A Rare Evolution: Mediastinal Mature Teratoma Undergoing Somatic-Type Malignant Transformation to Rhabdomyosarcoma

Abstract

Mediastinal mature teratomas are typically benign tumours that predominantly occur in the anterior mediastinum. However, rare cases of malignant transformation within mature teratomas have been documented, most commonly involving somatic-type malignancies. This case report presents a 46-year-old female with productive cough and persistent right lung consolidation despite a course antibiotic and Mycobacterium tuberculosis workout negative. Histopathological examination (HPE) revealed a high-grade epithelioid tumour with myogenic and neuroendocrine differentiation, consistent with alveolar rhabdomyosarcoma with neuroendocrine features. The patient underwent chemotherapy. This case report discusses a unique presentation of a mediastinal mature teratoma with somatic-type malignant transformation into rhabdomyosarcoma in a middle-aged female and highlights the importance of considering rare malignancies, such as rhabdomyosarcoma, in the differential diagnosis of a persistent mediastinal mass, though rare, can significantly alter prognosis and treatment strategies