Osteoblastoma of the Hyoid Bone

Abstract

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.

Osteoma of the stylohyoid chain: A rare presentation in a CBCT study

“…Benign tumors arising from the hyoid bone are uncommon, and there have been a few cases of chondroma, osteochondroma, giant cell tumor, and osteoblastoma derived from the hyoid bone. 17 18 19 20 21 A giant cell tumor presents an enlarged soft tissue mass with proliferative signs of bone destruction, often displacing the surrounding structures. 17 18 In chondroma, osteochondroma, and osteoblastoma, multiple spots of calcification in the tumor matrix are a distinct characteristic for identifying these conditions.…”

Chondrosarcoma of the hyoid bone: A diagnostic pitfall in the submandibular region

“…Furthermore, the possibility of the presence of a CS variant (mesenchymal, myxoid, clear cell or dedifferentiated CS) could even impose greater diagnostic difficulty, with some of them previously reported on the hyoid bone . Osteoblastoma is another bone tumor, exceedingly rare in this site, that despite different cytological features (on FNAC the differential diagnosis is with osteoid osteoma and osteosarcoma) can be radiologicaly mistaken as a CS. A unique case of condroblastoma of the hyoid bone has also been described, further adding another potential differential diagnosis, where the presence of osteoclast‐type giant cells and mononuclear cells with reniform nuclei with grooves or folds are the most distinct cytological features.…”

Chondrosarcoma of the hyoid bone: Case report and review of current management options

“…Histologically they consist of bland cartilage and differentiation from a low‐grade chondrosarcoma can be extremely difficult. Osteosarcomas, the most common primary bone tumor, may cause periosteal thickening, but can be differentiated from chondrosarcomas based on a different matrix calcification pattern on CT. Osteoblastomas of the hyoid bone are exceedingly rare, but may be mistaken for chondrosarcomas on imaging because of their similar calcified matrixes and their expansile appearances …”