ABSTRACT
Leukemia cutis (LC) is a rare neoplastic infiltration of the skin or subcutaneous tissue by leukemic cells. Because it correlates with sites of additional extramedullary involvement, it typically portends a poor prognosis. Although most cases of LC present concurrently with bone marrow infiltration, skin findings may precede systemic involvement in some cases; thus, early detection by dermatologists is essential. We report a case of a 66-year-old man who was diagnosed with acute myeloid leukemia (AML) based on the cutaneous presentation of LC.
Subject(s)
Leukemia, Myeloid, Acute/diagnosis , Skin Diseases/diagnosis , Aged , Arm , Diagnosis, Differential , Face , Fatal Outcome , Humans , Leukemia, Myeloid, Acute/complications , Male , Skin Diseases/complications , ThoraxABSTRACT
Langerhans cell histiocytosis (LCH) is an inflammatory neoplasia of myeloid precursor cells driven by mutations in the mitogen-activated protein kinase pathway. When disease involves the skin, LCH most commonly presents as a seborrheic dermatitis or eczematous eruption on the scalp and trunk. Evaluation for involvement of other organ systems is essential, because 9 of 10 patients presenting with cutaneous disease also have multisystem involvement. Clinical manifestations range from isolated disease with spontaneous resolution to life-threatening multisystem disease. Prognosis depends on involvement of risk organs (liver, spleen, and bone marrow) at diagnosis, particularly on presence of organ dysfunction, and response to initial therapy. Systemic treatment incorporating steroids and cytostatic drugs for at least one year has improved prognosis of multisystem LCH and represents the current standard of care.
Subject(s)
Histiocytosis, Langerhans-Cell/pathology , Histiocytosis, Langerhans-Cell/therapy , Multimorbidity , Adolescent , Biopsy, Needle , Child , Child, Preschool , Disease Progression , Female , Histiocytosis, Langerhans-Cell/classification , Histiocytosis, Langerhans-Cell/epidemiology , Humans , Immunohistochemistry , Incidence , Male , Prognosis , Rare Diseases , Risk Assessment , Severity of Illness IndexABSTRACT
A definitive diagnosis of Langerhans cell histiocytosis (LCH) requires a combination of clinical presentation, histology, and immunohistochemistry. The inflammatory infiltrate contains various proportions of LCH cells, the disease hallmark, which are round and have characteristic "coffee-bean" cleaved nuclei and eosinophilic cytoplasm. Positive immunohistochemistry staining for CD1a and CD207 (langerin) are required for a definitive diagnosis. Isolated cutaneous disease should only be treated when symptomatic, because spontaneous resolution is common. Topical steroids are first-line treatment for localized disease of skin and bone. For multifocal single-system or multisystem disease, systemic treatment with steroids and vinblastine for 12â¯months is the standard first-line regimen. Current research is seeking more effective regimens because recurrence rates, which increase the risk of sequelae, are still high (30-50%) in patients with multisystem disease. An active area of research is the use of targeted therapy directed at the mitogen-activated protein kinase pathway. Adequate follow-up to monitor for disease progression, relapse, and sequelae is recommended in all patients.
