Primary squamous cell carcinoma of thyroid: a case report and review of literature

Progress in diagnosing and treating thyroid squamous cell carcinoma under the 5th edition of WHO classification

Squamous cell carcinoma of the thyroid (SCCT) is a rare thyroid gland malignancy, with only a few hundred cases reported in the literature, mostly as case reports or small sample studies. In the previous WHO classification, squamous cell carcinoma of the thyroid was defined as a carcinoma composed entirely of squamous cells without differentiated carcinoma components. It was once included in the WHO tumor classification separately. However, the 2022 WHO classification of squamous cell carcinoma of the thyroid was reclassified as a morphologic subtype of anaplastic thyroid carcinoma (ATC). The squamous cell carcinoma pattern is similar to the other histologic types of ATC, but the phenotype associated has a poorer prognosis. The typical clinical manifestation of this condition is a cervical mass, accompanied by indications and symptoms of compression on adjacent structures such as the esophagus and trachea in advanced stages. Secondary squamous cell carcinoma of the thyroid may occur due to the spread of squamous carcinoma of the larynx or esophagus or distant metastases from other sites. Diagnosis of squamous cell carcinoma of the thyroid includes neck Ultrasound (US), Computed Tomography (CT) or Magnetic Resonance Imaging (MRI), puncture tissue biopsy, and full endoscopy to identify metastatic lesions from the nasopharynx, oropharynx, hypopharynx, larynx, esophagus, or bronchi and to help with the initial staging of the tumor. Current treatment modalities include surgery, radiotherapy, chemotherapy, or a combination. Because of the poor prognosis of patients with this disease, the short survival period, usually less than one year, and the difficulty of preoperative diagnosis, this article reviews the epidemiological features, origin, clinical features, pathological features, and differential diagnosis to improve the diagnosis and treatment of this disease by clinicians.

Immunotherapy for the Treatment of Squamous Cell Carcinoma: Potential Benefits and Challenges

Melanoma and nonmelanoma skin cancers (NMSCs) are recognized as among the most common neoplasms, mostly in white people, with an increasing incidence rate. Among the NMSCs, squamous cell carcinoma (SCC) is the most prevalent malignancy known to affect people with a fair complexion who are exposed to extreme ultraviolet radiation (UVR), have a hereditary predisposition, or are immunosuppressed. There are several extrinsic and intrinsic determinants that contribute to the pathophysiology of the SCC. The therapeutic modalities depend on the SCC stages, from actinic keratosis to late-stage multiple metastases. Standard treatments include surgical excision, radiotherapy, and chemotherapy. As SCC represents a favorable tumor microenvironment with high tumor mutational burden, infiltration of immune cells, and expression of immune checkpoints, the SCC tumors are highly responsive to immunotherapies. Until now, there are three checkpoint inhibitors, cemiplimab, pembrolizumab, and nivolumab, that are approved for the treatment of advanced, recurrent, or metastatic SCC patients in the United States. Immunotherapy possesses significant therapeutic benefits for patients with metastatic or locally advanced tumors not eligible for surgery or radiotherapy to avoid the potential toxicity caused by the chemotherapies. Despite the high tolerability and efficiency, the existence of some challenges has been revealed such as, resistance to immunotherapy, less availability of the biomarkers, and difficulty in appropriate patient selection. This review aims to accumulate evidence regarding the genetic alterations related to SCC, the factors that contribute to the potential benefits of immunotherapy, and the challenges to follow this treatment regime.

Therapeutic Effect of Combined Dabrafenib and Trametinib Treatment of BRAF V600E-Mutated Primary Squamous Cell Carcinoma of the Thyroid: A Case Report

INTRODUCTION

Primary squamous cell carcinoma (PSCC) of the thyroid is an exceptionally rare malignancy accounting for <1% of all primary thyroid cancers. Therapy is multimodal including surgery, radiotherapy, and chemotherapy but with no consensus for management and therapy. Here, we describe a case of a male patient who presented with a BRAF V600E-mutated PSCC of the thyroid gland showing response to combined dabrafenib and trametinib therapy over a period of >12 months.

