A Case of Pulmonary Sarcoidosis Following Diagnosis and Treatment of Follicular Lymphoma in an Individual With Crohn's Disease

Introduction: Sarcoidosis is a multisystem disease characterized by noncaseating granulomatous inflammation. The interaction of host immunologic, genetic, and environmental factors are thought to lead to the development of sarcoidosis as well as Crohn's disease. In this setting of a dysregulated immune response leading to granulomatous inflammation, an association between sarcoidosis and malignancy has been observed, particularly with lymphoproliferative malignancies. We present a case of pulmonary sarcoidosis diagnosed after follicular lymphoma. Case Report: A 68-year-old female with a history of Crohn's disease and follicular lymphoma treated with chemotherapy and rituximab presents with progressive dyspnea on exertion. A renal mass was incidentally identified on imaging, resulting in a diagnosis of low-grade follicular lymphoma on biopsy. She was treated with chemotherapy and rituximab. Two years after diagnosis and treatment of follicular lymphoma, she developed progressive dyspnea on exertion and shortness of breath. Laboratory results were notable for a low 25-hydroxyvitamin D level and elevated inflammatory markers. Computed tomography (CT) imaging of the chest revealed hilar and mediastinal lymphadenopathy, with upper and middle lung zone predominant peribronchovascular and centrilobular micronodularity (Figure). Pulmonary function testing demonstrated impaired diffusion capacity (61% predicted). Bronchoscopy with bronchoalveolar lavage revealed lymphocytic alveolitis, and transbronchial biopsies demonstrated parenchymal non-necrotizing granulomas, at which point the diagnosis of pulmonary sarcoidosis was made. Discussion: While several studies have demonstrated an association between sarcoidosis and malignancy, it is unclear whether sarcoidosis predisposes to malignancy, or whether the diagnosis and treatment of malignancy leads to development of sarcoidosis. Patients with sarcoidosis have a more than five-fold increased incidence of hematologic malignancy, referred to as the “sarcoidosis-lymphoma syndrome.” With this syndrome, patients develop lymphoma after sarcoidosis. The presence of noncaseating granulomas in the lymph nodes or non-regional tissue of patients with malignancy has been observed and described as a “sarcoid-like reaction;” this differs from sarcoidosis in that patients do not have accompanying systemic symptoms. There is evidence to suggest that malignancy may predispose to development of sarcoidosis. It is unclear whether the diagnosis of sarcoidosis after malignancy is due to a causative relationship, or the result of increased surveillance in patients that have completed treatment for a malignancy. Furthermore, the impact of Crohn's disease has been reported with sarcoidosis and lymphoma, raising a question of shared genetic and/or exposure risk with these entities. This case demonstrates the diagnostic and therapeutic challenges associated with the development of malignancy and sarcoidosis. (Figure Presented).