Langerhan’s cell histiocytoses

• Classified into different syndromes by clinicoanatomical patterns

• Letterer-Siwe syndrome

  • AKA acute disseminated Langerhan's cell histiocytosis

  • Malignant, with systemic infiltrates

  • Seen in kids < 3 YOA and may be present at birth (something similar happens in adults)

  • F is followed by a diffuse maculopapular eczematous or pruritic rash with subsequent enlargement of the spleen, liver, and nodes throughout the body

  • Cystic lesions may appear in the skull, pelvis, and long bones

  • Cytopenias are frequent and are from marrow involvement

  • Death usually from intercurrent infections and progressive anemia

• Unifocal Langerhans cell histiocytosis

  • AKA eosinophilic granulomas

  • Solitary, expanding, erosive accumulation of histiocytes with a variable admixture of eosinophils, lymphocytes, plasma cells, and neutrophils

  • Necrosis and multinucleated histiocytes may be present

  • Usually in medullary cavity of bones (skull, ribs, and femur most often)

  • Benign lesion in kids and adults, usually males; lesions can be asymptomatic or painful, and pathological fractures can occur

  • Sometimes spontaneous fibrosis and healing occur within a few years

• Multifocal Langerhans cell histiocytosis

  • More disabling, onset before 5 YOA

  • Patients have F, a diffuse, scaly skin eruption (especially on scalp and in the ear canals), and frequent bouts of otitis media, mastoiditis, URI, and gingival inflammation; mild lymphadenopathy, hepatomegaly, and splenomegaly due to histiocytic infiltrates may be present

  • About 50% have DI

  • Orbital granulomas may produce exophthalmos (calvarial bone defects, DI, and exophthalmos = Hand-Schuller-Christian triad)

  • Good prognosis…50% have spontaneous remission and chemo is curative in the remainder

Category: Medical Subject Notes , Pathology Notes