2020 Volume 27 Issue 1 Pages 17-23
Metachronous germ cell tumor (GCT) is defined as multiple histologically different tumors occurring at different sites with a long interval between occurrences. In the central nervous system, metachronous GCTs are extremely rare. The authors report a rare case of yolk sac tumor with repeated metachronous recurrences. A 37-year-old male presented with general malaise at our hospital. Seven years ago, he underwent partial resection of a pineal yolk sac tumor followed by gamma knife surgery (GKS) at another hospital. Imaging study showed a new lesion in the left basal ganglia and recurrence of the pineal lesion. Because serum alpha-fetoprotein (AFP) was elevated, we diagnosed these lesions as recurrence of the yolk sac tumor and performed GKS followed by chemotherapy (ICE and BEP). However, six years later, new lesions appeared in the neurohypophysis and right basal ganglia. Serum AFP was not elevated, but serum beta-human chorionic gonadotropin was slightly elevated. The pathological diagnosis of the biopsy specimen of the neurohypophyseal lesion was pure germinoma. We performed chemotherapy (CARE), followed by whole ventricular irradiation and local irradiation.
Two years later, a new large lesion appeared in the right parietal lobe and serum AFP was markedly elevated. We performed total resection of the tumor followed by local irradiation. The pathological diagnosis was mixed germ cell tumor (yolk sac tumor and embryonal carcinoma). Six months later, the tumor showed direct invasion into the scalp and multiple metastases to the lungs and spinal cord. Based on this case and previously reported cases, it is assumed that metachronous GCT tends to occur outside the previous radiation field; therefore, radiation therapy involving extended fields, such as craniospinal irradiation, could be effective in preventing metachronous GCT.
