SDPS-06 A 4 YEAR-OLD GIRL WITH EMBRYONAL RHABDOMYOSARCOMA IN RETROAURICULAR AND MIDDLE EAR : A RARE CASE REPORT FROM INDONESIA

Rhabdomyosarcoma is the most common sarcoma of childhood, and this tumor is the third most common neoplasm after neuroblastoma and nephroblastoma. Rhabdomyosarcomas may originate in any anatomical site, occurring predominantly in head and neck regions, orbits, skull base, nasal cavity, and nasopharynx, where there is little or no musculoskeletal tissue. The involvement of the ear and mastoid bone in rhabdomyosarcoma is uncommon. The embryonal rhabdomyosarcoma includes about 60– 70% of rhabdomyosarcoma cases. A four years-old girl presented with pain in neck and difficult to moving, there was a mass in the left auricular that was getting bigger. 4 days prior to admission, there was a drooping mouth to the left, the voice sounds hoarse, but there was no weakness in the side and no loss of consciousness. On physical examination, there was a N.VII palsy, without hyperreflexia, paraplegia, and nystagmus. High resolution Mastoid CT-Scan showed a characteristic malignant solid mass involving the external acoustic canal and the left tympanic and mastoid cavities, destroying the auditory and temporal bones, involving the left internal acoustic canal, and reaching the left nasopharynx, extending into the intracranial region of the left cerebellopontine angle and left temporal duramater. In Pathology examination showed Tumor cells are spherical, spindle-shaped with pleomorphic nuclei, hyperchromatic, coarse chromatin, vesicular, some with real nuclear daughters, eosinophilic cytoplasm. Mitosis is discovered. eccentricallynucleated cells with eosinophilic cytoplasm, suggesting rhabdomyoblast differentiation, some with a "tadpole" appearance, and conclusion according to embryonal rhabdomyosarcoma. The patient is treated with chemotherapy using Vincristine, Actinomycin-D, and Ifosfamide.