Papillary Thyroid Carcinoma Spreading into Branchial Cleft Cyst

Papillary thyroid carcinoma in a branchial cleft cyst

Summary

Papillary thyroid carcinoma (PTC) in a branchial cleft cyst (BCC) is exceedingly rare. This case report describes a 53-year-old male with a BCC containing PTC. Despite normal preoperative thyroid imaging, total thyroidectomy revealed multifocal bilateral micropapillary thyroid carcinoma with a contralateral metastatic lymph node, suggesting an aggressive disease course. This finding supports the likelihood that thyroid gland carcinoma metastasized to the BCC. However, the possibility of a primary tumor arising from ectopic thyroid tissue within the cyst cannot be excluded. To our knowledge, this is the 11th reported case of papillary thyroid cancer noted in a BCC. The patient underwent successful treatment, including radioiodine ablation, highlighting the importance of thorough diagnostic evaluation and management in such rare presentations.

Learning points

While most BCCs are benign, PTC can very rarely present within BCC. Metastatic PTC with a necrotic lymph node is often misdiagnosed as BCC, both radiographically and histologically. Since PTC arising as a primary tumor from ectopic thyroid tissue within a BCC is extremely rare, total thyroidectomy should be considered even in patients with radiographically normal thyroid to rule out micropapillary primary thyroid tumors. A thyroglobulin assay from the needle washout of a fine-needle aspiration of a BCC may help preoperatively identify differentiated thyroid cancers. Micropapillary thyroid cancers (<1 cm) are usually indolent, but some may show nodal metastases and clinical progression.

Papillary Thyroid Carcinoma within a Second Branchial Cleft Cyst. A Diagnostic and Treatment Challenge

INTRODUCTION

Lateral cervical cystic masses are a relatively common occurrence in the otolaryngology practice, which are often attributed to second branchial cleft cysts. However, there should always be a high suspicion for malignancy until proven otherwise.

CASE PRESENTATION

We present a clinical report of a lateral cervical cyst surgical excision where histopathological examination has revealed features of a branchial cleft cyst harboring a papillary thyroid carcinoma. This led to the clinically latent thyroid primary which was treated through thyroidectomy with selective neck dissection and radioactive iodine therapy.

DISCUSSION

Across current literature regarding thyroid carcinomas arising within branchial cysts, primary thyroid carcinoma was identified in almost half the cases where thyroidectomy was performed. There is no established consensus on the decision of whether to perform a thyroidectomy in such cases, due to the paucity of data for similar cases.

CONCLUSION

Although branchial cyst is a benign condition, it can harbor malignancy. When thyroid carcinoma occurs within such a cyst, without solid evidence of a thyroid primary, treating physicians are presented with a diagnostic and treatment dilemma. As more cases are discovered and reported, navigating this challenging dilemma will become clearer for the treating physicians.

Metastatic Papillary Thyroid Microcarcinoma Presenting as a Branchial Cleft Cyst in Young Female

Though aetiology of lateral neck masses is complex, branchial cleft cyst is the second most common congenital lesions of the neck next only to thyroglossal duct cysts. Rarely ectopic thyroid tissue within a branchial cleft cyst may develop into primary papillary carcinoma, and even more rarely it may harbour metastases of primary thyroid papillary carcinoma. We report a rare case of lateral cystic neck mass in a 24-year-old female patient diagnosed as metastatic PTC. The patient was diagnosed after she underwent surgical excision of branchial cleft cyst. Later prospectively the patient underwent total thyroidectomy which revealed papillary thyroid micro invasive carcinoma.

Unusual coexistence: branchial cleft cyst harboring papillary thyroid carcinoma with lymph node metastasis - a rare case report and clinical insights

Background

The simultaneous occurrence of Branchial Cleft Cyst (BCC) and Papillary Thyroid Carcinoma (PTC) represents an unusual malignant tumor, with cases featuring associated lymph node metastasis being particularly rare. This combination underscores an increased potential for metastasis, and the assessment of neck masses, particularly on the lateral aspect, may inadvertently overlook the scrutiny of the thyroid. Therefore, healthcare providers should exercise vigilance, especially in patients over the age of 40, regarding the potential for neck masses to signify metastasis from thyroid malignancies. Currently, surgical intervention stands as the primary effective curative method, while the postoperative administration of radioactive iodine therapy remains a topic of ongoing debate.

Case report

In the presented case, a 48-year-old male patient with a right neck mass underwent surgical intervention. The procedure included the excision of the right neck mass, unilateral thyroidectomy with isthmus resection, and functional neck lymph node dissection under tracheal intubation and general anesthesia. Postoperative pathology findings revealed the coexistence of a BCC with metastatic PTC in the right neck mass, as well as papillary carcinoma in the right thyroid lobe. Lymph node metastasis was observed in the central and levels III of the right neck.

Conclusion

The rare amalgamation of a BCC with PTC and concurrent lymph node metastasis underscores the invasive nature of this malignancy. Healthcare professionals should be well-acquainted with its clinical presentation, pathological characteristics, and diagnostic criteria. A multidisciplinary approach is strongly recommended to enhance patient outcomes.

Branchial Cleft Cyst Harbors Metastatic Papillary Thyroid Carcinoma

Branchial cleft cysts are congenital anomalies which develop in utero, most commonly arising from the second branchial cleft. They are often asymptomatic lateral neck masses but can enlarge and become symptomatic in the setting of infection. The cystic cavity can form a potential space which can harbor infection and, in rare cases, malignant spread of primary tumors. Herein, we present a rare case of a 28-year-old male with an enlarging branchial cleft cyst of six months duration following an upper respiratory infection. Routine post-surgical histopathological examination of the excised mass revealed metastatic papillary thyroid carcinoma. To our knowledge, this case is one of five cases reported within the primary literature. This case draws attention to the occult nature of papillary thyroid carcinoma and the importance of routine histopathological examination of seemingly benign surgically excised lesions.

Papillary thyroid carcinoma metastasis to a branchial cleft cyst: a case report and review of imaging

Branchial cleft cysts are the most common lesions in the lateral neck with ectopic thyroid tissue found only rarely within these cysts. Over the years, multiple cases of papillary thyroid carcinoma arising from these ectopic thyroid tissues have been described in the literature with these cases sharing a normal thyroid gland on surgical and histological evaluation. Recently, however, there are three cases of papillary thyroid carcinoma in a branchial cleft cyst reported to be the result of metastasis from a thyroid primary. We present a 49-year-old female with a rare case of papillary thyroid carcinoma metastasis to a branchial cleft cyst with imaging characteristics that may prospectively suggest metastatic involvement.