Growing Teratoma Syndrome Revealed By F-18 FDG PET/CT

Introduction

Germ cell neoplasia in situ (GCNIS)-associated tumors encompass both seminomatous and non-seminomatous germ cell tumors (NSGCT), with teratoma being a subtype of NSGCT [1]. Growing teratoma syndrome (GTS) is a rare benign tumor that manifests as metastases of the teratoma component in patients with germ cell tumors, despite the normalization of tumor markers during and after chemotherapy. It has three main components: clinical enlargement of tumors during or after chemotherapy, normalization of previously elevated tumor markers, and presence of only mature elements upon histologic examination of the tumor [2]. The diagnosis is established by sequential radiological imaging and the presence of mature teratoma remnants in the surgical specimen. These growing teratomas are resistant to chemotherapy and radiation therapy, therefore extensive surgeries may be needed [3]. Patients with disease on imaging, even if stable, should continue to be followed as these lesions can begin to grow even years later [4]. We present a rare case of testicular-derived GTS identified by F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and confirmed by histopathology.

Publication History

Received: 15 January 2024

Accepted after revision: 20 February 2024

Article published online:
14 March 2024

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