Primary Squamous Cell Carcinoma of the Thyroid: A Population-Based Analysis

To diagnose primary and secondary squamous cell carcinoma of the thyroid with ultrasound malignancy risk stratification

Objectives

This study aimed to investigate the clinico-ultrasound features of primary squamous cell carcinoma of the thyroid (PSCCT) and secondary SCCT (SSCCT) and evaluate the accuracy of fine needle aspiration (FNA) recommendation for SCCT with American College of Radiology-Thyroid Imaging and Reporting Data System (ACR-TIRADS) and Chinese-TIRADS (C-TIRADS).

Materials and methods

We retrieved 26 SCCT patients (11 PSCCT, 15 SSCCT) from our hospital's pathology database (5,718 patients with thyroid malignancy) over 23 years. Medical records and ultrasound data of the 26 patients with 27 SCCTs were analyzed retrospectively, and each SCCT focus was categorized based on the two TIRADSs.

Results

For 26 patients (21 males, 5 females) with an age range of 42-81 years, rapidly enlarging thyroid/neck nodules (18/26, 69.2%), dysphagia (7/26, 26.9%), hoarseness (6/26, 23.1%), dyspnea (5/26, 19.6%), cough (4/26, 15.4%), neck pain (2/26, 7.7%), B symptoms (2/26, 7.7%), and blood in sputum (1/26, 3.8%) were presented at diagnosis. Five asymptomatic patients (5/26, 19.2%) were detected by ultrasound. Hoarseness was more common in PSCCT (5/11, 45.5%) than in SSCCT (1/15, 6.7%) (P=0.032). For 27 SCCTs with a mean size of 3.7 ± 1.3 cm, the ultrasound features consisted of solid (25/27, 92.6%) or almost completely solid composition (2/27, 7.4%), hypoechoic (17/27, 63%) and very hypoechoic echogenicity (10/27, 37%), irregular/lobulated margin with extra-thyroidal extension (27/27, 100%), taller-than-wide shape (13/27, 48.1%), punctate echogenic foci (6/27, 22.2%), hypervascularity (23/27, 85.2%) and involved neck lymph (13/26, 50.0%). A total of 27 SCCTs were evaluated as high malignancy risk stratification (≥TR4 and 4B) by the two TIRADSs and recommended FNA in 96.3-100% (26/27, 27/27). Pathologically, more than half of PSCCTs (7/12, 58.3%) and a quarter of SSCCTs (4/15, 26.7%) were poorly differentiated, while moderately and well-differentiated grades were observed in 5 PSCCTs and 11 SSCCTs (P=0.007). Thirteen patients (50.0%) underwent surgery with radical operation in 5 cases (5/13, 38.5%).

Conclusion

SCCT is an extremely rare and aggressive malignancy with a male predominance. PSCCT and SSCCT had similar clinical and ultrasound features except for tumor differentiation and the symptom of hoarseness. SCCT showed a high malignancy risk stratification in ACR-TIRADS and C-TIRADS, with a high rate of FNA recommendation.

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.

A Competing Risk Nomogram for Prediction of Prognosis in Patients With Primary Squamous Cell Thyroid Carcinoma

Objective: Primary squamous cell thyroid carcinoma (PSCTC) is an extremely rare carcinoma, accounting for less than 1% of all thyroid carcinomas. However, the factors contributing to PSCTC outcomes remain unclear. This study aimed to identify the prognostic factors and develop a prognostic predictive model for patients with PSCTC. Methods: The analysis included patients diagnosed with thyroid carcinoma between 1975 and 2016 from the Surveillance, Epidemiology, and End Results database. Prognostic differences among the 5 pathological types of thyroid carcinomas were analyzed. To determine prognostic factors in PSCTC patients, the Cox regression model and Fine-Gray competing risk model were utilized. Based on the Fine-Gray competing risk model, a nomogram was established for predicting the prognosis of patients with PSCTC. Results: A total of 198,757 thyroid carcinoma patients, including 218 PSCTC patients, were identified. We found that PSCTC and anaplastic thyroid cancer had the worst prognosis among the 5 pathological types of thyroid carcinoma (P < .001). According to univariate and multivariate Cox regression analyses, age (71-95 years) was an independent risk factor for poorer overall survival and disease-specific survival in PSCTC patients. Using Fine-Gray regression analysis, the total number of in situ/malignant tumors for patient (Number 1) (≥2) was identified as an independent protective factor for prognosis of PSCTC. The area under the curve, the concordance index (C-index), calibration curves and decision curve analysis revealed that the nomogram was capable of predicting the prognosis of PSCTC patients accurately. Conclusion: The competing risk nomogram is highly accurate in predicting prognosis for patients with PSCTC, which may help clinicians to optimize individualized treatment decisions.

