Nonosseous Periocular Manifestations of Langerhans Cell Histiocytosis: A Case Report and Systematic Review

Purpose: Langerhans cell histiocytosis (LCH) is a disorder of dendritic cell proliferation that typically involves bone. It can be diagnostically challenging when LCH presents without bony involvement, leading to delays in diagnosis and treatment. In this study, the periocular manifestations of LCH in cases where the underlying orbital bones are not involved are described through a systematic review. Methods: A systematic review of the literature was performed to capture all cases of LCH that involved the periocular region but not the underlying orbital bones. These included LCH cases that involved the periocular skin, the ocular surface, and the orbital tissue. The authors also highlight an additional case where LCH presented with periocular edema and multifocal, nodular conjunctival lesions. Result: This review illustrates that LCH rarely presents with periocular infiltration without orbital bone involvement. In these atypical cases, LCH can present as an eyelid mass, a chalazion-like lesion, generalized periocular swelling, ocular surface lesions, or infiltration of any orbital structure. Ocular surface LCH has a higher rate of recurrence than other periocular LCH. Orbital LCH can involve any tissue including extraocular muscles, the lacrimal gland, or indistinct areas within the orbit. Conclusions: LCH is a clinicopathologic diagnosis. Although most cases involve the bone, any soft tissue can be involved. Biopsy is required to confirm the diagnosis of this heterogeneous disease. Langerhans cell histiocytosis can present in the periocular area without involving orbital bone. There are several typical patterns of tissue involvement; however, any soft tissue can ultimately be affected. Clinicians should be aware of the findings in these rare cases.