Lessons of the month: ANCA-associated vasculitis - granulomatosis with polyangiitis: 'the great mimic'

What to Know About Biopsy Sampling and Pathology in Vasculitis?

PURPOSE OF REVIEW

To summarize the histologic findings of vasculitis, and to give some practical considerations on biopsy samples.

RECENT FINDINGS

The larger use of imaging and the discoveries of serological markers in the diagnosis of vasculitis have increased the clinical recognition of these entities. Nevertheless, biopsy remains the gold standard for diagnosis in most cases. So far, biopsies are also useful to obtain information about prognosis and to guide a more specific treatment. In recent years, less invasive diagnostic approaches have become available, lowering the risks related to the procedure and permitting a definite diagnosis in most cases. Histological examination permits a definite diagnosis of vasculitis. However, the findings may be nonspecific if not evaluated in the proper clinical setting. The interaction between clinicians and pathologists is crucial to obtain a definite diagnosis.

Pulmonary pattern in systemic vasculitis: granulomatosis, lung cancer or both?

As clinical manifestations of systemic vasculitides share many common features with other conditions, the rate of diagnostic errors and delayed diagnoses is high. Hence we performed an analysis of the available data regarding misdiagnosis of vasculitis as lung cancer and vice versa, as well as coexistence of vasculitis and lung cancer. The present case-based review highlights the diagnostic challenges encountered when granulomatosis with polyangiitis (GPA) mimics lung cancer. The importance of a multidisciplinary team approach to patients with pulmonary involvement and multisystem manifestations is essential for appropriate planning of further diagnostic steps and for minimizing the delay in correct diagnosis and treatment. In the present case, although computed tomography raised suspicion for lung cancer, further biopsies and laboratory screening for systemic vasculitides rejected malignancy and confirmed the diagnosis of GPA.