Pulmonary manifestations of Wegener’s granulomatosis (WG) range from asymptomatic nodules, fleeting infiltrates to alveolar haemorrhage.¹ A mediastinal mass was considered an unlikely feature of WG and its presence was regarded as an alternative diagnosis.² We report on a patient with WG who presented with a mediastinal mass and an elevation of the left hemidiaphragm, initially thought to be thymoma. Thymectomy disclosed extensive inflammation composed of necrotising vasculitis and extravascular granuloma. To our knowledge, this unusual presentation of WG mimicking thymoma has not been reported previously.

CASE REPORT

A 34 year old man was referred to our hospital with a thymic tumour. The patient had had vague chest pain for 1 year and, 3 weeks before admission, the pain became aggravated. There was no past history of allergic diseases such as bronchial asthma. At hospital chest radiography showed a wide mediastinum with an elevation of the left diaphragm (fig 1A⇓), and chest computed tomography (CT) disclosed a lobulated tumour in the anterior mediastinum with an ill defined margin extending from the aortic arch to the precordial region, and subcarinal lymphadenopathy.

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Figure 1

 (A) A chest x ray examination showed a wide mediastinum with an elevation of the left hemidiaphragm. (B) Pathological examination showed extensive acute inflammation composed of necrotising vasculitis affecting small sized vessels (inset, original magnification ×200), extravascular granulomas with multinucleated giant cell formation (arrowhead), and prominent inflammatory infiltration (haematoxylin and eosin, original magnification ×100).

On examination, vital signs were stable and others were unremarkable. Laboratory tests showed leucocytes 13.8×10⁹/l with 10.7% eosinophils, platelets 505×10⁹/l, and erythrocyte sedimentation rate 50 mm/1st h. The patient received thymectomy, and pathological examination showed extensive inflammation composed of necrotising vasculitis affecting small to medium sized vessels, and extravascular granuloma with multinucleated giant cell formation (fig 1B⇑). The antineutrophil cytoplasmic antibody was positive (×160 cytoplasmic type) and other autoantibody tests were negative.

Sudden onset of dyspnoea with haemoptysis occurred and CT disclosed bilateral diffuse consolidation compatible with alveolar haemorrhage. Methylprednisolone pulse therapy 1 g for 3 days was prescribed and followed by daily prednisolone 1 mg/kg. Nasal mucosa ulcerations and palpable purpura were noted. A skin biopsy showed leucocytoclastic vasculitis.

After taking account of the clinical manifestations, pathological findings, and serological tests, the diagnosis of WG was concluded. Cyclophosphamide treatment was started with daily Endoxan 2 mg/kg. However, proptosis of the eyes and bilateral hand ischaemic changes appeared. Renal function deteriorated, with microscopic haematuria (70–80 red blood cells/high power field, proteinuria (1.2 g/24 h), and raised blood creatinine levels (210 μmol/l). An etanercept injection 25 mg twice a week was added. Disease activity subsided gradually and the elevation of the hemidiaphragm was reversed. Daily prednisolone and Endoxan doses were tapered to 0.5 mg/kg and 1 mg/kg, respectively and etanercept was discontinued after 2 months.

Neutropenia was noted and Endoxan was withheld. Swallowing difficulty with pain developed. Endoscopy showed oesophagitis with ulcerations, and an oesophagogram showed a narrow lumen with poor motility. Respiratory failure was noted and the patient received bronchoscopy and a CT examination, which disclosed lower tracheal and endobronchial stenosis with diffuse wall thickening and lumen narrowing. His disease was complicated with several episodes of infection, including pneumonia, cellulitis, and urinary tract infection. High dose steroid treatment (prednisolone 1 mg/kg/day) was continued, but Endoxan was not prescribed. He died from sepsis 7 months later after admission to hospital.

DISCUSSION

A fulminant disease with a full pattern of organ involvement was found in our patient. Churg-Strauss syndrome does not produce destructive airway disease such as endobronchial stenosis or alveolar haemorrhage, and occurs exclusively in patients with asthma.³ Blood and tissue eosinophils have been found in WG.⁴

Respiratory involvement is a common manifestation of WG; however, mediastinal manifestations, both as presenting events or during the course of disease, are rare.¹ In a comprehensive review of 302 patients with WG, only three cases had mediastinal masses.² Unilateral phrenic nerve paralysis with hemidiaphragmatic elevation was recognised in only one patient with WG without any mediastinal mass.⁵ The hemidiaphragmatic elevation in that case occurred at the late stage independently of disease flare.

Our patient received conventional treatment and etanercept treatment. Tumour necrosis factor α has a central role in inflammation and granuloma formation, and current experimental approaches to the treatment of WG include strategies designed to disrupt tumour necrosis factor α.⁶ A preliminary study of etanercept treatment showed an encouraging effect in WG and randomised trials were under way.⁷

A mediastinal mass with left hemidiaphragmatic elevation mimicking thymoma has not been reported previously in patients with WG. It is important to recognise the presenting features of WG, because early treatment is essential for a favourable outcome.