Scapular osteochondrolipoma: Imaging features with pathological correlation

Abstract

Osteochondrolipoma is an extremely rare histological variant of lipoma with osseous and cartilaginous differentiation. The present study reports an unusual case of an osteochondrolipoma occurring in the left scapular region of a 49-year-old male. The physical examination revealed a 3-cm, hard, non-tender and minimally mobile mass. Plain radiography revealed a faintly ossified soft-tissue mass without evidence of bone erosion. Computed tomography (CT) confirmed the presence of a lesion and the normal appearance of the scapula. Magnetic resonance imaging (MRI) showed a well-circumscribed subcutaneous mass with an almost homogeneous high signal intensity on the T1- and T2-weighted sequences. Contrast-enhanced fat-suppressed T1-weighted sequences demonstrated a faint peripheral and septal enhancement of the mass. A marginal excision of the tumor was performed. Histologically, the tumor was predominantly composed of mature adipocytes mixed with thin trabeculae of mature bone. In addition, small amounts of mature hyaline cartilage and osteoid were identified in the periphery of the lesion. Based on these findings, the tumor was diagnosed as an osteochondrolipoma. The patient demonstrated no evidence of local recurrence within six months of follow-up. Although rare, osteochondrolipoma should be considered as a differential diagnosis of a well-defined, calcified/ossified, subcutaneous mass in the scapular region.