Wegener's granulomatosis

(Friedrich Wegener, born 1907, German pathologist), an uncommon multisystem disease, characterized by necrotizing granulomas of the upper and lower respiratory tract together with glomerulonephritis and systemic vasculitis. This disorder can occur at any age and affects men and women equally.

Symptoms referable to the upper air passages are almost always present at some time in the course of the disease: nasal obstruction, purulent discharge, sinusitis, chronic ulceration and, in some cases, necrosis of nasal cartilage and bone. Cough, haemoptysis and pleurisy are usually accompanied by constitutional symptoms of malaise, weakness and fever.

Lesions occur in any part of the respiratory tract and take the form of inflammatory necrosis in the walls of small arteries and veins leading to occlusion of the lumen. Granulation tissue containing lymphocytes, polymorphs and giant cells represents a reparative process, but this also undergoes necrosis. The necrotic granulation tissue forms rubbery pulmonary masses which may be single or multiple.

Renal involvement with glomerulonephritis, which occurs in more than three quarters of patients, does not usually cause symptoms.

Pain in the muscles and joints or, occasionally, joint swelling affects two thirds of patients but does not lead to permanent joint damage or deformities.

Conjunctivitis, scleritis, episcleritis or an orbital mass lesion may be seen in some cases causing redness, burning or pain in the eye.

Nearly half of the patients with Wegener's granulomatosis develop skin lesions. These small red or purple raised areas or blister-like lesions, ulcers or nodules may or may not be painful.

Subglottic stenosis of the trachea can cause voice change, hoarseness, shortness of breath or cough.

Anaemia, elevated white blood cell count and platelet count, and an elevated sedimentation rate are commonly found. With renal involvement, red blood cells and casts are visible in the urine, and the creatinine and BUN may be elevated.

Rheumatoid and antinuclear factors are commonly found in the blood.

The most definite way to diagnose Wegener's granulomatosis is by performing a biopsy of an involved organ site (usually the sinuses, lung or kidney) to confirm the presence of vasculitis and granulomas, which together are diagnostic features of the disease.

Imaging

ChestGranulomatous masses up to several cm in diameter may be apparent on the chest radiograph. These are fairly well defined and often cavitate; they may resolve spontaneously, while new masses appear. Cavitating lesions may have thick or thin walls, depending on how much of the necrotic material is expectorated. Multiple cavities can closely mimic tuberculosis.

A diffuse pattern of disease, where the area of involved lung is still aerated but contains vaguely reticular or irregular nodular opacities, is also recognized. Relapse may occur in previously affected areas.

Other frequent radiographic signs are small pleural effusions and paranasal sinus opacification. Occasional complications are pneumothorax and subglottic stenosis, and granulomas may also develop in the trachea or bronchi and cause pulmonary collapse. Reactive hilar or mediastinal lymphadenopathy may be seen.

Sinuses

The majority of patients present with nonspecific changes in the sinuses such as mucosal thickening and opacity of the antra and other sinuses indistinguishable from a chronic rhinosinusitis. Progressive thinning and disappearance of part of the nasal septum is a distinctive change and is better shown by CT, which can also show the irregular, ulcerated surface of the lining granulomatous tissue. As with other inflammatory conditions, the latter gives a high signal on T2-weighted MRI sequences.

Kidneys

The urogram is frequently normal. In acute stages of glomerulonephritis, the kidney may be enlarged with a smooth outline, eventually becoming small in the later stages with generalized cortical atrophy. Any changes are usually bilateral and symmetric. Ultrasound appearances are nonspecific. An abnormally reflective renal cortex implies active interstitial disease.

Untreated, the disease has a poor prognosis with an average survival of 5 months, but therapy consisting of a combination of a glucocorticoid drug (prednisone) that reduces inflammation and a cytotoxic drug (cyclophosphamide ) that interferes with the abnormal growth of cells is used with good results.

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