Langerhans cell histiocytosis
D. Perform biopsy of lesion
Performing a biopsy (choice D) allows for proper diagnosis and management. A diagnostic biopsy through a lateral orbitotomy revealed histiocytic cells with abundant eosinophilic cytoplasm and enlarged nuclei with lobation of the nuclear membrane (Figure 2). The CD207 immunohistochemical stain was diffusely positive, consistent with Langerhans cell histiocytosis (LCH).
The differential diagnosis of a sphenoid wing mass in a child includes rhabdomyosarcoma, Ewing sarcoma, LCH, metastasis, and infection. Although the external examination results were suggestive of orbital cellulitis, the patient was afebrile and there was no obvious source of infection; thus, intravenous (IV) antibiotic therapy (choice B) would be inappropriate. An inflammatory lesion was possible; however, the extent of the process and involvement of the temporal lobe would make the use of IV corticosteroid therapy (choice C) inappropriate. Although a metastatic lesion was possible, a positron emission tomographic scan (choice A) prior to biopsy would not be desirable. Performing a biopsy (choice D) would be essential to determine the diagnosis.