Clinical utility of fine needle aspiration biopsy in the diagnosis of Wegener's granulomatosis. A report of two cases.

In two patients, pulmonary lesions of Wegener's granulomatosis (WG) were sampled by fine needle aspiration biopsy: one with the clinical diagnosis of primary pulmonary malignancy and the other with a clinical suspicion of WG. In the latter case the smears showed distinctive eosinophilic, collagen necrosis (pathergic necrosis), poorly formed granulomata composed of loose aggregates of elongated, often palisading epithelioid histiocytes, and multinucleate histiocytes. A cell block preparation in this case contained minute tissue fragments illustrating the distinctive, pathergic-type necrosis. In the former case, many of these features were present, but additionally there were several groups, atypical bronchial epithelial cells that, in light of the clinical impression, initially led to an incorrect diagnosis of bronchoalveolar carcinoma. Subsequent review of this case led to the diagnosis of WG. Antineutrophil cytoplasmic antibody (ANCA) serology was later obtained, confirming the diagnosis of WG in both cases. In our experience, the cytomorphologic findings of granular collagen necrosis, granulomata and multinucleate cells, although not specific, should alert the cytopathologist to consider the diagnosis of WG, especially when special stains for microorganisms are negative. A recommendation for ANCA serology testing early in the disease process, particularly in the limited forms of the disease, may lead to early recognition of WG, resulting in prompt institution of immunosuppressive therapy, greatly improving the patient's prognosis.