Undifferentiated Small Round Cell Sarcoma of the Hypopharynx in a 7-Month-Old Patient.

Undifferentiated small round cell sarcoma is an extremely rare and highly aggressive tumor touching the soft tissues and bones. Here, we report the case of a 7-month-old girl who presented to our department with respiratory distress due to a hypopharyngeal mass causing airway obstruction. The patient underwent a tracheotomy and had a direct laryngoscopy. Histological examination confirmed the diagnosis of an undifferentiated small round cell sarcoma. The patient received chemotherapy and radiotherapy and underwent neck dissection. One year later, the patient was diagnosed with local recurrence as well as metastatic cervical nodes and liver and pulmonary metastases. The case is original by the tumor's location and the age of onset. To the best of our knowledge, this could be the first case in English and French literature reporting an undifferentiated small round cell sarcoma affecting the hypopharynx among infants. The purpose of this article is to report our case and discuss its clinical and anatomopathological features as well as its prognosis and treatment options.