Clinicopathological features differentiating Castleman Disease from IgG4-related ophthalmic disease, a 10 years retrospective study.

PURPOSE: This study compared two rare diseases that present with enlarged lacrimal glands and analyzed their clinical features, among others, for identification. METHODS: Setting - A single-center retrospective study. PATIENT OR STUDY POPULATION: Patients treated at our center from 2013 to 2023 with pathologically diagnosed IgG4-ROD (n = 31, 42 eyes) and CD (n = 5, 5 eyes). INTERVENTION OR OBSERVATION PROCEDURES: No interventions administered. MAIN OUTCOME MEASURES: The analysis included patient demographics, laboratory tests, histopathological tests, imaging studies, treatment, and outcomes. Data collection involved visualizing medical records. RESULTS: The lacrimal glands/eyelid soft tissues and extraocular muscles of the IgG4-ROD group were affected. Histopathological examination showed lymphoid proliferation in both groups had lymphocyte hyperplasia, and the pathological IgG4+/IgG+ ratio in the IgG4-ROD group was higher than that in the CD group (P = 0.0057), which was more than 40%. IgG4-ROD exhibited significantly higher MASSON positivity than CD (78.1% vs. 33.3%, P = 0.0466). CD lesions exhibited a 50% reduction in Ki-67 proliferative activity relative to IgG4-ROD (P = 0.0349). Bone destruction was identified in 20% of CD versus none in IgG4-ROD (P = 0.024). Conversely, fibrotic imaging features demonstrated a significantly higher prevalence in IgG4-ROD (40%) compared to CD (P = 0.0103). CONCLUSIONS: Significant differences in pathology and imaging exist between IgG4-ROD and CD. IgG4-ROD is characterized by an IgG4+/IgG+ plasma cell ratio exceeding 40% and extensive fibrosis. Imaging predominantly reveals nondestructive fibrotic foci, reflecting the chronic inflammatory fibroproliferative nature of the disease. Conversely, CD exhibits higher local invasiveness and lower cellular proliferative activity.