Challenging treatment of parameningeal rhabdomyosarcoma with leptomeningeal metastasis: Case report and review of literature.

Parameningeal rhabdomyosarcomas (PM RMSs) are rarely seen childhood tumors. Their treatment might be challenging and prognosis is poor compared to other head and neck RMS. Here we report a PM RMS presenting with leptomeningeal seeding metastasis a year after diagnosis. A five-year-old girl presented with an enlarging mass protruding from the right ear and right facial paralysis. Magnetic resonance imaging (MRI) revealed a large mass extending from right external auditory canal to the temporal lobe, pterygoid fossa and nasopharynx with an intracranial component indenting the right temporal lobe and extending into the right cavernous sinus. Trucut biopsy revealed embryonal rhabdomyosarcoma. Cerebrospinal fluid (CSF) cytology was negative for malignant cells. Chemotherapy was started since it was found unresectable. At second week of chemotherapy, radiotherapy was applied to primary tumor location with intensity-modulated radiation therapy (IMRT) technique in 1.8 Gy fractions to total dose of 50.4 Gy. At week 27, MRI showed significant response. At week 36, the patient presented with vomiting and tendency to sleep. MRI was found to be compatible with meningitis and antibacterial therapy was started. At week 39, chemotherapy was stopped. But MRI performed one month later revealed linear contrast enhancements around the spinal cord compatible with leptomeningeal metastases. Chemotherapy and craniospinal irradiation were applied. But the patient did not improve and received palliative treatment. Six months after the completion of radiotherapy the patient died. Treatment of parameningeal rhabdomyosarcomas require multidisciplinary approach including surgery, radiotherapy, and chemotherapy. Prognosis is poor for patients with leptomeningeal spread.