|Year : 2022 | Volume
| Issue : 4 | Page : 282-284
A giant posterior mediastinal goiter
Ajin Anto1, Surjeet Dwivedi1, Raj Mohan1, Rakesh Jha2
1 Department of Surgery, Command Hospital, Air Force, Bangalore, Karnataka, India
2 Department of Surgery, Indian Navy Hospital, Mumbai, India
|Date of Submission||10-Aug-2022|
|Date of Decision||09-Sep-2022|
|Date of Acceptance||29-Sep-2022|
|Date of Web Publication||17-Mar-2023|
Department of Surgery, Command Hospital, Air Force, Bengaluru, Karnataka
Source of Support: None, Conflict of Interest: None
Goiter is defined as abnormal (either nodular or diffuse) growth of the thyroid gland. The normal thyroid gland is located in neck, caudal to larynx in anterolateral portion of the trachea. Intrathoracic goiter, defined as growth of more than 50% of the thyroid gland below the thoracic operculum, mostly located in anterior mediastinum and is seen in only 8%–15% of all goiters. Posterior mediastinal goiters (PMGs) are rare and accounts for only 2% of intrathoracic goiters. Patients usually present with a cervical mass and local pressure symptoms due to tracheal, esophageal, or superior vena cava compression. The diagnosis is established by chest X-ray, computed tomography scan, and fine-needle aspiration cytology. A combined cervicothoracic approach is the procedure of choice as it provides easy access, better visualization, and optimal control of blood vessels. We, hereby, describe a case of giant PMG, which was managed successfully at our center.
Keywords: Cervicothoracic incision, intrathoracic goiter, posterior mediastinal goiter, retrosternal goiter
|How to cite this article:|
Anto A, Dwivedi S, Mohan R, Jha R. A giant posterior mediastinal goiter. CHRISMED J Health Res 2022;9:282-4
| Introduction|| |
Intrathoracic or retrosternal goiter was first described by Haller in 1749. Since then, lots of controversies persisted regarding its definition. At present, the most widely accepted definition of intrathoracic goiter is presence of more than 50% of the thyroid gland below the thoracic inlet. Posterior mediastinal goiters (PMGs) are very rare and occur mostly due to descent of a posterolaterally enlarging inferior pole of the thyroid gland or very infrequently to failure of fusion of the ultimobranchial bodies with the isthmus in the 7th embryonic week. Intrathoracic location of goiter is less frequent and often can be mistaken as pulmonary lesion, aortic arch aneurysm, and other mediastinal tumors. Patients may be asymptomatic initially but subsequently present with local compressive symptoms. Although most anterior mediastinal goiters are resectable via transcervical approach, PMGs usually require combined approach, cervical, as well as thoracotomy for complete excision.
| Case Report|| |
A 52-year-old female presented with complaints of nonspecific chest pain and difficulty in swallowing solid food for 1-month duration. There was no history of neck mass, breathing difficulty, hoarseness of voice not and no symptoms suggestive of hypo- or hyperthyroidism. General examination of the patient was unremarkable and local examination of the face neck and chest revealed no evidence of neck mass or jugular engorgement, no facial edema or engorged veins, no carotid bruit on auscultation, and normal systemic examination. Chest X-ray anteroposterior and neck X-ray revealed a well-defined radio-opaque homogenous mass lesion on the right side of the trachea extending from CV7 to DV5 vertebral body displacing the trachea to left [Figure 1]. The patient was further evaluated with a contrast-enhanced computed tomography (CT) chest, which showed a large heterogeneous enhancing mass (5.7 cm × 6.0 cm × 8.55 cm) from the posteroinferior aspect of the right lobe of the thyroid and extending caudally into the posterior mediastinum till bifurcation of the trachea, compressing trachea with minimal luminal narrowing and deviation to the left and also compressing esophagus [Figure 2]a and [Figure 2]b. Due to unusual and rare presentation of the thyroid mass in posterior mediastinum and inconclusive X-ray and CT findings, upper gastrointestinal endoscopy (UGIE)-guided fine-needle aspiration cytology (FNAC) of posterior mediastinal mass was done to obtain tissue diagnosis and to differentiate it from other mediastinal tumors. Histopathology revealed thyroid follicles with colloid suggestive of the thyroid tissue. After a multidisciplinary discussion, surgical excision was planned via a combined approach: the right lobe of the thyroid was mobilized caudally through the cervical incision [Figure 3] and a separate sternotomy incision with right lateral extension was made to mobilize mediastinal structures laterally. Intraoperative findings: 13 cm × 6 cm × 4 mm nodular thyroid mass extending from neck to posterior mediastinum, partially compressing the trachea, esophagus, and great vessels [Figure 3]. The final specimen [Figure 4] was resected from the posterior mediastinum without injury to great vessels, recurrent laryngeal nerve (RLN), and phrenic nerve. Intercostal drain (right) was placed and the sternotomy wound was closed. The postoperative period was uneventful and the patient was discharged on the 6th postoperative day. The final histopathological diagnosis was adenomatous goiter with multiple nodules comprised multiple thyroid follicles lined by benign cuboidal cells and a few Hurthle cells separated by thin fibrous septae without any features of malignancy [Figure 5].
