Phosphaturic mesenchymal tumor of the skull base presenting with tumor-induced osteomalacia and multiple fractures: a case report

This case reports a rare disease in which the clinical symptoms are completely inconsistent with the primary site. As the occurrence of this disease is partly rare, the challenges in the diagnosis of phosphaturic mesenchymal tumors are discussed. It also provides a new clinical treatment option, that is, the combined treatment with anlotinib capsules after surgery and the long-term follow-up to observe the effect of the combined treatment. A 27-year-old Chinese woman presented with generalized pain and multiple fractures for 2 years. The present case was initially thought to be hematogenous and involved a malignant predisposition. After initial positron emission tomography-computed tomography imaging, endoscopic resection of the lesion was performed, and a biopsy confirmed the diagnosis of phosphaturic mesenchymal tumor. Following pathological confirmation, the patient was treated with anlotinib capsules. Post-treatment, the patient regained the ability to walk. The patient was monitored for 2 years, during which time no recurrence was observed. Phosphaturic mesenchymal tumors include rare cranial base neoplasms that are often overlooked due to their nonspecific symptoms. Accurate diagnosis requires a comprehensive assessment, encompassing systemic evaluation, laboratory tests, imaging studies, and microscopic examination. This case demonstrates the innovative use of anlotinib capsules in the treatment of PMTs. After 2 years, no recurrence was observed, and the patient returned to normal life. Effective management of this condition necessitates a multidisciplinary approach involving otolaryngologists, radiologists, nuclear medicine specialists, and pathologists.