Histiocytosis X

Histiocytosis X

©  William Herring, MD, FACR

Histiocytosis XClassification

Letterer-Siwe disease

Hand-Schuller-Christian disease

Eosinophilic Granuloma

Letterer-SiweDisease

Letterer-SiweDisease

Letterer-Siwe DiseaseGeneral

10% of histiocytosis X

Acute disseminated, fulminant form

Age at onset

Several weeks to 2 years

Pathology

May be confused with leukemia

Letterer-Siwe DiseaseClinical

Hemorrhage, purpura

Severe anemia

Fever

Hepatosplenomegaly

Lymphadenopathy

Bone involvement in 50%

Widespread lytic lesions

Letterer-Siwe DiseasePrognosis

70% mortality rate

Hand-Schuller-ChristianDisease

Hand-Schuller-ChristianDisease

Hand-Schuller-ChristianGeneral

15-40% of Histiocytosis X

Age at onset

5-10 years

Pathology

May simulate Ewing'ssarcoma

Hand-Schuller-ChristianClinical

Triad of:

Exopthalmus (33%)

Diabetes insipidus (30-50%)

Lytic skull lesions

Hand-Schuller-ChristianTarget Organs

Bone

Soft tissues

Lung

Hand-Schuller-ChristianBone

Lytic skull lesions with overlying softtissue nodules

Large geographic skull lesions

“Floating teeth” with mandibularinvolvement

Hand-Schuller-ChristianSoft tissue

Hepatosplenomegaly is rare

Common in Letterer-Siwe

Lymphadenopathy may be massive

Hand-Schuller-ChristianLung

Cyst and bleb formation

Spontaneous PTX

EosinophilicGranuloma

EosinophilicGranuloma

Eosinophilic Granuloma

60-80% of Histiocytosis X

Usually confined to bone

Age at onset

5-10 years highestfrequency

Male predominance 3:2

Eosinophilic GranulomaGeneral

Location

Calvarium>mandible>spine>ribs>longbones

Most are monostotic (50-75%)

Eosinophilic GranulomaTarget Organs

Skull50%

Axial skeleton25%

Appendicular skeleton 15%

Lung20%

Eosinophilic GranulomaSkull

Most often diploic space of parietal bone

Round or ovoid punched out lesions withbevelled edge

Bevelled edge=hole-within-a-hole

Sclerotic margin during healing phase

Button sequestrum- bony sequestrumwithin lytic lesion

Beveled Edge Lytic Lesion ofEosinophilic Granuloma

Eosinophilic GranulomaAxial Skeleton

“Vertebra plana”-“coin-on-edge”(Calvedisease)=collapse of vertebral body

Mostly thoracic

Most common cause of vertebra plana inchildren

Vertebra plana in EosinophilicGranuloma

Eosinophilic GranulomaAppendicular Skeleton

Expansile, lytic lesion

Mostly diaphyseal

Soft tissue mass

Laminated periosteal reaction

Eosinophilic GranulomaLung

Age peak between 20-40 years

Multiple small nodules

Predilection for apices

Prototype for honeycomb lung

Recurrent pneumothoraces (25%)

Diffuse Reticular Interstitial Disease inEosinophilic Granuloma

Innumerable thin-walled cysts inEosinophilic Granuloma

Eosinophilic Granuloma with right-sided tension pneumothorax

Eosinophilic GranulomaNuclear Medicine

Negative bone scans in 35%

Bone lesions usually not Ga-67 avid

Ga-67 may be helpful in detectingnon-osseous lesions

Eosinophilic GranulomaPrognosis

Excellent

The End