Fig. 1

Fig. 2

Majority of the thymomas are found in the anterior mediastinum. Occasionally, some have been found in the neck, pulmonary hilus, posterior mediastinum and cardiophrenic angles.4 We present here a rare case, wherein, the thymoma presented with a lump in the neck and myasthenic symptoms. Ectopic thymoma in the neck incidence varies from around 4% of the cases.

Case Report

A 45 year male presented to us with insidious onset and progressive symptoms of drooping of eyelids; dysphagia and lump in the right side neck since 4 months. On clinical evaluation, he had bilateral ptosis; a nasal twang to his speech and a firm non-mobile lump in right paratracheal region 4 cm in transverse diameter. The lower limit of the lump was not palpable. The lump did not move on deglutition or come into the region of the neck on coughing. Neck nodes were not palpable. With the above clinical findings, a differential diagnosis of Ectopic Thymoma with Myasthenia Gravis; Thyroid tumour and Parathyroid tumour was suspected. On further investigating the patient, X-ray chest and neck showed a paratracheal opacity. MRI of the chest and neck revealed a discrete mass inferior to the right lobe of the thyroid in the tracheo-oesophageal groove extending into the superior mediastinum and behind the superior vena cava. There was no infiltration into the wall of the trachea or the oesophagus (Figs. 1 and 2). The endocrinological and routine workup was normal. The CT guided FNAC was suggestive of Thymoma. Patient was put on Tab. Pyridostigmine 60 mg three times a day.

After intensive chest physiotherapy patient was taken up for surgical exploration. At the root of the neck, a transverse right supraclavicular incision was taken 1.5 cm above the clavicle and suprasternal notch. The inferior pole of the right lobe of the thyroid gland was exposed. Mass was found to be separate from the thyroid. It was separated from the trachea and the oesophagus. It was found to be infiltrating the superficial layer of the oesophagus on the right side. Excision of the oesophageal muscle wall was done keeping the mucosa intact with resuturing of the muscle layer. The mediastinal portion of the mass behind the SVC was delivered in the neck. Complete naked eye clearance was done.

Postoperatively, the patient developed an oesophago-cutaneous fistula, which healed by conservative management, by not allowing the patient to take anything orally and Ryles tube aspiration for 10 days. Patient’s Myasthenic symptoms worsened (Myasthenic Crisis) after one week for which Pyridostigmine dose was stepped up. Patient was discharged after 15 days. He reported during follow up with increased salivation and dysphagia due to increased dose of Pyridostigmine (Patient was in Cholinergic Crisis). Hence, a steroid, Tab Prednisolone 40 mg OD, was introduced, along with decrease in the dose of Pyridostigmine. Steroid was gradually tapered off in the subsequent follow up period.

The final histopathology report suggested Invasive Thymoma Stage III Masaoka and Colleagues.5 Considering the invasive nature of the thymoma, patient was given postoperative Radiotherapy.

Thymus gland is a gland situated in the fibrofatty tissue of the anterior mediastinum. Approximately, 75% of thymomas are sited in the anterior mediastinum. 15% are situated in the anterior and superior mediastinum. 6% are found in the superior mediastinum and 4% in the neck and posterior mediastinum, which is a rare site.8 This is due to the arrest in the downward descent of the thymus gland during the development of the embryo. Although, the relationship between Myasthenia Gravis (MG) and thymoma remains illdefined, the recognition of the thymomas has recently increased, since a more aggressive surgical approach to patients with MG has demonstrated that many patients with this disorder harbour occult neoplasm.3 An accurate localization and diagnosis of the thymic tissue at various sites with the help of CT scan and MRI has proved a stepping stone.6 Associated syndromes like MG affect the survival by increasing the morbidity.1,2 In a study conducted by M Ashour of the Khalid Hospital, Riyadh, showed that patients with MG and Ectopic Thymoma had a poor outcome, as only 13% had complete remission as compared to patients of MG without Ectopic Thymoma who had a remission of 48%.7 Thus the presence of an Ectopic thymic tissue not only modifies some of the clinical parameters of MG, but also could serve as a prognostic indicator predicting the outcome of the operation.