HISTIOCYTOSIS X = RETICULOENDOTHELIOSIS= (LCH) LANGERHANS CELL HISTIOCYTOSIS

TUMOR LIKE CONDITIONS OF THE TEMPORAL BONE

(LIKE ORBITAL PSEUDOTUMOR, POLYMORPHIC RETICULOSIS, AND ALL MIDLINE GRANULOMATOUS Dz ARE ALL LOCALIZED VARIANTS OF EXTRANODAL ANGIOCENTRIC PERIPHERAL T-CELL LYMPHOMAS)—-THIS INFO HAS COME INTO PLAY SINCE IMMUNOHISTOCHEMITRY—-ON BX LOOK LIKE A NECROTIC MASS WITH HISTIOCYTIC INFILTRATE

3 VARIANTS ALL INVOLVING THE SKIN, SKELETON, AND R. E. SYSTEM

PROLIFERATION OF LANGERHANS DENDRITIC CELLS(BILOBED NUCLEUS)

PRIMARILY PRESENT AS OTITIS MEDIA

BIRBECK BODIES ON E.M.(PENTILAMINAR CYTOPLASMIC INCLUSION BODIES

)-LOOK LIKE A ZIPPER (PAS +) ALPHA MANNOSIDASE AND PEANUT LECITHIN +

SEVERITY IS ALPHABETICAL AND AGE RELATED

LETTERER-SIWE

(“BETTER SEND A LETTER”)–ERICH LETTERER 1924

1^ST YEAR OF LIFE—MULTISYSTEM DZ

INFANTS, RARE, RAPIDLY FATAL, SCALP RASH, LAD, PULM Dz, H-S MEGALLY, O.C. MANIFESTATIONS, FEVER

HAND-SCHULLER-CHRISTIAN Dz

–ALFRED HAND–PEDIATRICIAN 1893

MALE>FEMALE

10% CLASSIC TRIAD = LYTIC “PUNCHED OUT” SKULL LESION, D.I., EXOPTHALMOS

30% MORTALITY

Rx: RT

EOSINOPHILIC GRANULOMA (EG) OF BONE

OLDER CHILDREN (5-15), PRIMARILY FRONTO-TEMPORAL

Rx: SURGICAL EXCISION

NEW NOMENCLATURE –UNIFOCAL LCH, MULTIFOCAL LCH CONFINED TO SKELETAL SYSTEM, MULTIFOCAL LCH WITH SOFT TISSUE INVOLVEMENT

MAY TREAT ALL LIKE LYMPHOMAS = RT, CYTOXAN, STEROIDS, CURETTAGE