Langerhans cell histiocytosis (LCH) most commonly presents with a skin rash or a 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 when involved with disease presentation. Risk refers to the risk of mortality.
Cancer of the hypopharynx is uncommon; approximately 2,500 new cases are diagnosed in the United States each year. The peak incidence of this cancer occurs in males and females aged 50 to 60 years. Excessive alcohol and tobacco use are the primary risk factors for hypopharyngeal cancer.[3,4] In the United States, hypopharyngeal cancers are more common in men than in women. In Europe and Asia, high incidences of pharyngeal cancers, namely, oropharyngeal and hypopharyngeal,...
High-risk organs include liver, spleen, and bone marrow.
Low-risk organs include skin, bone, lung, lymph nodes, gastrointestinal tract, pituitary gland, and central nervous system (CNS).
Patients may present with a single organ (single-system LCH), which may involve a single site (unifocal) or multiple sites (multifocal). Bone is the most common single organ site. Less commonly, 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 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 with LCH may also present with a generalized skin rash, which may mimic many other skin disorders. Skin LCH in infants may be limited to skin (skin-only disease) or may be part of multisystem LCH. 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.
Skin-only LCH, which had historically been known as Hashimoto-Pritzer, may be self-limited as the lesions may disappear with no therapy during the first year of life. Therapy is used only for very extensive rashes, pain, ulceration, or bleeding. Importantly, these patients must be watched closely as skin-only LCH may also progress within weeks or months to high-risk multisystem disease, which may be life-threatening.[2,3,4]
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 ten 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. Patients with nonregressing disease who required systemic therapy were more often intertriginous. Immunohistochemical studies showed no difference in interleukin (IL)-10, Ki-67, E-cadherin expression, or 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. Vesicular lesions may be seen and need to be differentiated from herpetic lesions.
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 often responds to the usual LCH therapies.