INTRODUCTION Paragangliomas are rare tumours arising from neuro- ectodermally derived paraganglionic tissue that is dispersed along the autonomic ganglia. They have a variable natural history; the majority (and in particular those associated with the parasympathetic fibres of the cranial nerves (e.g. chemodectoma)) tend to be indolent or locally invasive only. In contrast, paragangliomas of the retroperitoneum or media- stinum have the highest metastatic potential (20–40%). Metastatic sites commonly include lymph nodes, bone, lung and liver. Retroperitoneal paragangliomas can be divided into those arising from the adrenal medulla (phaeochromocytoma) and those (the remaining 10%) arising from the retroperitoneal sympathetic chain. CASE REPORT A 77-year-old woman was first seen in the Radiation Oncology Department of Westmead Hospital in December 1998. She had previously been referred to a neurosurgeon in March 1998 with a 4-month history of intermittent back pain radiating down the back of both legs. Imaging at this time revealed a sacral mass but a fine needle biopsy (FNA) was non- diagnostic. Open biopsy was subsequently performed (1 April 1998) and was also non-diagnostic. The patient was then regularly reviewed by her neurosurgeon. Her pain gradually increased in both intensity and frequency, and by October she required increasing analgesics and had to sleep sitting upright in a chair. She also noticed reduced sensation in the soles of both feet. An MRI (10 November 1998) demonstrated a mass lesion destroying the first two sacral segments and encircling the exiting upper sacral roots (Fig. 1). On T1 sequencing the mass demonstrated low-to-intermediate signal, with hyperintensity on short inversion time inversion recovery (STIR) images. Compared to the March CT scan, the lesion was larger. Repeat FNA was performed on 24 November 1998 and it was reported as showing malignant cells that were moderately pleomorphic and occurring in loosely cohesive fragments. Many of the tumour cells had abundant cytoplasm and appeared fragile with numerous stripped nuclei. Some scattered intact cells were also present and had granular cytoplasm and distinct cell borders. Lymphoma was excluded on the basis of morphology and negative leucocyte common antigen. The appearances were consistent with a large cell malignant tumour. At this stage the patient was referred to radiation oncology. The patient’s medical history included thyroidectomy for multinodular goitre and, significantly, she had undergone resection of a retroperitoneal paraganglioma in 1992. Current medications included thyroxine and analgesics. She had never smoked, rarely drank alcohol and lived with her well husband. There was no family history of cancer. On examination she was a frail, elderly woman with an Eastern Cooperative Oncology Group (ECOG) performance Case Report Malignant retroperitoneal paraganglioma: Case report and review of treatment options George Hruby, 1 Margot Lehman, 2 Michael Barton 3 and Tony Peduto 4 1 Department of Radiation Oncology, Royal Prince Alfred Hospital, Camperdown, Departments of 2 Radiation Oncology and 4 Radiology, Westmead Hospital, Westmead and 3 Department of Radiation Oncology, Liverpool Hospital, Liverpool, New South Wales, Australia SUMMARY A case of retroperitoneal paraganglioma metastasizing to bone is presented. This is followed by a literature review of treatment options, including external beam radiotherapy, chemotherapy and 131 I-metaiodobenzylguanidine. Key words: chemotherapy; malignant paraganglioma; metaiodobenzylguanidine; radiotherapy. Australasian Radiology (2000) 44, 478–482 G Hruby FRANZCR; M Lehman FRANZCR; M Barton FRANZCR; T Peduto FRANZCR. Correspondence: Dr G Hruby, Toronto-Sunnybrook Regional Cancer Centre, 2075 Bayview Avenue, Toronto, Ontario M4N 3M5, Canada. Email: george.hruby@tsrcc.on.ca Submitted 19 July 1999; resubmitted 31 October 1999; accepted 25 May 2000.