SUMMARY: Osteoblastoma is a rare bone tumor that usually affects the vertebrae. We present the first known case of osteoblastoma arising in the hyoid bone, in a patient who presented with a neck mass and dysphagia. The radiographic appearance of the tumor is similar to that of low-grade chondrosarcoma, with well-defined expansion of the bone and central chondroid matrix.
ABBREVIATIONS:NSAIDs ϭ nonsteroidal anti-inflammatory drugs S olid primary tumors of the hyoid bone are exceedingly rare. Reported cases have included chondrosarcoma, plasmacytoma, osteosarcoma, giant cell tumor, aneurysmal bone cyst, and benign osteoma.1 Patients with hyoid bone tumors usually present with dysphagia and may have a palpable neck mass. The goal of imaging is to distinguish benign from malignant causes and to assist in surgical planning.Osteoblastoma is a rare benign bone tumor first described in 1956. In the head and neck, osteoblastoma may arise in the maxilla, mandible, temporal bone, and, very rarely, in the larynx.2 Surgical excision, when feasible, is usually curative. We present the first known case of an osteoblastoma arising in the hyoid bone.
Case ReportA healthy 51-year-old man presented with a mass in the left side of the neck, which he had noticed 3 weeks earlier. He reported pain in the contralateral neck for the past 5 years and mild dysphagia of recent onset, but his voice was unchanged. Thirty years ago the patient had undergone chemoradiation and surgery for a fibrosarcoma in the soft tissues in his posterior neck. Physical examination was remarkable for a hard nontender left-sided neck mass at the level of the hyoid bone. This mass was freely mobile and moved up and down with swallowing. The overlying skin was intact. Flexible transnasal laryngoscopy showed indentation of the left lateral pharyngeal wall at the level of the hyoid bone.CT revealed a 3-cm well-defined spheric mass with a calcified ring and a partially calcified central matrix, arising within the left hyoid bone, causing extrinsic compression of the hypopharynx (Fig 1). On the basis of these imaging features, a diagnosis of low-grade chondrosarcoma of the hyoid bone was proposed. Differential considerations included bony tumors such as osteosarcoma, enchondroma, and ossifying fibroma.The patient underwent resection of the left hyoid bone, from which he recovered uneventfully. The pathologic diagnosis was a 3-cm hyoid osteoblastoma with a secondary aneurysmal bone cyst component. Focally, the tumor broke through the cortex into the adjacent soft tissue, but the surgical margin in this area appeared free. A specimen radiograph showed the internal calcified matrix in greater detail (Fig 2).
DiscussionSolid primary tumors of the hyoid bone are exceedingly rare, and reported cases have included plasmacytoma, osteosarcoma, giant cell tumor, aneurysmal bone cyst, osteoma, and chondrosarcoma.