Thymomas are epithelial tumors arising from thymic tissue and represent the most common primary mediastinal neoplasm.

They originate embryologically from the third pharyngeal pouch and descend to the anterior mediastinum between the 6th and 8th weeks of gestation. During this migration, ectopic thymic tissue may persist in atypical locations, giving rise to ectopic thymomas in the cervical region, posterior mediastinum, lung, or pleura. A paratracheal location is exceptionally rare, with only isolated cases reported in the literature, making preoperative diagnosis challenging and potentially leading to misinterpretation [1,2].

We report the case of a 60-year-old woman with a right paratracheal ectopic type A thymoma treated using a robotic approach.

The patient was an active smoker with no relevant past medical history and was being evaluated for a respiratory superinfection. Computed tomography (CT) revealed a 37-mm×26-mm solid nodule in the right paratracheal region. Positron emission tomography/computed tomography (PET/CT) demonstrated hypermetabolic uptake (SUVmax, 4.16), suggestive of malignancy (Fig. 1).

Fig. 1.

Ectopic thymoma located in the right paratracheal region. (A) CT scan showing a 37mm×26mm well-defined solid oval lesion. (B) PET/CT demonstrating nonspecific hypermetabolic uptake (SUVmax, 4.16). (C) Tumor at the right cavotracheal confluence. (D) Encapsulated specimen measuring 4.5cm×4cm.

Following multidisciplinary discussion, endobronchial ultrasound (EBUS) was performed but was inconclusive. Diagnostic mediastinoscopy was subsequently performed, revealing a monomorphic spindle cell neoplasm with nonspecific myoepithelial differentiation. Given these findings, surgical resection was indicated.

The procedure was performed using a minimally invasive approach with 4 ports, with the patient in the left lateral decubitus position, assisted by the da Vinci robotic system. The 3–4-cm tumor was located at the right cavotracheal confluence. After mediastinal pleural dissection, complete resection was achieved, with careful separation from the superior vena cava, trachea, and supra-aortic vessels, preserving the phrenic and vagus nerves.

The surgical specimen consisted of an encapsulated lesion measuring 4.5cm×4cm. Histopathological examination confirmed a World Health Organization type A thymoma, Masaoka stage I [3].

The postoperative course was uneventful, and the patient was discharged on postoperative day 3. At follow-up, she remained asymptomatic, with no need for adjuvant therapy.

The paratracheal location of thymomas is extremely rare, with only 13 cases reported in the literature. Imaging findings are nonspecific, which often leads to confusion with mediastinal lymphadenopathy. Moreover, diagnostic procedures such as EBUS or mediastinoscopy may be inconclusive, reinforcing the role of surgical resection as both a diagnostic and therapeutic approach [2,4].

In this case, robot-assisted minimally invasive surgery provided enhanced precision, particularly in deep mediastinal planes, and improved 3-dimensional visualization, facilitating complete resection while preserving adjacent vital structures [5].