Langerhans cell histiocytosis (LCH) usually presents with a skinrash or painful bone lesion. Systemic symptoms of fever, weight loss, diarrhea, edema, dyspnea, polydipsia, and polyuria, relate to specific organ involvement and single-system or multisystem disease presentation as noted below.
Specific organs are considered high-risk or low-risk organs when involved with disease presentation. Risk refers to the risk of mortality.
By Darci Picoult
It began with a bump. The size of a pinhead. Innocuous. An innocuous little pinhead of a bump on my vulva. Given that my gynecologist said the bump was probably nothing, I laughed it off. Which, in turn, made my bump mad. Very mad. It wanted my attention. And so it grew. I smeared it in medicine. It grew more. More medicine. More growth. Hanukkah came. Then Christmas. A war raged between us. I went to battle in the middle of the night with salt baths and creams. Prayed for its departure...
High-risk organs include liver, spleen, and bone marrow.
Low-risk organs include skin, bone, lymph nodes, gastrointestinal tract, pituitary gland, and central nervous system (CNS).
Additionally, patients may present with a single organ (single-system LCH), which may be a single site (unifocal) or involve multiple sites (multifocal); or LCH may involve multiple organs (multisystem LCH), which may involve a limited number of organs or it may be disseminated. Treatment decisions for patients are based upon whether high-risk or low-risk organs are involved and whether LCH presents as a single-system or multisystem disease. Patients can have LCH of the skin, bone, lymph nodes, and pituitary in any combination and still be considered at low-risk of death, although there may be relatively high-risk for long-term consequences of the disease.
Single-System Disease Presentation
In single-system LCH, as the name implies, the disease presents with involvement of a single site or organ, including skin and nails, oral cavity, bone, lymph nodes and thymus, pituitary gland, and thyroid.
Skin and nails
Infants: Seborrheic involvement of the scalp may be mistaken for prolonged cradle cap in infants. Infants may also present with brown to purplish papules over any part of their body (Hashimoto-Pritzker disease). Similar to that of stage 4S neuroblastoma, this manifestation may be self-limited as the lesions often disappear with no therapy during the first year of life. However, these patients must be watched very closely for systemic disease which may present after the initial skin lesions.[2,3] In a report of 61 neonatal cases from 1,069 patients in the Histiocyte Society database, nearly 60% had multisystem disease and 72% had risk organ involvement.
A review of patients presenting in the first 3 months of life with skin-only LCH, compared the clinical and histopathologic findings in 21 children whose skin LCH regressed with 10 children who did not regress. Patients with regressing disease had distal lesions that appeared in the first 3 months of life and were necrotic papules or hypopigmented macules. Nonregressing patients who required systemic therapy were more often intertriginous. Immunohistochemical studies showed no difference in IL-10, Ki-67, or E-cadherin expression and T-reg number between the two clinical groups.
Children and adults: Children and adults may develop a red papular rash in the groin, abdomen, back, or chest that resembles a diffuse candidal rash. Seborrheic involvement of the scalp may be mistaken for a severe case of dandruff in older individuals. Ulcerative lesions behind the ears, involving the scalp, under the breasts, or genitalia or perianal region are often misdiagnosed as bacterial or fungal infections.
Fingernail involvement is an unusual finding that may present as a single site or with other sites of LCH involvement. There are longitudinal, discolored grooves and loss of nail tissue. This condition usually responds to the common LCH therapies.