Intraosseous hibernoma: a rare adipocytic bone tumour.
Hibernoma is a benign adipose tumour that contains foetal brown fat cells. We report a case of hibernoma arising in the left ischium of a 65-year-old female with a past history of ovarian carcinoma. The patient presented with a relatively short history of left sacral/hip pain. Radiologically, the lesion, which was large (5 cm) and sclerotic, had been stable for a number of years. Histologically, it was composed mainly of plump cells with foamy, multivacuolated cytoplasm. These cells showed no reaction for epithelial, melanoma or leucocyte markers but expressed FABP4/aP2 and S100, indicating that they were brown fat cells. There was no mitotic activity or nuclear pleomorphism and the lesion was diagnosed as a benign intraosseous hibernoma (IOH). IOH is a recently identified benign adipocytic lesion that presents typically as a sclerotic bone lesion. It has characteristic morphological and immunophenotypic features and should be regarded as a discrete primary bone tumour that needs to be distinguished from metastatic carcinoma/melanoma, chondrosarcoma and metabolic storage diseases containing numerous foamy macrophages.
Department of Radiology, Nuffield Orthopaedic Centre, Oxford, UK.
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M
Vlychou
Department of Radiology, Nuffield Orthopaedic Centre, Oxford, UK.
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J
Teh
Orthopaedic Surgery, Nuffield Orthopaedic Centre, Oxford, UK.
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D
Whitwell
Department of Pathology, Nuffield Orthopaedic Centre, Oxford, UK. nick.athanasou@ndorms.ox.ac.uk.|Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Nuffield Orthopaedic Centre, University of Oxford, Oxford, OX3 7HE, UK. nick.athanasou@ndorms.ox.ac.uk.
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Athanasou
D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008067:Lipoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D035583:Rare Diseases / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed / Q000379:methods*
Adipose tissue; Bone tumour; Hibernoma; Pelvis