uria. The following investigations were negative or normal: antinuclear antibody, antiglomerular basement membrane antibody, serum electrophoresis, hepatitis B and C, and human immunodeficiency virus serology. His prostate-spe- cific antigen was 20.5 mg/L; CA19-9 was not raised. He had a positive c-antineutrophil cytoplasmic antibody (ANCA) with positive proteinase 3 antibody at 24 Au/mL (range 0–10). A skin biopsy was not done. The following tests revealed no evidence of malignan- cy: bronchoscopy and biopsy, pleural fluid and urine cytology, upper and lower gastrointestinal endoscopy, cystoscopy, and prostate biopsy. Computerized tomo- graphy (CT) of the thorax and abdomen showed a focal, low soft-tissue-density mass within the liver consistent with metastasis; bowel gas obscured the pancreas, and the pros- tate was enlarged (Figure 1). He was started on prednisolone and methotrexate (stopped once results of the CT scan were available), and his purpura disappeared, and inflammatory markers returned to normal. A liver biopsy was planned, but the patient died suddenly after a respiratory arrest. Postmortem examina- tion revealed pulmonary embolism secondary to a deep vein thrombosis. A moderately differentiated adenocarcinoma of the pancreas was found, with liver and peritoneal met- astases. Paraneoplastic vasculitis associated with solid tumors is rare. In a review, 1 only 36 of more than 200 patients who had simultaneous cancer and vasculitis had a solid tumor, the majority had hematological malignancy. Bronchogenic carcinoma is the cancer most frequently associated with vasculitis. 2,3 ANCA is usually negative in secondary vasculitis. There are few reports of ANCA-associated paraneoplastic vasculitis. 4 Only two previous reported cases of pancreatic carcinoma and vasculitis could be found, and both were associated with Wegener’s granulomatosis. 5,6 Diagnosis of vasculitis in this patient was based on the clinical picture, with involvement of skin and possibly kidney (hematuria) and lung (hemoptysis). The history of epistaxis and retinal vein occlusions raises the possibility of Wegener’s gran- ulomatosis with positive c-ANCA. The role of the patient’s medications, including antibi- otics, in the vasculitis is unlikely, because drug-induced vasculitis is usually ANCA negative. This patient had pancreatic carcinoma, which is also associated with Trousseau’s syndrome. The development of recurrent superficial thrombophlebitis characterizes this syndrome. Thrombi may occur in the arterial or the venous system. Patients typically have thromboembolic phenome- na that are manageable with heparin-based anticoagula- tion, 7–9 but these conditions are unresponsive to warfarin. 7 This syndrome is most commonly associated with solid tumors of the adenocarcinoma type. Pancreatic tumors, es- pecially those of the body or tail, seem to be associated with the highest risk of this syndrome. 10 This patient had thrombophlebitis and a pulmonary embolism some months before admission, for which he was on warfarin. He also had a history of retinal vein oc- clusions. He was taking low-molecular-weight heparin dur- ing his admission, which should have been more effective than warfarin and a suitable alternative to unfractionated heparin. 8,9 No case report has been found of paraneoplastic vasculitis caused by pancreatic carcinoma and Trousseau’s syndrome in the same patient. In summary, a patient with a solid neoplasm, c-ANCA positive paraneoplastic vasculitis, and Trousseau’s syn- drome is presented. Because malignancy is associated with ANCA-positive vasculitis, it should be considered as part of the differential diagnosis in patients presenting with vasculitis. Diagnosis is important, because immunosup- pressive regimens have the theoretical risk of provoking malignancy or its dissemination. Radcliffe Lisk, MRCP Paul G. O’Mahony, MRCP Elderly Care Department Mayday University Hospital Croydon, Surrey, England ACKNOWLEDGMENTS Financial Disclosure: None. Author Contributions: Both authors were equally in- volved in the writing of this letter. Sponsor’s Role: None. REFERENCES 1. Kurzock R, Cohen PR, Markowitz A. Clinical manifestations of vasculitis in patients with solid tumours: A case report and review of the literature. Arch Intern Med 1994;154:334–340. 2. Hayem G, Gomez MJ, Grossin M et al. Systemic vasculitis and epithelioma. A report of three cases with a literature review. Rev Rheum Engl Ed 1997;64:816–824. 3. Greer J, Longley S. Edwards et al. Vasculitis associated with malignancy. Ex- perience with 13 patients and literature review. Medicine (Baltimore) 1988; 67:220–230. 4. Pankhurst T, Savage CO, Gordon C et al. Malignancy is increased in ANCA- associated vasculitis. Rheumatology 2004;43:1532–1535. 5. Christl SU, Borchard F, Keller R et al. [Pancreatic tail tumor as an unusual first manifestation of Wegener’s disease.]. Z Gastroenterol 2004;42:513–516. German. 6. Christi SU, Borchard F, Keller R et al. Wegener’s granulomatosis masquerading as pancreatic carcinoma. Dig Dis Sci 1992;37:702–704. 7. Callander N, Papaport SI. Trousseau’s syndrome. West J Med 1993;158: 364–371. 8. Zuger M, Demarmels Biasiutti F, Wuillemin WA et al. Subcutaneous low- weight-heparin for treatment of Trousseau’s syndrome. Ann Hematol 1997; 75:165–167. 9. Morita S, Gebska MA, Kakkar AK et al. High affinity binding of heparin by necrotic tumour cells neutralises anticoagulant activity-implications for cancer related thromboembolism and heparin therapy. Thromb Haemost 2001; 86: 616–622. 10. Pinzon R, Drewinko B, Trujillo JM et al. G. Pancreatic carcinoma and Trousseau’s syndrome: Experience at a large cancer center. J Clin Oncol 1986;4:509–514. ESTIMATING GLOMERULAR FILTRATION RATE MIGHT HELP TO AVOID HYPOGLYCEMIA To the Editor: In elderly diabetic patients, concealed renal failure (depressed glomerular filtration rate (GFR) despite normal serum creatinine levels) can increase the risk of ad- verse drug reactions to hydrosoluble drugs. 1 Among hypo- glycemic drugs, metformin is highly hydrosoluble, whereas the liver metabolizes sulfonylureas to hydrosoluble met- LETTERS TO THE EDITOR 1469 JAGS SEPTEMBER 2006–VOL. 54, NO. 9