Uncommon Presentation of Granulomatosis with Polyangiitis Mimicking Metastatic Lung Cancer

Abstract

Diagnosis of anomalous intrathoracic lesions may be challenging and require a multidisciplinary approach. We present a case of granulomatosis with polyangiitis (GPA) clinically and radiologically mimicking metastatic lung cancer with a bilateral pulmonary mass, mediastinal and cervical lymph node involvement, and pleural effusion. Surgical biopsy of the thoracic lesion revealed necrotic granulomatous inflammation, and the final diagnosis was subsequently confirmed by kidney biopsy and biochemical parameters. This case illustrates how comprehensive diagnosis secures timely and relevant treatment. Systemic vasculitis may be one of the key differential diagnoses in patients with multiorgan involvement, especially with pattern-mimicking lung cancer.

Pulmonary involvement of ANCA-associated vasculitis in adult Chinese patients

“…Finally, this is the first study to document the bronchoalveolar lavage and pulmonary function results of patients with AAV-related pulmonary involvement in detail, confirming that these results differ based on the radiological images and that DLCO might partially predict patient outcomes. Given that patients with PG are relatively rare and partially similar to the radiological pattern of lung cancer [ 28 , 29 ], the clinical utility of transbronchial lung biopsy at the time of AAV diagnosis should be considered. In summary, we observe that patients with different types of lung involvement have unique clinical characteristics.…”

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

“…Granulomatosis with polyangiitis is a rare multisystem disease with an incidence of 20 per million population per year [2]. It is characterized by small vessel vasculitis, necrotizing granulomatous inflammation of Reumatologia 2022; 60/6 the upper and lower respiratory tract and kidneys, and the presence of ANCA antibodies [6,7].…”

“…In fact, most of the publications discuss misdiagnosis of vasculitides as cancer [2,16,17]. Reports of coexistence of systemic vasculitis and lung cancer are scarce and limited to case reports [18][19][20] and small case report series [21,22]: exposure to cyclophosphamide seems to be one of the main causes of development of lung cancer in patients with GPA, while a case report of a new onset GPA in a patient with known lung adenocarcinoma is unique [23].…”

“…Therefore, many practicing medical researchers recommend considering anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) as a differential diagnosis for patients with atypical manifestations of malignancies (including suspected solid tumors and hematologic malignancies). Data regarding lung cancers with coexisting systemic vasculitis with pulmonary manifestations are quite limited [2].…”