Online ISSN : 1348-9992
Print ISSN : 0386-9628
ISSN-L : 0386-9628
Case Reports
A Case of Small Cell Lung Cancer with Complete Remission and PR3-ANCA Improvement by Chemotherapy
Hideto OshitaTatsuki TakahashiMisato SenooKunihiko FunaishiYasuyuki MitamaKen Okusaki
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2021 Volume 61 Issue 1 Pages 54-58


Background. Antineutrophil cytoplasmic antibodies (ANCA) are highly specific for ANCA-related vasculitis and are used to assist in its diagnosis. Although ANCA may also be present in patients with malignant tumors, few studies have reported lung cancer patients with false-positive ANCA tests. Case. A 66-year-old man was admitted to our hospital with suspected refractory pneumonia and was diagnosed with small cell lung cancer by bronchoscopy. Although his serum was positive for PR3-ANCA, no findings of vasculitis were observed, suggesting the false-positive detection of PR3-ANCA. Chemotherapy was effective against his lung cancer, and a complete remission was obtained, at which point his PR3-ANCA levels became negative. There was no recurrence of lung cancer and his PR3-ANCA level remained negative. Conclusion. Although rare, lung cancer patients may show false-positive ANCA tests results and their disease status may be evaluated according to the change in their ANCA titer.

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© 2021 by The Japan Lung Cancer Society
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