarcoidosis at this site, given that infection is adequately excluded.