|Figure 1: Radiograph shows a well-defined smoothly marginated homogenous radio-opacity in the right upper zone. The lesions show distinct lateral and inferior margins; however, the medial margin is indistinct and merges with the superior mediastinum. The superior margin of the lesions is indistinct and seen extending above the right clavicle (red arrow) merging with soft tissues of neck (cervicothoracic sign positive) - Features suggestive of posterior mediastinal mass from the cervical extension? Thyroid lesion (blue arrow)|
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|Figure 2: (a) The contrast-enhancing CT images (sagittal view) show a well-defined heterogeneously enhancing mass lesion (red arrow) measuring 57 mm × 60 mm × 85 mm, with small patchy nonenhancing areas within is noted involving posterior mediastinum. (b) Axial view, the lesion is extending craniocaudally from the right lobe of the thyroid (red arrow) up to DV4 vertebra. Anteriorly the lesion is abutting SVC (blue arrow) and reaching up to distal aspect of the right CCA. Medially lesion is compressing the bifurcation of trachea (yellow arrow) and insinuating the descending thoracic aorta (green arrow). SVC: Superior vena cava, CT: Computed tomography, CCA: Common carotid artery|
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|Figure 4: Postoperative specimen (note the small cervical component with predominantly mediastinal component)|
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|Figure 5: H and E, ×40 showing numerous thyroid follicles of varying size with micro (red arrow) and macro (blue arrow) follicles. Each follicle is lined by cubical to flattened epithelial and filled with homogenous eosinophilic material colloid (yellow star)|
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| Discussion|| |
PMGs are rare and account for 2% of retrosternal goiters. PMGs are usually characterized by slow progression and a longer course of illness. Patients are usually asymptomatic, to begin with, but subsequently develop pressure symptoms such as dyspnea, cough, choking sensations, stridor, difficulty in swallowing, and facial puffiness due to compression and displacement of the trachea, bronchi, esophagus, or large veins. Patients with retrosternal goiter usually have a visible or palpable cervical mass on presentation and depending on the extension and involvement of other organs retrosternal goiters can lead to hoarseness, anhelation, wheezing, superior vena cava compression, and Horner's syndrome. Our patient had atypical chest pain and progressive dysphagia to solids but no neck mass clinically. Imaging (X-ray/CT scan) and guided FNAC help in differentiating PMG from other mediastinal masses such as aortic or innominate artery aneurysm, thymoma, dermoid cyst, fibroma, neurogenic tumor, and lymphoma. Surgical excision is the treatment of choice and contrary to the most anterior mediastinal goiters which can be removed by a transcervical approach, PMGs which extend beyond the bifurcation of the trachea requires sternotomy in addition to cervical incision. Intraoperative and postoperative complications include pneumonia, atelectasis, pleural effusion, great vessel injury, hypocalcaemia, RLN palsy, and phrenic nerve injury and can result in protracted recovery.
| Conclusion|| |
PMG is a rare entity with varied presentation and at times needs to be differentiated from other posterior mediastinal masses. CT is considered the most valuable modality in detecting PMG. However, in our case, since the CT scan was nonconfirmatory, we did a UGIE guide biopsy from the posterior mediastinal lesion for confirmation of diagnosis. Sonography and radioisotope scan were not considered because of their low diagnostic value and PMG was resected via a combined approach: The cervical part through Kocher's incision and posterior mediastinal part through limited median sternotomy with right extension [Figure 4]. Since both incisions were separate, it helped in good healing without any skin necrosis. The patient did well postoperatively without any complications.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given his consent for images and other clinical information to be reported in the journal. The guardian understands that names and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]