CASE PRESENTATION

A 78-year-old male patient presented with a 3-week history of dysphonia and dyspnoea. Laryngoscopy revealed a mechanical obstruction by a right-sided, subglottical mass, which on cervical ultrasound was highly suggestive of anaplastic thyroid carcinoma. Additional workup including esophagogastroduodenoscopy showed compression of the oesophagus but no oesophageal infiltration by the tumour. Immunohistochemistry displayed CK19-positive cells indicating epithelial origin of the tumour. CK5/6 and P40 immunohistochemistry confirmed the morphological impression of squamous cell differentiation while staining with thyroid markers TTF-1 and TPO was negative and PAX8 showed a nuclear positive signal. Based on immunohistopathology, presence of TP53 and BRAF V600E mutations, and exclusion of metastatic squamous cell carcinoma of other origin, the diagnosis of a PSCC of the thyroid was established. As an individualized treatment concept, we decided to advocate combined BRAF V600E targeting by the multikinase inhibitors dabrafenib and trametinib. This led to drastic improvement in patient's quality of life without severe side effects over a period of >12 months.

CONCLUSION

In this case, molecular diagnosis allowed a highly individualized treatment concept with combined dabrafenib and trametinib therapy.

A characterization and prognosis prediction model for primary squamous cell carcinoma of the thyroid

Background

Primary squamous cell carcinoma of the thyroid (PSCCTh) is a sporadic malignancy arising from the thyroid gland. The factors that affect treatment and survival in patients with PSCCTh remain unclear. Our study aims to characterize PSCCTh and establish a prognosis prediction model for patients with PSCCTh.

Methods

Clinical data and follow-up information for 277 patients from 1973 to 2016 were collected from the Surveillance, Epidemiology, and End Results Program (SEER) 18-registry database (RRID:SCR_003293). Univariate and multivariate Cox proportional hazards analyses and nomogram modeling of potential prognostic factors were conducted.

Results

Among the collected patient cases, 57% were female and 43% were male. The median survival of all cases was 6 months; by gender, median survival was 5 and 8 months in the female and male groups, respectively. Univariate and multivariate Cox proportional hazards analyses revealed that age, extent of disease (EOD), T stage, N stage, and treatment were independent prognostic indicators for overall survival (OS) and disease-specific survival (DSS) in patients with PSCCTh. In addition, it was confirmed that the established nomogram model had good consistency and discrimination for PSCCTh prognosis as measured by the concordance index (C-index), area under the receiver operating characteristic (ROC) curve (AUC), and calibration curves.

Conclusions

Our study indicates that age, EOD, T stage, N stage, and treatment may correlate with OS and DSS in patients with PSCCTh. Importantly, our nomogram prediction model, constructed using parameters including age, T stage, N stage, and treatment, may assist physicians in evaluating patients' prognoses and providing precise therapy for PSCCTh.

Primary thyroid squamous cell carcinoma: a challenging management problem

Primary thyroid squamous cell carcinoma (SCC) is a rare and highly aggressive cancer. Diagnostic work-up encompasses cervical ultrasonography, tissue biopsy and CT scan. Surgery, radiotherapy and chemotherapy are the available treatment modalities. With a mean survival rate of 7 months reported in the literature, our patient is alive 2 years after successful treatment of her advanced primary thyroid SCC with surgery and radiotherapy.

Title- Genomic landscape of squamous cell carcinoma- Different genetic pathways culminating in a common phenotype

INTRODUCTION

Squamous cell carcinomas (SqCCs) are the most common solid tumors in humans and are found across multiple organ systems. Although, integrated analysis of genetic alterations divulge similarities between SqCCs from various body sites, certain genes appear to be more frequently mutated in a given SqCC. These subtle differences may hold the key to determining the differentiation characteristics and predicting aggressiveness of tumors.

MATERIALS AND METHOD

Fifty-four cases of SqCCs, in which the primary location of the tumor could be ascertained by clinical and radiological findings, were included in this study. Next generation sequencing data was analyzed for recurrent genetic abnormalities.

RESULTS

Genetic alterations were found in 219 genes in the 54 cases studied. TP53 mutations were found to be more frequent in pulmonary SqCCs (86.5%) as compared to non-pulmonary SqCCs (58.8%) (p<0.05). NOTCH gene family mutations and CREBBP mutations were limited to non-pulmonary SqCC (p<0.005) and were mutated in 41.2% and 17.6% cases.

CONCLUSION

A detailed comparative analysis of the genetic alterations identified by sequencing identified higher frequency of TP53 mutations in lung SqCCs as compared to non-pulmonary SqCCs. NOTCH and CREBPP mutations were found to be absent in lung and head and neck SqCCs and more frequent in SqCCs from other locations.

