Ewing's sarcoma is a rare malignant tumor of the foot in children. We report a case of Ewing's sarcoma of the talus in a four-year-old Chinese girl to highlight the initial difficulty in diagnosis and the clinical course of the disease. She was initially diagnosed as osteomyelitis of the talus and died eight months after presentation with pleural and spinal metastases. To the best of our knowledge, Ewing's sarcoma of the talus in a young child has never been reported in Malaysia.
A 19-year-old girl presented to the rheumatology clinic for left knee monoarthritis for the past 4 months. She also had constitutional symptoms with significant weight loss. On physical examination, she appeared cachexic, her left knee was swollen and tender. MRI of the left knee showed a soft tissue swelling extending into the knee joint. Left knee synovial fluid showed small round cells. Histopathology results were compatible with Ewing's sarcoma. Due to the delay in seeking medical advice, she succumbed to the disease 1 week after the diagnosis was made. Soft tissue/bone tumour causes monoarthritis is not common. A careful history taking, physical examination and investigations should be done in order to identify a sinister cause of monoarthritis such as Ewing's sarcoma. Early treatment should be initiated to ensure a better outcome.
Ewing sarcoma (ES)/ primitive neuroectodermal tumour (PNET) is an aggressive malignant neoplasm affecting mainly children and young adults. The tumour is included with other primitive neoplasms under the category of small round cell tumour. Cytokeratin expression in ES/PNET has been described in sporadic case reports as well as a few systemic series. We studied this feature in Malaysian patients diagnosed in University Malaya Medical Centre on the basis of typical morphology and immunohistochemical assays. Immunohistochemical staining for AE1/AE3 and MNF116 were performed in 43 cases. Cytokeratin was expressed in 17 cases (39.5%) in focal, intermediate or diffuse patterns. There was no significant association between cytokeratin immunoreactivity and the following parameters: patient age, sex, skeletal and extraskeletal primary location as well as primary, metastastic or recurrent tumours or chemotherapy treatment. A significant association between cytokeratin and neuron specific enolase (NSE) expression was demonstrated. Our study supports evidence of epithelial differentiation in ES/PNET and emphasizes that the expression of cytokeratin does not exclude ES/PNET in the differential diagnosis of small round cell tumours.
Primary primitive neuroectodermal tumour (PNET) and extraskeletal Ewing's sarcoma belongs to the Ewing's family of tumours. Primary tumours arising from breast are very rare. There are only a few case reports published on primary extraskeletal Ewing's sarcoma and PNET arising from breast. We present an extremely rare case of an inoperable primary Ewing's sarcoma arising from left breast with contralateral breast, lymphatic and lung metastasis.