Tracheal bronchus is an abnormal bronchial branch, arising directly from the lateral wall of the trachea. They can be located at any point but are generally found within 2 cm above the carina, in the right lateral wall.1–4 Tracheal bronchi are rare congenital anomalies with a prevalence of 0.1% to 2% in the bronchographic and bronchoscopic studies. These bronchi are described as “supernumerary” when they coexist with a normal branching of the upper lobe bronchus and as “displaced” when 1 branch of the upper lobe is missing. The displaced type is more frequent.3,4
These aberrant bronchi are usually asymptomatic, but symptoms may occur in approximately 25% of the patients,3 mainly as a result of relatively poor local drainage. There are some important implications, particularly during endotracheal intubation when the endotracheal tube may occlude the lumen of the tracheal bronchus or an inadvertent intubation of the anomalous lobe takes place. In the literature, these aberrant bronchi have been described with presenting manifestations as recurrent local infections, persistent cough, stridor, or hemoptysis.3–5 Tumor development in tracheal bronchi is known with a few cases reported in the literature.1–3,5–7 To our knowledge, this is the first case of a metachronous tumor involving a tracheal bronchus.
A 53-year-old man, with smoking history of 60 pack years (1.5 packs of cigarettes every day for 40 y) and alcohol abuse, was referred to otorhinolaryngology assessment for odynophagia and dysphonia since the beginning of 2010. A diagnosis of squamous cell carcinoma of the right pyriform sinus was made in April 2010. The patient was submitted to hemilaryngectomy and the histologic examination revealed the lesion to be a T2N0Mx tumor.
A chest computerized tomography scan performed in January 2011 (Fig. 1) for hemoptysis revealed a 5.3-cm mass involving the right upper lobe and the latter being ventilated by a tracheal bronchus. Signs of mediastinal invasion were present and multiple smaller nodules were also scattered in both the lung fields. A flexible bronchoscopy performed in February 2011 revealed a displaced tracheal bronchus in the right lateral wall of the trachea above the carina (B1). The remaining right upper lobe (B2+B3) presented edema of the mucosa. The bronchial lavage performed in the tracheal bronchus was diagnostic of squamous cell carcinoma (stage IV); however, no endobronchial lesion involving the tracheal bronchus was noticed at this stage.
Given the stage of the supraglottic tumor (stage II), the absence of local recurrence and existence of a tumor mass on the right upper lobe significantly larger than the other lung lesions, it was assumed to be a second primary of the lung origin. The patient completed 6 cycles of carboplatin and gemcitabina in June 2011 with local disease control until October 2011. In November 2011, a repeat bronchoscopy (Fig. 2) was performed for hemoptysis that revealed near-total obstruction of the tracheal bronchus with a pedunculated tumor mass, which was eventually diagnosed as a squamous cell carcinoma.
The differential diagnosis between lung metastases of the larynx tumor and a second primary tumor is not clear, whether they have the same histologic type and there are multiple pulmonary lesions.
A metachronous tumor is a second primary diagnosed >6 months after the diagnosis of the index tumor.8 Second primary malignancies are a particular problem for head and neck cancer patients. The reported overall incidence, which is higher in smokers and alcohol abusers, ranges between 5% and 30%.9
In contrast, the incidence of distant metastases in subjects with head and neck squamous cell carcinoma is relatively low, 5% in patients with locoregional control.10
Although there is a lack of evidence to establish whether a tracheal bronchus is more susceptible to malignant neoplasias, there are 14 cases of lung cancer associated with tracheal bronchi in the literature.1–3,5–7 Our case is the first case reported in Portugal and, to our knowledge, the first case of a metachronous tumor in a tracheal bronchus.
Our case highlights the fact that the bronchoscopist needs to be aware of endobronchial anomalies and their implications.
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