Primary squamous cell carcinoma of thyroid gland-First case report from state Punjab, India

Primary squamous cell carcinoma of the thyroid is a very rare thyroid malignancy. In addition, due to its presentation as a locally advanced disease with a high tendency to metastasize, it has a poor prognosis and outcome. We report a 60-year-old male patient with PSCC, which was confirmed by immunohistochemistry on biopsy. The patient was staged as T4N1M0 and was planned as per the multidisciplinary team approach. In sum, pathologic examination and IHC aid in distinguishing this lesion and help in differentiating it from other tumors of similar histology. Furthermore, it also aids in planning treatment.

Anlotinib combined with Sintilimab is win-win cooperation for primary squamous cell carcinoma of the thyroid: A case report and literature review

Background

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare malignant tumor. The incidence rate of PSCCT is less than 1%. However, the diagnosis and treatment of PSCCT are limited. Surgical resection is considered to be one of the few effective intervention methods. In this article, we reported a case of taking tyrosine kinase inhibitors (TKIs) combined with immune checkpoint inhibitors (ICIs) for PSCCT.

Case summary

An 80-year-old male was admitted to our hospital with dyspnea, cough, wheezing, and hoarseness for a giant thyroid mass. He underwent bronchoscopy and tracheal stent implantation to alleviate the respiratory obstruction. Then he accepted right partial thyroid and right lymph node biopsy. Postoperative pathology revealed squamous cell carcinoma. Subsequently, he underwent an endoscopy to exclude upper gastrointestinal squamous cell carcinoma. Finally, he was diagnosed with PSCCT. The patient was tentatively treated with a combination of Anlotinib and Sintilimab. After two courses, the tumor volume significantly reduced in MRI images and shrank further after five courses of combined treatment. Unfortunately, the patient died of fulminant liver failure and autoimmune liver disease after 5-month-treatment.

Conclusion

TKIs combined with ICIs may be an effective and novel way for PSCCT treatment, but immune-related complications, especially liver damage, should be cared.

Primary squamous cell carcinoma of thyroid gland: 11 case reports and a population-based study

Background

Primary squamous cell carcinoma of thyroid gland (PSCCT) is a highly aggressive malignant tumor associated with a poor prognosis. Due to the rare case, there is a knowledge gap on the features of PSCCT. There is limited understanding of the treatment and molecular biology of this tumor. More genomic work and relevant perspective work need to be done.

Methods

We retrospectively reviewed the medical information of patients with PSCCT diagnosed from December 2009 to December 2020 at The First Affiliated Hospital of Guangxi Medical University. In addition, we conducted an electronic search of the paper in CNKI, Wanfang, VIP, PubMed, Embase, Web of Science, and ProQuest databases by recently updated articles. Survival analysis was conducted using the Kaplan–Meier method.

