Malignant Potential of Endobronchial Glomangioma: A Case Report of an Unpredictable Diagnosis and Unexpected Outcome.

Background: Glomus tumors are neoplasms typically arising from the glomus body in the skin or subcutaneous tissue. They are rarely found in visceral organs, including the respiratory tract. Glomangioma is a vascular variant, and its pulmonary subtype is challenging to predict due to the absence of specific symptoms or distinctive radiological features. While most glomangiomas are benign, in rare cases, they can exhibit aggressive clinical and histological characteristics, leading to severe conditions. Case presentation: We report a case of malignant endobronchial glomangioma in a patient presenting with hemoptysis and atypical chest pain. Chest computed tomography (CT) revealed an endobronchial tumor in the left distal main stem bronchus, partially obstructing the lumen. The patient was clinically diagnosed with suspected metastatic lung cancer and was scheduled for bronchoscopy and biopsy. During the biopsy, a rounded, bulging mass was partially removed; however, significant intraoperative bleeding occurred, necessitating the formation of an intentional blood clot. Ongoing bleeding and airway necessitated emergency pneumonectomy after 24 hours. Unfortunately, the patient experienced cardiac arrest postoperatively and died. Pathological examination revealed a mass with prominent vascular components lined by endothelial cells, with immunohistochemistry showing positivity only for smooth muscle actin, supporting the diagnosis of glomangioma. Conclusion: Although difficult to diagnose clinically prior to biopsy, malignant endobronchial glomangioma should be considered in certain patient populations due to its specific outcomes and complications. Preventive measures and targeted interventions should be implemented to manage iatrogenic bleeding complications associated with biopsy procedures.