Very rare myoepithelial carcinoma occurred in the humerus: a case report

Introduction: Myoepithelial carcinoma (MEC) most frequently arises in the salivary glands; intraosseous disease is exceptionally rare. Early recognition is challenging, and evidence‑based management is lacking. Case presentation: A 16‑year‑old Japanese male presented with left shoulder pain. A proximal humeral lesion was monitored using radiographs over a 2-year period, after which an urgent biopsy identified MEC. He received two cycles of paclitaxel (200 mg/m 2 ) plus carboplatin (AUC 5) as neoadjuvant chemotherapy, followed by wide resection and vascularized fibular reconstruction. Margins were negative. Discussion: Despite preoperative and postoperative adjuvant chemotherapy, the patient developed lung metastasis 1 year after surgery and died 6 months later. Delayed biopsy may have contributed to disease progression. Current literature recommends early biopsy, extensive resection, and consideration of molecular targeted therapy. Conclusion: Bone MEC is aggressive; prompt histological diagnosis and multidisciplinary treatment are crucial to improve prognosis.