The growing teratoma syndrome: results of therapy and long-term follow-up of 33 patients.

Growing teratoma syndrome (GTS) is defined as an increase in tumour size during or after chemotherapy for germ cell tumour (GCT), and only mature teratoma at histological analysis of the resected tumour specimen. Between 1985 and 1997, 30 male patients fulfilling GTS criteria were included in the present study. 3 female patients were also included but analysed separately. A mature teratoma component was found in 86% of the primary GCT. 3 male patients (10%) had a complication at diagnosis of GTS. One male patient (4%) having undergone complete resection (n=24) had a recurrent GTS, compared with all but 1 patient (83%) in whom resection was partial (n=6) (P<0.001). 2 (8%) and 3 (50%) male patients treated with complete and partial resection subsequently developed a malignant NSGCT respectively (P=0.01). 2 female patients treated with partial resection presented a recurrent GTS. One of them died of this recurrent GTS. GTS is an entity in its own right with respect to complications and the natural history of the disease. Complete surgical resection is the treatment of choice for GTS.