Locally infiltrative glomus tumor of the bronchus: a case report

We report a glomus tumor of the bronchus that showed invasion of the neural area and extrabronchial extension without significant histological malignancy. The patient was a male in his late 30s with the chief complaint being hemosputum. CT revealed a nodal shadow 15 mm in diameter in the right bronchus intermedius. An irregularly protruding lesion on the tumor surface was observed by bronchoscopy immediately under the second carina in the right truncus intermedius, but could not be diagnosed because of bleeding. Sleeve lobectomy of the right upper lobe was performed, since carcinoid tumor was suspected in open chest biopsy and intraoperative frozen section diagnosis. A solid growth of spherical and cubic uniform cells with a clear eosinophilic cytoplasm and spherical nuclei was observed. Immunohistochemistry was positive for α-smooth muscle actin and type IV collagen, weakly positive for synaptophysin, and negative for keratin, neural cell adhesion molecule, chromogranin A, desmin, CD34, and S100, leading to a diagnosis of glomus tumor. Neuroinvasion and extrabronchial tumor extension were observed, but an atypical cytology, bleeding, or necrosis was found histologically. This is the first description of infiltrative glomus tumor of the bronchus.