Herlina Eka Shinta

EMBRYONAL RHABDOMYOSARCOMA IN CHILDREN: A CASE REPORT Herlina Eka Shinta*, Ni Putu Sriwidyani* INTRODUCTION Embryonal rhabdomyosarcoma (ERMS) is one of the most malignant diseases of childhood soft tissue sarcoma, more common in children aged 1 to 5 years old and adolescents Most tumors located at the neck and head (50%), fewer than 9% arise in the skeletal musculature of the extremities. CASE REPORT An 1-years-old boy presented with a mass in the left femur, the size of the mass 4.0x5.0 cm, painless. The MRI examination showed defined mass with necrotic component, minimal bleeding, pressing the muscle and surrounding tissue.. Histopathologically showed cellular tumor composed of small cells with elongated round to ovoid nuclei, eosinophilic cytoplasm, hyperchromatic of nuclear chromatin, mitosis can be found. The malignant cells form hemangioperisitic pattern. The conclusion was atypical small round cell tumor with differential diagnosis was embryonal rhabdomyosarcoma. Desmin immunohistochemistry stain showed positive in some cells, myoD1 positive in almost all nucleous, SMA negative, CD99 nonspecific, LCA and CD20 negative. The conclusion was support the diagnosis of embryonal rhabdomyosarcoma.

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Fig .1. Define mass in the left femur, the size of the mass 4.0x5.0 cm.Fig.2,3. defined mass with necrotic component, minimal bleeding, pressing the muscle and surrounding tissue. Fig.4. undifferentiated small round blue cells with welldifferentiated cartilage components. showed cellular tumor composed of small cells with elongated round to ovoid nuclei, eosinophilic cytoplasm, hyperchromatic of nuclear chromatin, mitosis can be found. The malignant cells form hemangioperisitic pattern. Fig. 5. Immunohistochemistry MyoD1 positive in almost all nucleous. Fig. 6. Desmin immunohistochemistry stain showed positive in some cells. Conclusion To reported ERMS femur on a boy age 1 year . Diagnosis is made by clinical , imaging , histopathology , and confirmed with immunohistochemistry examination. Refferences 1. Weiss W. Sharon, Goldblum R.John, Enzinger and Weiss’s Soft Tissue Tumor, fifth edition, Vol.1, 2008, P.599-608 2. Ognjanovic S, Linabery AM, Charbonneau B, et al.: Trends in childhood rhabdomyosarcoma incidence and survival in the United States, 1975-2005. Cancer 115 (18): 4218-26, 2009 3. Wood WC. Soft Tissue Tumors. In: Butcher I.editor. Oxford Textbook of Surgery 2nd ed. Oxford: Oxford University Press:2002.

Keyword : embryonal rhabdomyosarcoma, children, immunohistochemistry *Department of Pathology Anatomy, Faculty of Medicine Udayana University