PARADOXICAL RESPONSE OF A PINEAL IMMATURE TERATOMA TO COMBINATION CHEMOTHERAPY

A case of primary intracranial germ cell tumour is reported in a 5-yea r-old Chinese boy who presented with symptoms and signs of increased i ntracranial pressure. Computed tomography (CT) scan of the brain revea led a multicystic tumour over the pineal region. Stereotactic biopsy y ielded enteric epithelium and isolated cells with hyperchromatic nucle i and high nuclear-to-cytoplasmic ratio, suggesting the diagnosis of a n immature teratoma. Grossly elevated serum and cerebrospinal fluid (C SF) levels of alpha-fetoprotein and mildly elevated levels of beta hum an chorionic gonadotrophin suggested the simultaneous presence of embr yonal tissues. Combination chemotherapy with cisplatin, etoposide, and bleomycin resulted in a gradual but complete normalisation of the ser um and CSF tumour markers. Paradoxically, the patient's consciousness deteriorated and repeat CT scan after 3 months of treatment showed tha t the tumour was actually increasing in size. Complete surgical remova l was attempted and histologic sections of the specimen revealed only mature teratomatous tissues. The child is now well and remains disease -free with minimal left hemiparesis 12 months after completion of trea tment. This case illustrates the importance of combined neoadjuvant ch emotherapy and surgery in the management of intracranial non-germinoma tous germ cell tumour harbouring both germ cell and teratomatous compo nents, while monitoring of both biochemical and radiological parameter s are necessary in assessing the clinical behaviour of mixed germ cell tumours. (C) Wiley-Liss, Inc.