PO:34:207 | When the Lungs Speak in Squeaks: Chronic Bird-Related HP in SSc-ILD with Incidental Lymphoma

Mariagrazia Nuara¹, Marco De Pinto², Amelia Spinella², Stefania Cerri^1|2, Enrico Clini^1|2, Dilia Giuggioli^1|2 | ¹Università degli Studi di Modena e Reggio Emilia, Italy; ²AOU, Policlinico di Modena, Italy

Background. Systemic sclerosis (SSc) is an autoimmune systemic disease characterized by fibrosis of the skin and internal organs. Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease (ILD) triggered by repeated exposure to inhaled antigens in susceptible individuals. We describe a complex case of limited cutaneous SSc (lcSSc) complicated by ILD, chronic fibrosing HP, and incidental diagnosis of pulmonary extranodal marginal zone lymphoma. Case report: An 81-year-old woman with a 25-year history of lcSSC (CENP-B+), non smoker, presented with progressive dyspnea, ongoing since 2008. She had never received specific treatment for SSc. ILD was first documented in 2017, and for rapid progression oxygen therapy was initiated in 2019. She came to our attention in 2021. HRCT showed a pattern of diffuse fibrosing interstitial lung disease, more pronounced in the subpleural regions of the lingula, the middle lobe, and the lower lobes. It is characterized by smooth reticular thickening of the interstitium, areas of increased ground-glass parenchymal density, and associated bronchiolectasis, and mildly enlarged hilar and mediastinal lymph nodes. Pulmonary function tests revealed a mild restrictive defect (FVC 72%) and severely reduced DLCO (23%). To investigate the lymphadenopathy, an EBUS was performed, raising suspicion for a B-cell lymphoproliferative disorder. A subsequent PET/CT showed that the known consolidation in the left lower lobe had become more globular with homogeneous radiotracer uptake (SUV = 13). A lung biopsy confirmed the presence of an indolent B-cell lymphoma with features of extranodal marginal zone lymphoma. Given its indolent nature, no immediate oncologic treatment was indicated, and follow-up was planned. During a multidisciplinary (rheumatologic-pulmonologic) evaluation (2024), the patient reported worsening dyspnea and dry cough. Physical examination showed SpO2 of 92% on 2 L/min oxygen, bibasilar crackles, and diffuse bilateral late-inspiratory squeaks and wheezes. The patient has refused any specific pharmacological treatment for SSc. Upon detailed environmental history, the patient reported chronic exposure to goose feather pillows used continuously for over 40 years. HP was suspected and removal of antigen sources was recommended. Serology revealed markedly positive avian precipitins (>50 mg/L), supporting a diagnosis of chronic fibrosing HP. The patient later confirmed removal of the feather-filled pillow. Due to symptomatic worsening, treatment with mycophenolate mofetil (2 g/day) was started and a close clinical-radiological follow-up was maintained.

Conclusions. This case highlights the diagnostic and therapeutic complexity of managing ILD in the context of SSc, complicated by overlapping chronic HP related to avian antigen exposure and incidental low-grade lymphoma. It underscores the importance of multidisciplinary evaluation in such complex scenarios, allowing individualized management when multiple coexisting pathologies are present.