Internal Jugular Vein and Sternocleidomastoid Muscle Invasion by Papillary Carcinoma Thyroid

Abstract

Thyroid cancer has a good prognosis among all cancers, the disease being confined to the thyroid gland for a long time. Thyroid cancer with the direct invasion of internal jugular vein and SCM muscle is a rare condition. In carcinoma thyroid, extensive vascular invasion is considered as a risk factor for distant metastasis and early relapse. We report a case of carcinoma thyroid with internal jugular vein tumor thrombosis and sternocleidomastoid muscle invasion with review of literature.

Introduction

Papillary carcinoma is the most common subtype of thyroid cancer. The usual presentation is asymptomatic swelling in front of the neck. Papillary carcinoma remains confined to the thyroid gland for a long time. Thyroid cancers have the propensity to spread to regional lymph nodes and distant metastasis to lung and bone. Although differentiated cancer may show microscopic vascular invasion, tumor thrombosis into the internal jugular vein is a rare phenomenon [1]. We report a case of carcinoma thyroid with internal jugular vein tumor thrombosis and sternocleidomastoid muscle invasion.

Case Report

A 50-year old male presented with complaints of swelling in front of the neck along with difficulty in swallowing. No symptoms suggestive of hypothyroid/hyperthyroid were present. The patient did not complain of a change in voice or breathing difficulty. Physical examination revealed solitary swelling measuring 8*7 cm arising from the left lobe of thyroid along with left cervical lymphadenopathy. Neck ultrasonography (USG) confirmed a large heterogeneously hypogenic lesion with foci of macrocalcification and internal vascularity arising from the left lobe of the thyroid, there was tumor thrombus in the internal jugular vein. To confirm the finding of ultrasonography a CT (computed tomography) scan was done. CECT (contrast-enhanced computed tomography) revealed a large mass in the left thyroid lobe associated with left internal jugular vein tumor thrombosis along with sternocleidomastoid muscle invasion. The fine needle aspiration cytology of the thyroid nodule revealed papillary carcinoma. Routine blood investigations and thyroid function test was within a normal range. The patient was posted for surgery after detailed counseling and consent.

The operative finding confirmed imaging report there was an enlarged left lobe of thyroid involving internal jugular vein and sternocleidomastoid muscle (Fig. 1). Multiple lymph nodes were found in level II and level III. Total thyroidectomy with en bloc resection of the internal jugular vein and SCM muscle was performed. Also, central and left radical neck dissection was done (Fig. 2). The carotid artery and vagus nerve were saved on the left side (Fig. 2).

Fig. 1.

Intra op photograph showing tumour in left lobe of thyroid invading Internal jugular vein and sternocleidomastoid muscle

Fig. 2.

Intra op photograph, post total thyoidectomy with enbloc excision of Internal jugular vein and sternocleidomastoid muscle. Showing Carotid and vagus nerve

The recurrent laryngeal nerve on both sides and the parathyroid gland on the right side were seen and preserved. The drain was placed and the wound was closed. There was no hoarseness in the postoperative period. But, the patient developed perioral numbness, paresthesias of the hands and feet on 2nd postoperative day. On physical examination chvostek’s sign and trousseau sign were positive (https://www.youtube.com/watch?v=CBWURzvGaZg). The patient was treated with calcium and vitamin-D supplements. With this treatment, hypocalcemia was controlled and he recovered completely from symptoms of hypocalcemia. On the 4th postoperative day, he was discharged on oral calcium and Vitamin D supplements.

Final histopathology revealed papillary carcinoma thyroid with internal jugular vein invasion. 3 out of 17 lymph nodes were positive for metastasis. The patient was planned for adjuvant radioactive iodine treatment.

Discussion

Thyroid cancer with the direct involvement of internal jugular vein and SCM muscle is a very rare condition. Thyroid cancer usually has a good prognosis disease being confined to the thyroid gland for a long time. In a few cases, thyroid cancer tends to metastasize to regional lymph nodes and distantly most commonly to lung and bones. Internal Jugular Vein and sternocleidomastoid muscle invasion by papillary Carcinoma thyroid are very rare. In carcinoma thyroid, extensive vascular invasion or venous tumor thrombosis should be a consideration as a risk factor of distant metastasis or early relapse. The thyroid carcinoma is generally a slow-growing tumor, therefore tumor thrombosis of thyroid cancer in a major vein and with SCM muscle is very rare. The tumor thrombus may be detected along with the thyroid tumor at the initial presentation or with recurrence in the Thyroid bed or nodes. Often the thrombus is not clinically detected by examinations alone. Ultrasound neck is the first investigation to be done when we are suspecting vein invasion [2]. CT with IV contrast is the gold standard for confirming vein invasion and see the local extent of disease in the neck [3]. In addition to imaging FNAC need to be done to rule out poorly differentiated subtype like anaplastic carcinoma where the prognosis is dismal.

Once the diagnosis of well-differentiated thyroid cancer is made, surgery is the best option to cure the patient [4, 5]. Many times cure is not possible but long term control can be achieved by surgery and adjuvant treatment. The surgery involved total thyroidectomy with resection of involved structures in the neck. Neck dissection must be done in all cases of locally advanced tumors [6].

All patients require postoperative radioiodine treatment to treat microscopic disease [7]. The role of adjuvant radiation is controversial. If R2 resection was done and there is a remnant macroscopic disease in the neck, external beam radiation must be added to prolong survival. The patient must be kept on high dose thyroid hormone replacement after completion of treatment. There is no sufficient long term follow up information available to through light on the prognosis of thyroid carcinoma with great vein thrombosis with SCM muscle invasion. Whatever literature is available demonstrated long survival and cancer control seen in patients who underwent surgery as compared to the patient in whom surgery was deferred.

Conclusion

Thyroid Carcinoma involving the IJV and SCM muscle is a rare phenomenon. Invasion of IJV and SCM is not a sign of inoperability. With extensive surgery involving total thyroidectomy with resection of involved structures followed by radioiodine treatment, leads to prolonged survival and in some patients cure.

Funding

None.

Compliance with Ethical Standards

Conflict of interest

The authors declares that they have no conflicts of interest.