A Case of Gaucher Disease With Atypical Presentation Mimicking Chronic Recurrent Multifocal Osteomyelitis.

We present the case of a nine-year-old male who presented with recurrent bony pain episodes since the age of four, requiring multiple hospital admissions. Initial workup showed anemia, thrombocytopenia, prolonged prothrombin time (PT), partial thromboplastin time (PTT), and elevated C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The patient underwent an open biopsy of the right femur with irrigation and debridement that was inconclusive, but cultures were positive for methicillin-resistant Staphylococcus aureus (MRSA) and group G hemolytic streptococci that were treated with clindamycin. Differential diagnosis was broad with a negative workup for malignancy, chronic granulomatous disease, infectious causes, sarcoidosis, and vasculitis. Multiple MRIs were consistent with bilateral femur osteomyelitis, right proximal tibia, and right humerus osteomyelitis with negative cultures on subsequent admissions. The patient was diagnosed with chronic recurrent multifocal osteomyelitis (CRMO). He had clinical and laboratory improvement for two years on methotrexate. He was then tried on a short course of steroids and adalimumab for worsening symptoms. Bone biopsy was repeated, and findings were consistent with Gaucher disease (GD), which was confirmed on biochemical testing with low beta-glucosidase activity. He was started on enzyme replacement therapy with clinical and biochemical improvement.