Metachronous head and neck osteosarcoma in an elderly patient: A rare case report with prior verrucous carcinoma

Head and neck osteosarcoma is a rare malignancy, accounting for 6%-10% of all osteosarcomas, and typically affects younger individuals. Its occurrence as a metachronous tumor in elderly patients, particularly after radiotherapy, is exceedingly uncommon.

A 91-year-old man with a history of right lateral tongue verrucous carcinoma treated by surgery and adjuvant radiotherapy (50 Gy) in 2006 presented in 2024 with progressive hoarseness and dysphagia for 6 months.

Clinical examination revealed a firm neck mass. Laryngeal biopsy showed benign keratosis, while core needle biopsy demonstrated a malignant mesenchymal tumor with osteoid production. Immunohistochemistry showed negative cytokeratin and p63, and Ki-67 positivity in 20% of cells, confirming osteosarcoma. Imaging revealed a calcified lesion involving the hyoid, thyroid cartilage, and tongue base, consistent with metachronous head and neck osteosarcoma.

Due to advanced age and comorbidities (hypertension and diabetes), palliative radiotherapy (30 Gy in 15 fractions) was administered. Surgery and chemotherapy were avoided because of frailty and limited benefit.

The patient tolerated treatment well, achieving partial symptom relief without major toxicity. Long-term follow-up continues with a focus on quality of life.

This case highlights the diagnostic challenges of secondary head and neck osteosarcoma following radiotherapy and the importance of long-term surveillance in elderly patients. Individualized management balancing treatment efficacy and tolerability is essential in geriatric oncology.