16 month old girl with head lump and fever

Radiographs – Several areas of bony destruction in the left mandible and both the frontal and left parietal bones. Review of the lesion in the frontal bone shows lytic destruction of both the inner and outer tables (affecting the outer table more). This gives a beveled margin.

Eosinophilic granuloma, Epidermoid/ dermoid, neuroblastoma metastases, leukemia, osteomyelitis, haemangioma

Eosinophilic granuloma or Langerhans cell histiocytosis (LCH)

Calvarial involvement of LCH more often involves the parietal or frontal bone before the skull base. Although typically appearing as well defined lesions, they unevenly involve the inner and outer tables, and can also show ill-defined or frayed margins. This results in a beveled margin such as in the image above. These lesions infrequently cross the suture, unlike neuroblastoma metastases, which tend to deposit along and widen the sutures.

Sometimes, an isolated bone island can be seen within the lesion, and referred to as a “button sequestrum”. This supports a diagnoses of LCH, although osteomyelitis can look similar. Mandibular lesions also tend to involve the alveolar bone, giving a “floating teeth” appearance.

• Hindman BW, Thomas RD, Young LW, Yu L. Langerhans cell histiocytosis: unusual skeletal manifestations observed in thirty-four cases. Skeletal Radiol. 1998 Apr; 27(4):177-81.
• Stull, M. A., M. J. Kransdorf, and K. O. Devaney. “Langerhans cell histiocytosis of bone.” Radiographics 12.4 (1992): 801-823.