Primary squamous cell carcinoma of the thyroid gland: A case report and review

Abstract

The case and literature reported here support that a thorough diagnostic workup of primary SCC of the thyroid with aggressive locoregional surgery and adjuvant RT may improve the length of survival.

Primary squamous cell carcinoma of thyroid gland with local recurrence: ultrasonographic and computed tomographic findings

“…Regarding CT findings, there have been only a few case reports, and most of them have shown a huge mass containing focal cystic changes or coarse and curvilinear calcification, resulting in airway compression [6,7,10,11]. In our case, the neck CT showed a huge, heterogeneously enhancing thyroid mass with large central nonenhancing portion compressing the trachea, similar to previous reports.…”

“…Although several reported cases of PSCCT have been diagnosed by FNA [5,6], the cytological findings are typically nonspecific, and clinical correlation is needed for correct diagnosis [4,7]. In our case, the repetitive cytological results suggested a benign pathology, but postoperative histopathologic examination revealed malignancy.…”

Primary squamous cell carcinoma of the thyroid: a rare type of thyroid cancer

“…The embryonic rest cell theory depends on squamous cell derivation from remnants of the thyroglossal duct and thymic epithelium [5,6]. According to the second "metaplasia" theory, the source of squamous cells is from follicular, papillary or anaplastic cells [7]. In our patient, Hashimoto's Thyroiditis was not observed in surgical specimen.…”

Primary Squamous Cell Carcinoma of the Thyroid Diagnosed as Anaplastic Carcinoma: Failure in Fine-Needle Aspiration Cytology?

“…Clinically, primary SCCs of the thyroid and ATC are similar because they are both very aggressive [12]. Indeed, differentiation between these two types of lesions is often difficult, particularly when attempting diagnosis from fine-needle aspiration cytology, and additional differential diagnosis includes ATC with focal SCC component or squamous metaplasia [13] and the intrathyroid epithelial thymoma (ITET)/carcinoma showing thymus-like differentiation (CASTLE) [14]. ITET/CASTLE has less aggressive biological characteristics than primary thyroid SCC and the main features for the differential diagnosis are the positive immunoreactivity for CD5 and a proliferation index usually smaller than 20% [14].…”

“…In addition, there was intense chronic inflammation that resulted in thickened walls of blood vessels. Though being rare, the association between primary SCC of the thyroid and chronic thyroiditis has been found, and there are few reported cases [9, 13, 17–19]. In this context, SCC cells would originate from squamous metaplasia of follicular cells, which is promoted by chronic inflammation [7, 16].…”