Synchronous squamous cell carcinoma and papillary thyroid carcinoma arising from the thyroglossal duct remnant: Case report and a review of the literature

Abstract

Squamous cell carcinoma and papillary thyroid carcinoma simultaneously spreading from the thyroglossal duct remnant (TGDR) is a very rare event. The recognition of this condition allows a correct management and treatment, offering the best chances of cure to the patient. We describe the case of a 42-year-old woman who noticed a right-sided lump in her neck. An ultrasound scan confirmed multiple clusters of enlarged lymph nodes on the right side associated to a pre-hyoidal solid nodule. The thyroid gland was normal. Fine-needle aspiration cytology on two nodes revealed distinct metastases from squamous cell carcinoma and from papillary thyroid carcinoma. A careful screening for other head and neck tumors was negative. She underwent a Sistrunk procedure, total thyroidectomy and right lateral lymphadenectomy with en bloc jugular vein resection. On histology, a 2 cm papillary and a small squamous cell carcinoma of the TGDR were documented, with nodal metastases from both primaries. We report the overall management strategy, treatment and outcome at 26-month follow-up, and a review of the literature.

Synchronous carcinoma of thyroglossal duct cyst and native thyroid gland

“…Similarly, some of the other warning signs such as, dysphonia, stridor or dysphagia, that generally imply malignancy in thyroid nodule could be seen even in non-malignant TDC with unusual location and extension, rendering them non-reliable for predicting malignancy in TDC 22–25. Of all the signs and symptoms, the presence of a suspicious cervical lymph node is probably the most reliable clinical finding to suggest a possible malignant pathology inside the TDC, but the incidence of metastatic cervical lymphadenopathy in TDCC is only around 10%–15% 6 8 11…”

“…Further, similar to the thyroid follicles of a native thyroid gland, these aberrant thyroid follicles of TDC could also undergo a carcinomatous transformation, constituting a peculiar clinical entity called the thyroglossal duct cyst carcinoma (TDCC) 5. Histologically, the majority of the TDCCs tend to be papillary cancers, but rarely could there be a focus of follicular carcinoma, squamous cell carcinoma or even mucoepidermoid carcinoma inside the TDC 6–8. There are also reports of TDCC being coexistent with the concurrent carcinoma of the native thyroid gland 9–12…”

Evidence and controversies in management of thyroglossal duct cyst carcinoma

“…These neoplasms tend to behave more aggressively than their PTC or follicular counterparts and usually present a more dismal prognosis. Very seldom, SCC and thyroid-like tumours may be synchronously present within the same TGDC, with only four cases reported in the literature to date [10][11][12][13].…”

In the Basis of Hashimoto’s Thyroiditis, to Form Papillary Thyroid Carcinoma, Metastasized and Then to De-Differentiate into Poorly Differentiated Squamous Cell Carcinoma

“…In theory, the thyroid gland has no squamous epithelium, and how primary squamous cell carcinoma of the thyroid occurs is still a controversial issue. At present, some researchers believe that thyroid SCC may come from embryonic residues [15]. The literature on thyroid SCC is limited to case reports [14] [16] [17] [18] [19] [20].…”