Congenital Self-healing Reticulohistiocytosis: An Underreported Entity
Langerhans cell histiocytosis (LCH), also known as histiocytosis X, is a group of rare disorders characterized by the continuous replication of a particular white blood cell called Langerhans cells. These cells are derived from the bone marrow and are found in the epidermis, playing a large role in immune surveillance and the elimination of foreign substances from the body. Additionally, Langerhans cells are capable of migrating from the skin to lymph nodes, and in LCH, these cells begin to congregate on the bone, particularly in the head and neck region, causing a multitude of problems. Langerhans cell histiocytosis is classified into 4 variants: congenital self-healing reticulohistiocytosis (CSHR)(also known as Hashimoto-Pritzker disease), Letterer-Siwe disease, Hand-Schüller-Christian disease, and eosinophilic granuloma. Despite various clinical presentations and severity, all subtypes are pathologically caused by the proliferation of the Langerhans cell.
Practice Points
- Langerhans cell histiocytosis (LCH) is believed to occur in 1:200,000 children and tends to be underdiagnosed, as some patients may have no symptoms while others have symptoms that are misdiagnosed as other conditions.
- Patients with LCH usually should have long-term follow-up care to detect progression or complications of the disease or treatment.
Conclusion
The actual incidence of CSHR may be notably underreported due to its spontaneous regression and low rate of clinical recognition. A subtype of LCH, CSHR is a diagnosis of exclusion. Although CSHR generally follows a benign clinical course, a thorough workup and evaluation for systemic disease with close follow-up is recommended after diagnosis due to the potential of LCH to involve multiple organs and to relapse at a later date after apparent regression.
