CONCLUSION

Histiocytic disorders have a wide spectrum of radiologic appearances. Although many imaging appearances are nonspecific, familiarity with and knowledge of these disorders will facilitate their inclusion in the differential diagnosis. Imaging findings that are more specific include

lytic skull lesions with beveled edges, vertebra plana and patchy medullary osteosclerosis. Radiology plays a large role in the diagnosis and follow-up of patients with histiocytic diseases. Familiarity with the typical imaging appearances of histiocytic disorders is crucial for

appropriate patient management. Sixty percent of our patients had a solitary bone abnormality, and 40% of the patients had multiple lesions. Thus this data is comparable to that reported in the literature.

Bony manifestations of the Langerhans Cell Histiocytosis: A pictorial ReviewHafsa Shahwaiz Babar*, Anis ur Rehman*, Imran Khalid Niazi* *Shaukat Khanum Memorial Cancer Hospital and Research Centre, Radiology, Lahore, Pakistan

LEARNING OBJECTIVES

To discuss and illustrate the bony

manifestations of Langerhans cell

histiocytosis, as observed in different

imaging modalities.

To educate about wide spectrum of

radiologic appearances of histiocytic

disorders.

The study will also compare the frequency

of the various manifestations found in our

patients with those reported in the medical

literature.

BACKGROUND

Langerhans cell histiocytosis (LCH) describes

a group of syndromes that share the common

pathologic feature of infiltration of involved

tissues by Langerhans cells. Bony

manifestations of Langerhans cell

histiocytosis (LCH) are underestimated in

frequency and diversity.

Patients with apparently restricted LCH

require careful staging to rule out a more

extensive process. The clinical course is

generally benign, and sponta- neous

remissions are common. Single bone lesions

tend to resolve spontaneously over months on

years. Biopsy, performed for diagnosis, may

initiate healing with or without curettage.

When there is only lymph node involvement,

the prognosis is favorable and most patients

recover without therapy.

IMAGING FINDINGS

Bone lesions are found in most

patients with LCH, and painful

swelling is the most common initial

sign. The skull is most often

affected, followed in frequency by

the long bones of the upper

extremities and then the flat bones

(rib, pelvis, and vertebrae). There

may be adjacent soft-tissue

swelling. Older children and young

adults are more often affected.

0

10

20

30

40

50

60

skull pelvis femur ribs humerus mandible spine

TABLE 1. SITE DISTRIBUTION

Site %age

SKULL 50

PELVIS 23

FEMUR 17

RIBS 8

HUMERUS 7

MANDIBLE 7

SPINE 3

Fig 1: Huge lytic lesion with extra-osseous soft tissue component in the right iliac bone with uptake on PET Scan.

Fig 3 Lytic lesion

in the left pedicle

with uptake on

PET scan.

Fig 2. AP and lateral views of the right

femur shows a displaced fracture with an

underlying lesion.

Fig 4. Multiple lucenciies

involving the distal right

femoral diaphysis.

Fig 5. Axial and Coronal views of CT scan showing a

lytic lesion with irregular margins in the mandible on

right.

Fig 1. Axial images through MRI show a soft

tissue mass occupying left mastoid with

peripheral enhancement on contrast-enhanced

sequences.