CASE 79
By: Dr. Amna Kashgari MD,SSC-Rad
HISTORY: A 5-year-old with history of palpable swelling in his left side of his head.
What are the finding?
What is your differential diagnosis?
FINDINGS:
Frontal and lateral radiographs of the skull (A) demonstrate a well define lytic lesion with sharp edges located in the cortex of the left parietal bone.
Non-enhanced axial head computed tomography (CT) (B) shows right frontal skull lesion that involves the entire thickness of the skull with bevelled edges. Adjacent soft tissue component noted.
Enhanced axial head computed tomography (CT) (C) shows enhancing soft tissue component adjacent to the skull defect with no intracranial component.
DIFFFERENTIAL DIAGNOSIS:
LCH.
Ewing sarcoma.
Metastasis.
Osteomyelitis.
DIAGNOSIS:
Langerhans cell histiocytosis.
PEARLS AND DISSCUSSION:
Langerhans cell histiocytosis (LCH) is rare idiopathic disorders characterised by idiopathic proliferation and accumulation of Langerhans cells within various tissues. The nature if LCH as neoplastic or inflammatory process is still debatable.
The annual incidence in children estimated at 4.6 per million in children.
Types:
| Type | Age of presentation | Involvement |
|---|---|---|
| Uni-focal (localized) | 5-15y |
- Single bone or few bone -Lung |
| Multifocal uni-system (Chronic recurring) | 1-5y |
- Multiple bones - Reticuloendothelial system (the liver, spleen, lymph nodes, and skin)
|
| Multifocal multisystem (Fulminant) | First 2 years of life | - Multiple organs |
“Eosinophilic granuloma, Hand-Schüller-Christian disease, histiocytosis X, and Letterer-Siwe disease are older names for the three groups that used when LCH thought to be several different diseases; these names should now be disregarded”
Radiological findings:
Bone involvement in children presents as a single or multiple osteolytic lesion. Their border appear either well or poorly defined with or with out periostitis. They usually show a single layer of periosteal bone “buttressed pattern”. The edge of the lesion is quite characteristic described as beveled edge with non-sclerotic margin, especially if the skull is involved. When the axial skeleton is involved, it causes vertebral body collapse “Vertebra plana”, mostly involving thoracic spine.
In Nuclear scan, 35% of the lesions are negative in bone scan and not Ga-67 avid.
The lesion heals completely either by excision or chemotherapy with complete sclerosis.
FURTHER READING:
Lloret I, Server A, Taksdal I. Calvarial lesions: a radiological approach to diagnosis. Acta Radiol 2009; 50:531542.
Jatin Zaveri, MD Quan La, MD Gail Yarmis et al. More than Just Langerhans Cell Histiocytosis: A Radiologic Review of Histiocytic Disorders. RadioGraphics 2014; 34:2008–2024.
Lane F Donnelly. Fundamental of pediatric radiology. ISBN-13: 978-0721690612
