Involvement of the omentum in Wegener's granulomatosis.

A 70 year old male patient was admitted to the outpatient clinic because of chronic fatigue, weight loss, generalised joint aching, arthritis of the ankles, and renal insufficiency. His medical history was unremarkable. At physical examination, increased central venous pressure, subfebrile temperature of 38.4 C̊, tender and swollen ankles, and painful flexion and extension were observed. Laboratory investigation showed an erythrocyte sedimentation rate of 70 mm/1st h, haemoglobin 5.1 mmol/l, leucocytes 18.66 10/l, eosinophils 670610/l, serum creatinine 369 mmol/l, urea 18.0 mmol/l, and urine sediment with 20–50 erythrocytes, 0–5 leucocytes, and several casts of the urinary tract epithelial lining. Positive tests for antineutrophil cytoplasmic antibodies with a cytoplasmic pattern (c-ANCA) and antigenic specificity for proteinase 3 were found. A renal biopsy disclosed focal necrotising intraand extracapillary glomerulonephritis, with crescents fitting a diagnosis of Wegener’s granulomatosis (fig 1). Because of rapid renal and pulmonary deterioration immune suppressive treatment and dialysis were started clinically. However, during the initial stage of this treatment, the patient suddenly experienced severe abdominal pain. Emergent radiological examination by computed tomographic scan showed diffuse intra-abdominal bleeding of unknown origin. Laparotomy revealed a massive intraabdominal loss of blood. Diffuse intraperitoneal bleeding was uncovered, especially in the greater omentum, which had to be excised. Gastrointestinal perforations were not seen. Histological examination of the resected omentum diagnosed focal necrotising vasculitis of the venules of the omentum (fig 2). After this the patient soon recovered, and treatment with corticosteroids and cyclophosphamide was continued for 18 months. From that time cyclophosphamide could be discontinued and the patient has been followed up to the present without exacerbations of Wegener’s granulomatosis. DISCUSSION To our knowledge this is the first case which describes severe, biopsy verified involvement of the omentum, complicated by massive intra-abdominal bleeding in a patient with Wegener’s granulomatosis. Severe gastrointestinal involvement in Wegener’s granulomatosis has been reported occasionally, although abdominal involvement may be detected in a significant number of patients at necropsy. The main complications include intestinal perforation, ulceration, ischaemia, and haemorrhage in both the small and large intestine. As in the case presented here, gastrointestinal disease occurred shortly after diagnosis and the start of immunosuppressive treatment in these previous reports. 2 A relationship between this therapeutic strategy in active disease and the occurrence of intestinal necrosis and perforation of the intestinal tract, or involvement of the omentum in our case, however, seems to be unlikely. The long term improvement of the disease without further severe intestinal disease seen in our patient, who was treated with cyclophosphamide for over 18 months after occurrence of severe intra-abdominal bleeding, does not support such a relationship. Another point to be made concerns the need for surgery. Our case clearly shows that intra-abdominal bleeding requiring immediate surgical intervention may complicate Wegener’s granulomatosis. Therefore diagnosing haemorrhage is important as other causes of acute abdominal pain—for example, splenic rupture or abscess, perforation of a hollow viscous or ruptured aortic aneurysm, may also need emergency laparotomy. As stated before, this may happen early in the course of the disease or even at onset of the disease, especially in patients with existing severe renal and pulmonary involvement. 5 Although rare, severe necrotising vasculitis of the omentum should be considered in the differential diagnosis of acute abdominal pain in patients with rapidly proceeding Wegener’s granulomatosis. Figure 2 Biopsy of the greater omentum: focal necrotising vasculitis of the venules.