A40-53 When Nodules Collide: Pulmonary Hyalinizing Granuloma in Sjögren’s Syndrome

Abstract Pulmonary hyalinizing granuloma (PHG) is a rare lung disease that usually presents as nodules or masses and can be mistaken for malignancy or infection on imaging. Its etiology remains unclear, but it is frequently associated with autoimmune diseases, chronic inflammation, or prior infection. Given its nonspecific radiographic features PHG presents a diagnostic challenge, especially in patients with connective tissue disorders. A 64-year-old woman with long-standing Sjögren’s syndrome and interstitial lung disease, presented with a 20-year history of progressive dyspnea, morning joint stiffness, xerostomia, and xerophthalmia. Serologic testing revealed elevated ANA (1:320, speckled), positive anti-SS-A/Ro antibodies, rheumatoid factor (90 IU/mL), and anti-NXP-2 antibody, with normal IgG4 levels. Pulmonary function testing confirmed severe restrictive impairment and markedly reduced diffusion capacity. CT dating back at least 4 years demonstrated a usual interstitial pneumonia (UIP) pattern with a straight edge sign, the four corners sign and anterior predominance, consistent with connective tissue disease-associated ILD (CTD-ILD). Four years prior, lung biopsy showed pattern consistent with Nonspecific Interstitial Pneumonia. In the year leading up to her death, she was found to have Pseudomonas pneumonia within the cystic lung at the left base. We suspect chronic infection-related inflammation caused bilateral disease progression, with imaging now revealing thick consolidative opacities in both the lung apices and bases. PET-CT showed diffuse hypermetabolic activity in consolidative areas. Due to severe functional impairment, she received a bilateral lung transplant but died from surgery-related complications. Gross examination of explanted lungs revealed multiple firm, coalescent nodules within areas of fibrosis. Histopathologic analysis showed dense, lamellar, keloid-like hyaline collagen arranged concentrically around vessels with perivascular lymphoplasmacytic infiltrates, these findings were consistent with PHG. Special stains were negative for amyloid, iron, and infectious organisms. This case demonstrates the potential consequences of uncontrolled inflammation in patients with ILD and emphasizes the importance of considering empirical treatment due to the elevated risk of significant complications in advanced lung disease. In patients with Sjögren’s syndrome and progressive ILD, the coexistence of fibrotic and nodular lesions can obscure the distinction between progressive fibrosis, neoplasia, and rare entities such as PHG. Although corticosteroids and immunosuppressive agents may stabilize disease in select cases, no standardized therapy exists. Lung transplantation remains the only curative option in end-stage disease. Pulmonary hyalinizing granuloma should be considered in patients with autoimmune disorders and atypical pleural thickening or nodular consolidations. This abstract is funded by: None