A Rare Case of Rapidly Progressive Extragonadal Mature Cystic Teratoma Presenting With Chest Pain

Mature cystic teratomas represent the most prevalent subtype of germ cell tumors affecting the ovaries. Typically, these neoplasms are benign and characterized by a slow growth pattern. Nevertheless, malignant transformation of these tumors is a rare event that may occur. Despite their typically indolent behavior, some cases may exhibit rapid growth rates and give rise to a variety of complications, including rupture and consequent manifestation of a wide range of clinical signs and symptoms. This report details the case of a 49-year-old woman who presented to the hospital with a chief complaint of chest pain. The onset of her symptoms occurred several days prior to admission and was associated with fatigue without shortness of breath. Imaging studies, including computed tomography angiography and magnetic resonance imaging of the chest, revealed a mediastinal mass measuring 5.9 x 7.4 cm in a cross-sectional area that displayed features consistent with a mature cystic teratoma, including the presence of soft tissue, fat, fluid, and areas of calcification. Notably, a prior computed tomography scan of the chest, performed 20 months before her presentation, did not reveal any evidence of masses. The patient subsequently underwent successful robot-assisted resection of the mediastinal mass, with complete resolution of her symptoms. Histopathologic examination of the excised mass confirmed the absence of malignancy.