Paraganglioma of the anterior superior mediastinum: Presentation of a case of mistaken diagnosis so long and review of the literature.

INTRODUCTION AND IMPORTANCE: Mediastinal paraganglioma is a rare tumor with neuroendocrine activity, highly susceptible to misdiagnosis. Herein, we present a case misdiagnosed as Castleman disease for nearly a decade, significantly enlarged, lost the opportunity of thoracoscopic surgery, and was removed by median thoracotomy.

CASE PRESENTATION: A 59-year-old woman complained of having a mediastinal mass, was diagnosed with Castleman disease for nearly a decade and was admitted to the hospital due to neck tightness. The tumor size was significantly enlarged. We proceeded to interventional angiography with gelatin sponge angioembolization, and the tumor was resected through a median sternotomy on the second day. The operation was smooth, and the tumor was gray and slightly brittle. Postoperative pathology confirmed paraganglioma; lymph node metastasis was not detected (0/3).

CLINICAL DISCUSSION: Mediastinal paraganglioma is a rare tumor and can be either functional or nonfunctional. It can be differentiated from many diseases. The SSTR-PET-CT labeled with 68Ga-somatostatin analog, plasma metanephrine, and normetanephrine are essential for the diagnosis. Surgical resection is the most effective form of treatment. Pre-operative embolization of the feeding artery is considered to have a low rate of intraoperative bleeding. We recommend making comprehensive preparations to ensure perioperative safety and long-term survival.

CONCLUSION: When a vascularized mass is discovered in the mediastinum, surgeons should consider the possibility of a paraganglioma. Multidisciplinary consultation should be involved in the formulation of treatment plans. Lifelong surveillance for residual tumor growth and recurrence is required.