Surgical and biochemical outcomes of phosphaturic mesenchymal tumors causing tumor-induced osteomalacia in the head and neck region

• Published in: Oral and maxillofacial surgery cases 2023-12, Vol.9 (4), p.100335, Article 100335
• Main Authors: Tsuda, Yusuke, Yasunaga, Yoichi, Abe, Masanobu, Hoshi, Kazuto, Ito, Nobuaki, Kondo, Kenji, Okajima, Koichi, Zhang, Liuzhe, Kato, Hajime, Hidaka, Naoko, Tanaka, Sakae, Kobayashi, Hiroshi
• Format: Article
• Language: English
• Subjects: Biochemical outcomes; Head and neck; Phosphaturic mesenchymal tumors; Surgical outcomes; Tumor-induced osteomalacia
• ISSN: 2214-5419; 2214-5419
• DOI: 10.1016/j.omsc.2023.100335

We aimed to report the surgical outcomes of phosphaturic mesenchymal tumors causing tumor-induced osteomalacia in the head and neck. This study analyzed nine patients who underwent surgical excision of phosphaturic mesenchymal tumors in the head and neck region. The primary sites were two in the maxilla and ethmoid sinus, and one in the intracranial, skull, parotid gland, maxillary sinus, and nasal cavity in each patient. Outcomes were compared with those in the extremities and trunk (n = 32). Five of nine patients (56%) developed residual disease/local recurrence associated with low serum phosphate level after initial surgical excision. At the last follow-up, the biochemical parameters were normalized in four of the five patients after re-excision without any medication. The local recurrence/residual disease risk was significantly higher for the head and neck compared with the extremities and trunk (56% vs. 25%, p = 0.048). The rate of remission (normalized serum phosphate without medication) at final follow-up was similar in both groups after re-excision (head and neck vs. extremities and trunk, 86% vs. 73%, p = 0.827). Phosphaturic mesenchymal tumor resection in the head and neck region was challenging because of its complex anatomy and proximity to the brain or other crucial organs, which was associated with high local recurrence/residual disease rate. However, biological remission was achieved in the majority of the patients after re-excision. •Tumor-induced osteomalacia is a rare and underreported condition because treating clinicians are unaware of its clinical characteristics. We highlighted our experience with Tumor-induced osteomalacia cases in the head and neck regions.•Phosphaturic mesenchymal tumor resection in the head and neck region was associated with high local recurrence/residual disease rate. However, biological remission was achieved in the majority of the patients after re-excision.•Before definitive resection, surgeons should discuss with their patients the difficulty of obtaining clear margins due to the complex anatomy.