Ewing's Sarcoma Masquerading as Osteomyelitis

Fulminant soft-tissue extension of anaplastic multiple myeloma masquerading as postoperative abscess

“…10 This likely contributed in this patient, as aggressive anaplastic intramedullary myeloma cells infiltrated and proliferated in the extramedullary postoperative hematoma, leading to swelling, drainage, and fulminant disease. Most notably, Ewing sarcoma can masquerade as osteomyelitis, 11 especially with a vague clinical picture and nonspecific elevated laboratory parameters, as were present in our patient. 9 Distinguishing infectious from neoplastic etiologies is sometimes difficult, even when the diagnosis seems apparent.…”

Tumours and Tumour-Like Lesions of Bone

“…MRI can be used to accurately quantify the extent of the soft tissue mass both prior to and after chemotherapy (Ozaki et al 1995). The main differential diagnosis for ES in the small bones of the hands is osteomyelitis, and misdiagnosis can lead to significant delay in treatment (Durbin et al 1988).…”

Cutaneous metastases from Ewing's sarcoma: report of two cases

“…Immunohistochemically, neoplastic cells of neuroblastoma express immunoreactivity for neurone‐specific enolase, neurofilament protein, protein general product 9.5, chromogranin, and synaptophysin. For differential diagnosis between Ewing's sarcoma and neuroblastoma, the presence of p30/32, the product of the MIC 2 gene (designated CD99), has recently been identified as a relatively specific cell marker of Ewing's sarcoma, but not for neuroblastoma 9,10 …”

“…Ewing's sarcoma is considered to be a poorly differentiated neoplasm, whereas MPNET often shows definite signs of neuroectodermal differentiation 12 . The CD99 monoclonal antibody directed against the cell surface glycoprotein p30/32 MIC 2 is expressed by both neoplasms, and it is considered to be highly sensitive although not entirely specific 9,10 . A diagnosis of MPNET may be established on the basis of light microscopic features, consisting of sheets or lobules of small rounded cells containing darkly staining, round or oval nuclei.…”

“…For differential diagnosis between Ewing's sarcoma and neuroblastoma, the presence of p30 ⁄ 32, the product of the MIC2 gene (designated CD99), has recently been identified as a relatively specific cell marker of Ewing's sarcoma, but not for neuroblastoma. 9,10 MPNET and Ewing's sarcoma are two histogenetically related neoplasms. Most cases of these neoplams share the cytogenetic translocation t(11; 22) (q24;q12), 11 and the tumours are considered to be neoplasms with neuroectodermal differentiation, although to different degrees.…”