Introduction: Hibernoma is an uncommon benign tumor composed of multivacuolated brown adipocytes described in the literature a decade back. Intraosseous hibernomas are extremely rare with propensity to affect axial skeleton. Involvement of appendicular skeleton has been reported only twice in the literature till date. Case Report: We present a case of solitary, painless mass in the left proximal tibia mimicking neoplasm in a 35-year-old male. The plain radiographs revealed a lytic lesion with well-defined margin at the junction of metaphyseal-diaphyseal region of the left proximal tibia. The lesion was hyperintense on T2 and hypointense on T1 with heterogenous enhancement on contrast imaging. FDG-PET showed high uptake of fluorodeoxyglucose. Histopathological examination revealed the presence of multivacuolated cytoplasm with abundant mitochondria suggestive of hibernoma. On immunohistochemistry, the cells were positive for S-100. Conclusion: The findings of imaging modalities are non-specific and histopathological examination is required to confirm the diagnosis of hibernoma. Intraosseous hibernoma needs to be considered as a differential diagnosis of sclerotic bone lesion. Further, evaluation with regular follow-up with imaging will be required if the mass undergoes any clinical changes. Both radiologists and pathologists, need to be aware of this rare entity to avoid misdiagnosis of the uncommon lesion.

Introduction: Gaucher’s disease is a congenital lysosomal storage disorder caused by an autosomal recessive mutation in B-glucocerebrosidase. It is a multi-system disease, wherein patients present with hematological abnormalities, joint pain, osteonecrosis, and developmental delay. We present a case of 38-year-old male with a painless solitary soft-tissue swelling over the left proximal tibia, eventually diagnosed it to be a case of Gaucher’s disease. This case is unique in the literature, because this subcutaneous Gaucher mass was not associated with a significant past history and was being evaluated as a standard approach to a bone tumor. Case Presentation: A 38-year-old man presented to our outpatient department with a solitary, painless soft-tissue swelling of the left proximal tibia noticed 6 months back, which has gradually progressed to a present size of 9x5 cm over a period of 6 months. General physical examination revealed moderate splenomegaly. Radiographs showed an osteolytic lesion in the left proximal tibia without cortical erosion. Radiographs for skeletal survey revealed similar osteolytic lesions elsewhere. Hematological investigations revealed thrombocytopenia. A serum protein electrophoresis was found to be normal and the urine was negative for myeloma proteins. Blood workup for endocrine abnormalities was within normal limits. MRI of the lesion suggests bone infarct. Biopsy from the lesion showed a giant binucleate storage cell filled with glucocerebrosides suggestive of Gaucher’s disease. The diagnosis was confirmed by elevated plasma levels of glucocerebrosidases. Conclusion: Gaucher’s disease is a rare metabolic disease of the bone which may mimic a primary bone tumor or metastasis. A step-wise meticulous approach with biopsy and elevated plasma levels of glucocerebrosidase helps establish the diagnosis. Once must have a high index of suspicion for Gaucher’s disease in an adult with multiple osteolytic lesions without any significant past medical and surgical history.