The clinical presentation, radiograph, and histology slide are diagnostic of eosinophilic granuloma. Eosinophillic granuloma is a tumor like condition secondary to proliferation of histiocytes and most commonly occurs in the skull, skin, or skeleton. It can occur in just about any bone but is common in the spine or the flat bones of the pelvis or shoulder girdle, long bones, and skull. Radiographically, eosinophilic granuloma occurs as lytic lesions without significant surrounding sclerosis as seen in Figure A. Histology shows the characteristic multiple eosinophils with their characteristic oval "coffee bean" nuclei and staining pattern of purple/red/pink cytoplasm (depending on the stain). Importantly, the histology slide lacks a malignant appearance (no cellular atypia or mytotic complexes and low nuclear:cytoplasmic ratio). Skin lesions like those shown in Figure A are common.
Neuroblastoma, Ewing's sarcoma, and acute lymphoblastic leukemia are all common pediatric neoplasms which have classic presentations such as the young age and abdominal mass common for neuroblastoma, the characteristic translocation in Ewing's sarcoma, and the diagnostic histology and toxic clinical presentation in acute lymphoblastic leukemia. Fifth's disease is an infectious disease caused by the parvovirus B19.
Simon MA, Springfield D, eds. Surgery for Bone and Soft-Tissue Tumors. Philadelphia, PA: Lippincott-Raven; 1998:198-200.
Springfield DS, Bolander ME, Friedlaender GE, Lane N. Molecular and cellular biology of inflammation and neoplasia. In: Simon SR, ed. Orthopaedic Basic Science. Rosemont, IL: American Academy of Orthopaedic Surgeons; 1994:219-276.