Primary squamous cell carcinoma of thyroid with a novel BRAF mutation and High PDL-1 expression: A case report with treatment implications and review of literature

Primary squamous cell carcinoma of thyroid (SCC-T) is an extremely rare, aggressive neoplasm with median survival of 9 months. Pure squamous morphology with absence of other cell types is required for diagnosis of SCC-T. Clinically, SCC-T behaves like anaplastic thyroid carcinoma (ATC) showing rapid growth, and extra thyroidal extension. We report a 91-year-old woman presenting with an enlarging thyroid mass and accompanying dysphagia and hoarseness. Fine needle aspiration revealed hypercellular specimen with large, pleomorphic, malignant cells. Intraoperative assessment revealed an inoperable tumor involving both thyroid lobes and extensively infiltrating surrounding soft tissues. A subtotal thyroidectomy was performed. Histology revealed squamous cell carcinoma replacing native thyroid tissue and infiltrating adjacent skeletal muscle. Lymphovascular and perineural invasion were present. Immunohistochemistry showed tumor cells positive for CK5-p40, Pax-8, TTF-1 and negative for thyroglobulin. P53 expression by IHC was high and Ki-67 proliferation index was > 90 %. (Next generation sequencing revealed a novel BRAF mutation (BRAF c.1799 T > A; 1801_1812del) along with TP53 and TERT mutations. PDL-1 immunohistochemistry showed positive expression in tumor cells (>80%), making patient also amenable to anti-PDL-1 immunotherapy. Patient was treated with BRAF inhibitor therapy with initial relief but eventually was put on hospice care due to increasing intolerance to therapy. This case represents a rare thyroid malignancy with a unique molecular signature consisting of a novel BRAF mutation [previously not described in SCC-T or ATC], associated with TERT-TP53 mutations. Further, importance of PDL-1 testing as a prognostic marker and as a guide to immunotherapy in refractory tumors is discussed.

Squamous cell carcinoma of the thyroid gland in an elderly female presenting as a rapidly enlarging thyroid mass

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Squamous cell carcinoma of the thyroid gland is an extremely rare tumor.

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It may be primary tumor within the thyroid gland or as a component of anaplastic or undifferentiated tumors.

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The tumor has a very aggressive clinical behavior with a median survival of few months.

Background

Squamous cell carcinoma of the thyroid gland is an extremely rare tumor with a very aggressive clinical behavior and poor prognosis. The tumor may arise as a primary tumor within the thyroid gland or as a component of anaplastic or undifferentiated thyroid tumors.

Case presentation

A 70-year-old lady with history of long standing multinodular goiter presented with progressive enlargement of a midline nodule for 3 months which was associated with dyspnea and dry cough. The mass was hard and fixed. The voice was normal, other parts of the general examination were unremarkable. Fine needle aspiration was done for the mass which revealed malignant cells mixed with inflammatory cells. During surgery there was a hard and fixed mass arising from the isthmus of the thyroid gland that was locally invading, complete excision was not possible, debulking was done. Histopathology showed moderately differentiated squamous cell carcinoma of the thyroid gland. The tumor underwent local progression 6 months later and the patient was sent for radiotherapy.

Conclusion

When thyroid tumor is advanced at time of diagnosis, radiotherapy is the main form of treatment which may induce reduction in the size of the tumor and decrease pain, radiotherapy may also be given on neoadjuvant bases which may render resection possible in some patients. The tumor is usually not responsive to chemotherapy. The overall survival is uniformly poor regardless of the primary form of treatment, the median survival of the patients from the time of diagnosis is few months in most cases.

Unraveling cancer lineage drivers in squamous cell carcinomas

Cancer hijacks embryonic development and adult wound repair mechanisms to fuel malignancy. Cancer frequently originates from de-regulated adult stem cells or progenitors, which are otherwise essential units for postnatal tissue remodeling and repair. Cancer genomics studies have revealed convergence of multiple cancers across organ sites, including squamous cell carcinomas (SCCs), a common group of cancers arising from the head and neck, esophagus, lung, cervix and skin. In this review, we summarize our current knowledge on the molecular drivers of SCCs, including these five major organ sites. We especially focus our discussion on lineage dependent driver genes and pathways, in the context of squamous development and stratification. We then use skin as a model to discuss the notion of field cancerization during SCC carcinogenesis, and cancer as a wound that never heals. Finally, we turn to the idea of context dependency widely observed in cancer driver genes, and outline literature support and possible explanations for their lineage specific functions. Through these discussions, we aim to provide an up-to-date summary of molecular mechanisms driving tumor plasticity in squamous cancers. Such basic knowledge will be helpful to inform the clinics for better stratifying cancer patients, revealing novel drug targets and providing effective treatment options.

