Ectopic Cervical Thymoma Excised through a Transcervical Approach Combined with Video-assisted Thoracoscopic Surgery: A Case Report

Ectopic cervical thymoma with myasthenia gravis: a rare association

Thymic masses are one of the most common tumors in the anterior mediastinum. Nevertheless, because the thymus originates in the third and fourth pharyngeal pouches and descends into the anterior mediastinum, ectopic thymic tissue may be found anywhere from the angle of the mandible to the superior mediastinum. Ectopic cervical thymoma (ECT) is an extremely rare tumor that originates from ectopic thymic tissue trapped during the migration of the embryonic thymus and is often misdiagnosed as a thyroid tumor or other neck masses. Herein, we report an unusual case of ectopic cervical thymoma associated to myasthenia gravis (MG).

Ectopic thymoma: report of 2 cases and review of the literature

In this report, we present two cases of ectopic thymoma, aiming to explore the clinicopathologic features, diagnosis, and differential diagnosis of ectopic thymoma. Case 1 was a female 56-years-old. For 6 months' time, there was no obvious cause of cough, expectoration, chest tightness, or asthma with chest pain. PET-CT showed a right middle lung and lower lung mass with increased FDG metabolism. Postoperative pathology was diagnosed as right middle and lower lung ectopic thymoma, type B2, invading the chest wall. Case 2 was a male of 54-years-old. By physical examination the right chest cavity had a mass present for 1 week and he was admitted to hospital. Postoperative pathology was diagnosed as right thoracic ectopic thymoma, type AB. No recurrence has been found to in the follow-up of these two patients. In conclusion, ectopic thymoma occurs outside the anterior mediastinum. It is rare, the clinical symptoms are not typical, and pre-operative diagnosis is difficult. It is easily misdiagnosed as other diseases. Surgical treatment is the best method. According to the pathologic type and invasion of the tumor, radiotherapy may be considered.

[Ectopic thymic tissue and ectopic thymic tumors]

Ectopic thymic tissue outside its core position in the antero-superior mediastinum is quite common owing to the complexity of embryonal thymus development, whereby reported prevalence values (1 to 90%) are heavily dependent on the method of investigation and the intensity of the workup. The debated prevalence and relevance of ectopic thymic tissue and its accessibility underlie the ongoing discussion whether modern, minimally invasive thymectomy strategies can match the proven benefit of the radical transsternal thymectomy procedure for the treatment of Myasthenia gravis. In this context, the following article covers the etiology, prevalence, and location of normal-looking, reactive, and neoplastic ectopic thymic tissue. Furthermore, ectopic tissues and tumors inside or adjacent to the thymus are mentioned.

An Unusual Invasive Ectopic Thymoma in the Thyroid and Anterior Mediastinum

An 81-year-old woman with a 2-year history of dysphagia detected a cervical mass. Computed tomography showed a thyroid tumor extending through the superior and anterior mediastinum. Analysis of an incisional biopsy specimen revealed a thymoma. Total resection of the thyroid and mediastinal tumor was performed. The thymoma invaded the anterior tracheal wall and left brachiocephalic vein. Pathologic examination revealed thymoma type B1 concomitant with B2 and B3 (World Health Organization classification), Masaoka IVb, and T3 N2 M0-IVb, with cervical lymph node metastasis. Clinicians must be cautious during radical operations for invasive ectopic thymomas.

Ectopic thymoma managed by neck dissection & video-assisted thoracoscopic thymectomy

Ectopic thymoma in the neck is a rare phenomenon, with fewer than 20 cases reported worldwide. Evidence for management of ectopic thymoma comes from literature for mediastinal thymoma despite clinical features that distinguish the two. Here we present a case of a 31-year-old female with an asymptomatic neck mass who was found to have an ectopic cervical thymoma with concomitant mediastinal thymic hyperplasia. The decision was made to perform a left-sided neck dissection and a video-assisted thoracoscopic surgery (VATS) thymectomy. We suggest that this approach be considered for a minimally invasive management of this rare but important condition.

The spectrum of ectopic thymomas

Thymomas are rare tumors that usually manifest in the anterosuperior mediastinum. Occasionally, thymomas may also originate from ectopically dispersed thymic tissue and can arise in locations such as the neck, lung, or pleura or other locations in the thoracic cavity. The occurrence of thymomas in these ectopic locations can cause substantial diagnostic difficulty as the entity is almost never included in the differential diagnosis and its biphasic morphology can cause further complications during the diagnostic process. In this review, we summarize the clinical and pathological spectrum of ectopic thymomas and discuss the histogenesis, treatment, and prognosis of these extraordinary tumors.