Sarcoidosis: It's in the Bones

Abstract

SESSION TITLE: Fellow Case Report Poster - Diffuse Lung Disease II SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 25, 2016 at 01:30 PM - 02:30 PM INTRODUCTION: Sarcoidosis, a multisystem disease characterized by non-caseating granulomas, typically affects the lungs. Osseous sarcoidosis should be considered when bone lesions are detected. CASE PRESENTATION: A 57 year old man who presented as a trauma was found to have diffuse FDG avid lytic bone lesions throughout his spine, ribs and pelvis. There was no primary malignancy on imaging and bone biopsy showed only histiocytes. Urine free light chains were detected and although all multiple myeloma criteria were not met by bone marrow biopsy, chemotherapy was initiated. Two months later, the lytic bone lesions were unchanged but there were new FDG avid pulmonary infiltrates, mediastinal and abdominal lymphadenopathy. Chemotherapy stopped. The patient had back pain but denied respiratory symptoms. Prior imaging showed bilateral hilar adenopathy. Transbronchial biopsy of the pulmonary density showed non-caseating granulomas. AFB and fungal stains were negative. Repeat iliac bone biopsy showed giant multinucleated cells consistent with granulomatous process. Pulmonary and osseous sarcoidosis was diagnosed and treated with prednisone which transitioned to methotrexate. At 3 months the back pain resolved as had the FDG avidity of the bone lesions, lymphadenopathy and pulmonary infiltrates. DISCUSSION: Sarcoidosis involves bones in up to 10% of cases. Hands and feet are most commonly involved, however long bones and axial skeleton can be affected. Osseous involvement is a late finding often seen with pulmonary sarcoidosis. Half of patients are asymptomatic. Vertebral body involvement is more likely to cause radicular back pain. As osseous sarcoidosis can appear radiographically as lytic, sclerotic or punched out lesions and is FDG avid, it can can mimic malignancy. Bone biopsy is required to exclude malignancy or fungal / mycobacterial infections. Pathology will show non-caseating granulomas, macrophages, epitheliod and giant multinucleated cells. Immunosupression with prednisone, methotrexate or biologics have all been successful. Duration of treatment remains unclear. CONCLUSIONS: We highlight a case of osseous sarcoidosis with concurrent pulmonary sarcoidosis. Once a diagnosis of pulmonary sarcoidosis was established, bone biopsies were consistent with osseous sarcoidosis. Sarcoidosis is often managed by pulmonologists so familiarity with extrapulmonary manifestations is important. Reference #1: Sparks et al. Osseous Sarcoidosis-Clinical characteristics, Treatment and Outcome Seminars in Arthritis and Rheumatism 44 (2014) 371-379 DISCLOSURE: The following authors have nothing to disclose: Ewa Rakowski, Angeliki Kazeros No Product/Research Disclosure Information