A Case Rarity: Papillary Thyroid Carcinoma with Squamous Metaplasia Complicated with Chronic Discharging Ulcers

We report a unique case of differentiated thyroid carcinoma (DTC) with squamous metaplasia complicated with chronic discharging ulcer. A 76-year-old gentleman was referred to us after defaulted treatment 1 year post-total thyroidectomy. He presented to us with long-standing chronic, non-healing, ulcerative and discharging wound at the anterior neck at previous total thyroidectomy scar. The primary tumour was histologically diagnosed as papillary malignant cells with extensive squamous metaplasia. Squamous metaplasia is a rare finding in thyroid carcinoma that carried a poorer prognostic factor.

Deciphering the cells of origin of squamous cell carcinomas

Squamous cell carcinomas (SCCs) are among the most prevalent human cancers. SCC comprises a wide range of tumours originated from diverse anatomical locations that share common genetic mutations and expression of squamous differentiation markers. SCCs arise from squamous and non-squamous epithelial tissues. Here, we discuss the different studies in which the cell of origin of SCCs has been uncovered by expressing oncogenes and/or deleting tumour suppressor genes in the different cell lineages that compose these epithelia. We present evidence showing that the squamous differentiation phenotype of the tumour depends on the type of mutated oncogene and the cell of origin, which dictate the competence of the cells to initiate SCC formation, as well as on the aggressiveness and invasive properties of these tumours.

Primary squamous cell carcinoma of the thyroid: Case report and systematic review of the literature

BACKGROUND

Primary squamous cell cancer (PSCC) of thyroid is a rare malignancy with poor prognosis. It is mandatory to exclude secondary involvement of the thyroid by panendoscopy, CT-scan and immunohistochemical analysis. As treatment surgery, radiation and rarely chemotherapy is employed.

METHODS

A systematic review of the literature was conducted searching medline and embase database using the medical subject headings "primary squamous cell carcinoma of thyroid" and "primary squamous cell cancer of thyroid", for articles published until April 2016 (n=1733). Of interest were the used treatment modalities and survival outcomes.

RESULTS

A total of 35 publications reporting on 50 cases including ours were finally analyzed. A curative treatment approach was described in 24 patients (48%). Additional radiotherapy, chemotherapy or radiochemotherapy was applied in 17, 7 and 7 patients respectively. Median overall survival was 6 months [range 0-48] for 47 patients. Disease free survival was only achieved in 8 patients with disease limited to the thyroid gland, complete surgical resection and additional radiotherapy or radiochemotherapy [reported median 20 months; range 12-48].

CONCLUSION

Reported disease free survival of PSCC of the thyroid was only achieved in patients with complete surgical resection in combination with adjuvant radio- and/or chemotherapy. However long term survival has not been reported in the literature yet.

Primary squamous cell carcinoma of the thyroid with complete response to radical radiotherapy and concurrent cisplatin-based chemotherapy

Chemoradiotherapy and/or surgery are both potentially radical treatments for squamous cell carcinomas. Squamous cell carcinomas are considered chemosensitive tumours compared to adenocarcinomas or anaplastic thyroid malignancies. A 76-year-old man was found to have T4bN0M0 primary squamous cell carcinoma of the thyroid with encasement of the internal carotid artery. The disease was deemed unresectable. Therefore, he was treated with radical radiotherapy with concurrent cisplatin-based chemotherapy. We discuss herein the aetiology, diagnosis and management of primary squamous cell carcinoma of the thyroid. We demonstrate success of chemoradiotherapy in an unresectable case of a rare and aggressive disease.

Squamous Cell Cancers: A Unified Perspective on Biology and Genetics

Squamous cell carcinomas (SCCs) represent the most frequent human solid tumors and are a major cause of cancer mortality. These highly heterogeneous tumors arise from closely interconnected epithelial cell populations with intrinsic self-renewal potential inversely related to the stratified differentiation program. SCCs can also originate from simple or pseudo-stratified epithelia through activation of quiescent cells and/or a switch in cell-fate determination. Here, we focus on specific determinants implicated in the development of SCCs by recent large-scale genomic, genetic, and epigenetic studies, and complementary functional analysis. The evidence indicates that SCCs from various body sites, while clinically treated as separate entities, have common determinants, pointing to a unified perspective of the disease and potential new avenues for prevention and treatment.

Less aggressive disease in patients with primary squamous cell carcinomas of the thyroid gland and coexisting lymphocytic thyroiditis

Aim of the study

Primary squamous cell carcinoma (SCC) of the thyroid gland is extremely rare. Infrequently, primary SCC of the thyroid gland is accompanied by other thyroid diseases such as Hashimoto's thyroiditis (HT). Recently, studies have demonstrated that differentiated thyroid cancer with coexisting HT has a better prognosis. However, the prognosis of patients with primary SCC of the thyroid gland and coexistent HT has not been clearly identified. We compared the clinical characteristics and disease stages of patients with primary SCC with and without lymphocytic thyroiditis (LT).

