[Primary tracheal malignant glomus tumor with lung metastasis diagnosed by pathological analysis: a case report and literature review].

To study the clinical manifestations, pathological features, diagnosis, differential diagnosis, treatment and prognosis of primary tracheobronchial or pulmonary malignant glomus tumor (MGT). A case of primary tracheal MGT with lung metastasis diagnosed by pathological analysis admitted to Affiliated Shantou Hospital of Sun Yat-sen University in May. 2015 was analyzed, and the related literatures were reviewed. We searched databases including PubMed, Embase, Ovid, Cochrane, Wanfang and Chinese National Knowledge infrastructure (CNKI), using the keyword "tracheal or bronchial or pulmonary malignant glomus tumor" from Jan. 1975 to Dec. 2016. A 47 year-old male patient was admitted to the hospital because of cough, chest tightness and shortness of breath for 3 days. The chest CT showed a soft tissue mass with a diameter of 2.5 cm in the lower tracheal segment, and the lumen was narrowed. Meanwhile, multiple nodular opacities were shown in both lungs. The admission diagnosis was thyroid cancer with multiple metastases of lung. Electronic bronchoscopic airway tumor ablation and cryotherapy were performed, and then the biopsy of the tumor was conducted and the pathological study confirmed the diagnosis of primary tracheal MGT. After 1 month, the tracheal tumor recurred. Then, electronic bronchoscopic airway tumor ablation and cryotherapy were performed again. The patient declined further therapy such as radiotherapy or chemotherapy and died one month later. A total of 14 literatures including 15 cases were retrieved from databases. In addition of this case, a total of 16 cases were analyzed, including 9 males, 7 females. Age of onset ranged from 9 to 74 years, and the average age was 49 years. These patients' chest CT showed airway mass or lung space occupying lesions, and the clinical manifestations were nonspecific. Primary MGT in trachea, bronchus or lung is a rare disease, which is easy to be misdiagnosed or to miss diagnosis. The final diagnosis depends on pathological morphology, and the main treatment is lobectomy or tracheal segment resection surgery. Due to its high invasiveness, local recurrence and metastasis may occur easily. The primary MGT in trachea, bronchus or lung is of poor prognosis.