INTRODUCTION: Unusual locations of glomus tumors, including the mediastinum and trachea, have been reported and can be mistaken with carcinoid tumors.
CASE PRESENTATION: A 48-year-old white male, nonsmoker, presented with a three month history of mild hemoptysis, cough, and a left forearm subcutaneous mass. Past medical history was remarkable for a tracheal carcinoid tumor which was resected 17 years ago. Physical examination revealed a left forearm soft tissue mass of about 2 x 2 cm which was nontender and without overlying skin changes. The remainder of the exam was normal. Serum chemistries and CBC were within normal limits. Chest CT demonstrated a polypoid lesion in the distal trachea and precarinal region. Bronchoscopy showed a polypoid mass extending from the anterior tracheal wall just above the main carina resulting in 80% occlusion of the right mainstem bronchus take-off and 70% occlusion of the left mainstem bronchus take-off (figure 1). The tracheal mass was resected with electrocautery using a snare and blunt probe achieving 100% patency. Pathology was initially read as showing a carcinoid tumor. Biopsy of the forearm mass revealed a tumor composed of nests of large, eosinophilic cells deposited in a collagenous and myxoid matrix with immunohistochemistry positive for muscle specific actin and smooth muscle actin and negative for cytokeratin AE1/3, chromogranin and synaptophysin. This was consistent with a glomus tumor. Subsequent mmunohistochemical staining of the tracheal tumor demonstrated similar findings and was felt to also be a glomus tumor. At bronchoscopy three months later there was abnormal mucosa that was treated with electrocautery followed by radiotherapy. Six months later there was no evidence of endotracheal recurrence (figure 2).
DISCUSSIONS: Glomus tumors are benign neoplasms derived of glomus cells that resemble the modified smooth muscle cells of the normal glomus body. Glomus tumors typically involve the skin of the extremities, with subungual region of the finger being the most common site. This tumor is extremely rare in the mediastinum and lung. Within the respiratory tract, the trachea is the most frequent site of involvement, with only 16 cases reported in the literature. All patients had tumor arising from the posterior membranous wall of the trachea, except in our case where the tumor was arising from the anterior wall. None of the tumors were metastatic although our patient had a concomitant glomus tumor in his left forearm. Histologically, glomus tumors consist of medium sized cells with round, regular nuclei and eosinophilic cytoplasm with nested pattern that surround vascular channels. Glomus tumors are uniformly positive for vimentin, smooth muscle actin and variable for desmin. They are negative for cytokeratin, chromogranin and synaptophysin. One major differential diagnosis of a glomus tumor is a carcinoid tumor. Carcinoid tumors have a coarsely granular or salt and pepper chromatin, do not have a prominent vascular channels, and are positive for cytokeratin and neuroendocrine markers such as chromogranin and synaptophysin. Most peripheral and visceral glomus tumors are histologically and clinically benign, however atypical types do exist and fatal cases have been reported. The recommended treatment for glomus tumor of the trachea is sleeve resection with primary reconstruction which is curative and requires no adjuvant treatment. Bronchoscopic laser resection with adjuvant radiotherapy has been used with good results. In our patient, we utilized electrocautery and radiotherapy with no evidence of recurrence so far.
CONCLUSION: Glomus tumors should be included in the differential diagnosis of tracheobronchial lesions and are often mistaken with carcinoid tumors. Bronchoscopic resection and adjuvant radiotherapy is a valid treatment option. To the best of our knowledge, this is the first patient reported with concomitant tracheal and subcutaneous glomus tumors.
DISCLOSURE: Sebastian Fernandez-Bussy, None.