Mature cystic teratomas of the mediastinum are typically germ cell tumors with indolent growth, with documented annual growth rates often less than 5 centimeters. We report a case with an abnormal growth rate (Average diameter growth rate 7.14 mm/month) and significant increased 18 F fluorodeoxyglucose (18 F FDG) uptake, which challenges conventional diagnostic concepts. A 34-year-old female presented with progressive chest tightness. Serial CT imaging revealed a right anterior superior mediastinal mass that grew from approximately 1.5 cm in long diameter to 6.5 cm over 7 months (Average diameter growth rate 7.14 mm/month). 18 F fluorodeoxyglucose Positron Emission Tomography-Computed Tomography(18 F-FDG PET/CT) revealed the lesion with high metabolic heterogeneity, and the maximum standardized uptake value (SUVmax 6.9). Pathological examination after thoracoscopic-assisted complete resection confirmed the diagnosis of mature cystic teratoma with mature glial components. This case suggests that lesions with rapid growth and significantly increased FDG uptake do not necessarily indicate malignant transformation of teratoma. Multidisciplinary decision-making should be based on dynamic quantitative imaging and metabolic feature analysis.Categories: Pathology, Oncology, Pulmonology.
Shi et al. (Sun,) studied this question.