Material and methods

We reviewed reports of primary SCC of the thyroid gland published in the English literature.

Results and conclusions

We identified 46 papers that included 17 cases of primary SCC of the thyroid gland with LT and 77 cases of primary SCC of the thyroid gland without LT. Lymph node metastasis and local invasion rates did not differ between these two groups. Distant metastases were absent in patients with LT, and were observed in 13 (16.9%) patients without LT. A greater proportion of patients without LT had advanced stage disease (stage IV A-B-C) than patients with LT (p < 0.05). Patients with primary SCC of the thyroid gland and coexisting LT had lower tumour-node-metastasis stage and frequency of distant metastasis than those without LT. Lymphocytic infiltration in patients with SCC appears to limit tumour growth and distant metastases.

Primary squamous cell carcinoma of the thyroid gland

Primary squamous cell carcinoma (SCC) of the thyroid gland is a very rare entity representing <1% of all primary carcinomas of the thyroid gland with a very poor prognosis. We report a rare case of a 65-year-old woman with SCC of the thyroid gland, emphasizing the postoperative complications and poor prognosis of these patients. Surgical excision of primary SCC of the thyroid gland when possible is the optimal therapy. Chemo- and radiotherapy rarely have place in its treatment as this malignancy has a poor response to chemotherapy and in many cases is radio-resistant. Median survival of these patients is around 6 months.

Primary squamous cell carcinomas in the thyroid gland: an individual participant data meta-analysis

Primary squamous cell carcinomas arising from the thyroid gland (SCCTh) is extremely rare diseases, which have never been fully studied. Thus, we performed a systematic review and individual participant data meta-analysis of published SCCTh cases, to understand the clinical characteristics and to identify the prognostic factors of primary SCCTh. A literature search was conducted within Medline, EMBASE, Cochrane library databases and KoreaMed using the following Medical Subject Headings (MeSH) keywords: “primary,” “squamous,” “carcinoma,” “cancer,” and “thyroid.” Eighty-four patients' individual data from 39 articles and five patients' data in our institute were selected for analysis (N = 89). The mean age at diagnosis was 63.0 years (range, 24–90) and female preponderance (M:F = 1:2) was noted. The commonest complaint was the anterior neck mass, followed by dyspnea or dysphagia, and extension to the adjacent structure was found in 72%. The median survival was 9.0 months (95% CI, 6.0–23.0) and 3-year survival rate (3YSR) was 37.6% by Kaplan–Meier method, but only 20.1% by a shared frailty model for adjusting heterogeneity. Complete resection (R0) of tumors was the only significant prognostic factor in multivariable analysis, and the benefit of adjuvant treatment was not proved. The prognosis of patients with SCCTh is very poor (20% in 3YSR), but complete resection of disease is correlated with improved survival. To achieve complete surgical eradication of tumors, early detection and accurate diagnosis should be emphasized.

Primary squamous cell of the thyroid-an abbreviated clinical presentation

BACKGROUND

Lacking any squamous epithelium, thyroid gland with primary squamous cell carcinoma (PSCC) proves to be an etiopathophysiological quandary. Two major theories do exist, though few cases have been documented to support either. We present a case that supports the "metaplasia" theory, which serves to enhance our understanding of a disease that carries with it a very poor prognosis.

CASE PRESENTATION

We present a case of an extremely advanced, primary squamous cell carcinoma of the thyroid with distant metastases in a thirty-six year-old male. Dying of airway compromise seventeen days following his admission, this is the shortest median survival of all documented cases.

CONCLUSION

In addition to being the most abbreviated time period between presentation and death of all documented thyroid primary squamous cell carcinomas, we share the fifth case of thyroid PSCC in the setting of lymphocytic thyroiditis. This case should build awareness of the aggressivity of the disease and the lack of established diagnostic criteria.

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

Primary squamous cell carcinoma of the thyroid gland (PSCCT) is a rare malignancy that presents with advanced disease and poor prognosis. It is difficult to diagnose PSCCT in its early stage because of its rarity and lack of typical imaging findings. We experienced an elderly woman with PSCCT confirmed by surgery. Although preoperative fine-needle aspiration revealed no malignancy, surgical resection was performed because the ultrasonogram showed diffuse microcalcifications, which suggested malignancy, and clinically, the mass grew rapidly to compress the trachea. Local tumor recurrence was noted at 3 months after surgery. Surgical resection or repeat biopsy should be considered if a cytologically benign thyroid mass shows imaging or clinical features of malignancy.