C. Growing teratoma syndrome
Despite an excellent retroperitoneal and mediastinal tumor response to 4 cycles of VIP chemotherapy, this patient’s left supraclavicular mass continued to enlarge. While chemorefractory metastasis was in the differential diagnosis, normalization of tumor markers and radiographic appearance on magnetic resonance imaging indicated the diagnosis of growing teratoma syndrome (GTS). Surgical resection was performed given the high risk of mechanical compression of surrounding neck vasculature owing to unchecked teratoma growth. Final pathology results demonstrated mature teratoma tissue, confirming the diagnosis of GTS.
Growing teratoma syndrome was first described in 1982 by Logothetis et al,1 in which 6 patients with metastatic germ cell tumors were described to have enlarging abdominal and pulmonary masses despite successful chemotherapy regimens. The criteria by Logothetis et al1 for diagnosing GTS included (1) a normalization of β-human chorionic gonadotropin and α-fetoprotein values, (2) presence of a mass on examination that exhibited continual growth despite chemotherapy treatments, and (3) absence of any NSGCT malignant histologic characteristics on pathological examination.