Sarcomatoid renal cell carcinoma: Rapid dissemination detected on FDG PET-CT GM Thambugala, 1 A Mohamed, 1,2 GFA O’ Neill 3 and MJ Fulham 1,2 1 Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital, 2 The Faculty of Medicine, University of Sydney, and 3 St Vincent’s Clinic, Sydney, New South Wales, Australia SUMMARY We present the FDG PET-CT findings in a patient with persistent pain 7 weeks after a nephrectomy and lymph node dissection for a sarcomatoid renal cell carcinoma. Although conventional imaging was unable to detect evid- ence of metastatic spread outside the para-aortic nodes, a PET-CT scan showed unexpected extensive dissemination. Currently, there are no reports in the literature of the PET-CT findings in sarcomatoid renal cell carcinomas. Key words: bladder neoplasm; fluorodeoxyglucose 18 F; PET-CT; sarcomatoid renal cell carcinoma. INTRODUCTION Farrow et al. first described sarcomatoid renal cell carcinomas (RCC) in 1968. They identified it as an RCC that contained malignant spindle cells and had histological features similar to a sarcoma. 1 They are uncommon primary renal tumours and in the largest reported study of 2381 patients with renal tumours, sarcomatoid RCC accounted for 5%. 2 Other investigators, in smaller series, have reported a range from 1.2 to 23.6%. 3 Patients usually present with pain and haematuria and less commonly with weight loss, fatigue, gastrointestinal symp- toms, fever and night sweats. 3 The mean age at presenta- tion is 60 years and men are slightly more commonly affected than women. 4,5 These tumours have a poor prognosis with a median survival after diagnosis that ranges from 6 to 19 months. 3,5,6 Common sites of spread include regional nodes, the contralateral kidney, bone, liver, lungs and brain. 3,4 A variety of chemotherapy and immunotherapy regimens have been trialled, but the results are dismal. 3 We present the PET-CT findings in a patient with extensive disseminated sarcomatoid RCC. CASE REPORT A 52-year-old man presented to his local doctor with a 2-month history of vague epigastric discomfort, which was worse after meals and left loin pain. There was a past history of a lumbar laminectomy, but otherwise he had been well. A series of inves- tigations were carried out by the local doctor. Serum creatinine was 0.156 mmol/L – the reason for this was uncertain as there was no past history of chronic renal failure, diabetes or hyper- tension. A non-contrast CT kidneys, ureter and bladder and triple phase CT scan of the abdomen and pelvis, showed a mass lesion in the left renal pole extending into the anterior perirenal fascia, which was associated with hydronephrosis. There were also enlarged left para-aortic lymph nodes. The patient was then referred to a urological surgeon. Abdominal ultrasound confirmed the CT findings. A bone scan was carried out and it was normal. A fine-needle aspiration biopsy of the renal mass and left para-aortic lymph nodes was carried out under CT guidance and pathology showed spindle cells that were positive for vimentin and Cam 5.2. The histopathological diagnosis was a sarcomatoid RCC. Because there was no evidence for metastatic disease outside the left regional lymph nodes, sur- gery was carried out through a transabdominal approach. A left radical nephrectomy, left adrenalectomy and a left para-aortic lymph node dissection were carried out. The nodal mass was adherent to the aorta and left renal vein. Pathology confirmed a sarcomatoid RCC and four of seven para-aortic lymph nodes were involved with tumour. GM Thambugala BSc (Med), MB BS; A Mohamed MB BS, FRACP; GFA O’ Neill MB BS, FRACS; MJ Fulham MB BS, FRACP. Correspondence: Professor Michael J Fulham, Department of PET and Nuclear Medicine, Building 63, Level A7, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia. Email: mfulham@med.usyd.edu.au Submitted 17 December 2005; accepted 06 February 2006. doi: 10.1111/j.1440-1673.2006.01664.x Case Report Australasian Radiology (2006) 50, 604–606 ª 2006 The Authors Journal compilationª 2006 Royal Australian and New Zealand College of Radiologists