Diagnosis of multinodular goiter by endoscopic ultrasound-guided fine-needle aspiration

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been used to diagnose a variety of mediastinal masses, including lymphoma, neurogenic tumors, sarcoidosis, and malignant metastasis [1]. We report here a patient with a large superior mediastinal mass that was diagnosed as multinodular goiter by means of EUS-FNA.

A 67-year-old woman was admitted for resection of a colon cancer. A preoperative chest radiograph showed a right paratracheal mass (Figure [1]), and computed tomography of the chest revealed a large multinodular goiter that extended into the mediastinum and a mediastinal mass extending retrosternally and contiguous with a large retrotracheal mass (Figure [2]). Metastatic lymphadenopathy or a primary esophageal mass were considered in the differential diagnosis of this lesion in a patient with known colon cancer. Endoscopic ultrasound with a linear echo endoscope demonstrated a heterogeneous mass in the superior mediastinum, 5 cm × 6 cm in size, with several anechoic areas, located 20 cm from the incisor teeth. EUS-FNA was performed using a 22-gauge needle, and two needle passes were made (Figure [3]).

Figure 1 The preoperative chest radiograph in a patient with known colon carcinoma showed a large right paratracheal mass.

Figure 2 a Contrast-enhanced computed tomography of the chest revealed an enlarged, heterogeneous thyroid that extended into the mediastinum. b The inferior portion of the mass was significantly enlarged and appeared removed from the thyroid.

Figure 3 Endoscopic ultrasound view showing a heterogeneous mass measuring 5 cm × 6 cm in the superior mediastinum with several anechoic areas, an appearance suggestive of cystic degeneration.

On-site cytopathological examination revealed cyst material, colloid with macrophages, and rare groups of benign follicular cells, findings consistent with cystic degeneration in a multinodular goiter (Figure [4] ). Because the patient was asymptomatic with respect to the mediastinal mass and because no malignancy was identified by EUS-FNA, the goiter was not investigated further and she underwent successful colectomy. At 12-month follow-up she remained asymptomatic and repeat computed tomography showed that there had been no change in the size of the goiter.

Figure 4 a Cytopathological examination showed follicular cells, consistent with a thyroid mass. b This appearance of a single pigment-laden macrophage on a background of colloid was consistent with a diagnosis of cystic degeneration in a multinodular goiter.

To our knowledge, there has only been one case of EUS-FNA of a thyroid mass reported in the literature [2]. In that report, a benign nodular goiter was diagnosed by EUS-FNA of a calcified superior mediastinal mass. In our patient, several anechoic areas were seen within the mediastinal mass at endoscopic ultrasound that were consistent with cystic degeneration. Fine-needle aspiration confirmed the diagnosis of goiter and excluded the presence of malignancy. Because EUS-FNA can be performed under conscious sedation, it is an attractive alternative to surgical or percutaneous sampling of accessible superior mediastinal lesions. In addition, EUS-FNA can be performed under direct, real-time ultrasound visualization. However, it is important to arrange follow-up of these patients because a small tumor within the goiter could be missed by EUS-FNA.

Endoscopy_UCTN_Code_CPL_1AL_2AC

References

• 1 Panelli F, Erickson R A, Prasad V M. Evaluation of mediastinal masses by endoscopic ultrasound and endoscopic ultrasound-guided fine-needle aspiration.  Am J Gastroenterol. 2001;  96 401-408
• 2 DeWitt J, Youssef W, LeBlanc J. et al . EUS-guided FNA of a thyroid mass.  Gastrointest Endosc. 2004;  59 307-310