Results

There were only 11 patients met the study’s inclusion criteria in our institution. The patients ranged in age from 25 to 68 years old and female preponderance (M:F = 1:1.7). The median survival time was 6 months, and 1-year survival rate was 33.3%. Fifty-three patients’ individual data from 45 articles were selected for analysis. The median age at diagnosis was 63 years and female preponderance (M:F = 1:2.5). The commonest complaint was the anterior neck mass (77.3%), followed by hoarseness (32.1%). The median survival time was 9 months, and the overall 1-, 2-, and 5-year survival rate was 39.8%, 33.7%, and 26.9%, respectively. The log-rank method shows that age, tumor size, lymph node status, M stage, surgical range, and tracheal status were the relevant factors affecting the prognosis. In contrast, gender, treatment modality, and resection margin were not prognostic factors. On multivariable analysis, age and M stage were associated with overall survival.

Conclusion

The median overall survival was 6–9 months of PSCCT. Age and M stage are predictors of PSSCT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02814-9.

Clinical analysis of 13 cases of primary squamous-cell thyroid carcinoma

Objective

To analyze the clinical features, ultrasonographic manifestations, pathological features, treatment and prognosis of primary thyroid squamous cell carcinoma (PSCTC) and summarize the experience in diagnosis and treatment of this condition.

Methods

A retrospective analysis was conducted on patients who were admitted to Zhejiang Cancer Hospital from 2007 to 2021 due to thyroid nodules or thyroid malignant tumors that were ultimately confirmed by postoperative pathology as primary thyroid squamous cell carcinoma. We summarize the general situation, clinical information, laboratory examination, ultrasonic image characteristics, pathological examination, clinical treatment and prognosis of the patients.

Results

PSCTC is most often seen in older men and progresses rapidly. In laboratory tests, some patients had elevated levels of tumor markers (CA199, squamous cell carcinoma antigen level), thyroglobulin levels and tumor-related substances, but all these indicators lacked specificity. The ultrasound features of PSCTC are mainly hypoechoic, hard, substantial nodules with gross borders and a grade 1-2 blood flow signal, sometimes with signs of necrosis and calcification. In terms of treatment, PSCTC is mainly surgically resected, though some patients in this study underwent iodine-131 radiation therapy, local radiotherapy, and chemotherapy with unclear results. None of the patients survived for very long after treatment, but the prognosis of patients with highly differentiated squamous carcinoma was significantly better than that of patients with poorly differentiated squamous carcinoma. Papillary thyroid carcinoma may be one of the causes of PSCTC.

Conclusion

PSCTC is a malignant tumor with high malignancy and rapid clinical progression. Treatment options are mainly based on surgical resection and can be supplemented with radiotherapy and chemotherapy, but there is still a lack of a standardized treatment management system, and more cases and reports are needed to accumulate data.

Differences Between Cancer-Specific Survival of Patients With Anaplastic and Primary Squamous Cell Thyroid Carcinoma and Factors Influencing Prognosis: A SEER Database Analysis

PURPOSE

Anaplastic thyroid carcinoma (ATC) and primary squamous cell carcinoma of the thyroid (PSCCTh) have similar histological findings and are currently treated using the same approaches; however, the characteristics and prognosis of these cancers are poorly researched. The objective of this study was to determine the differences in characteristics between ATC and PSCCTh and establish prognostic models.

PATIENTS AND METHODS

All variables of patients with ATC and PSCCTh, diagnosed from 2004-2015, were retrieved from the Surveillance, Epidemiology, and End Results Program (SEER) database. Percentage differences for categorical data were compared using the Chi-square test. Kaplan-Meier curves, log-rank test, and Cox-regression for survival analysis, and C-index value was used to evaluate the performance of the prognostic models.

RESULTS

After application of the inclusion and exclusion criteria, a total of 1164 ATC and 124 PSCCTh patients, diagnosed from 2004 to 2015, were included in the study. There were no differences in sex, ethnicity, age, marital status, or percentage of proximal metastases between the two cancers; however, radiotherapy, chemotherapy, incidence of surgical treatment, and presence of multiple primary tumors were higher in patients with ATC than those with PSCCTh. Further cancer-specific survival (CSS) of patients with PSCCTh was better than that of patients with ATC. Prognostic factors were not identical for the two cancers. Multivariate Cox model analysis indicated that age, sex, radiotherapy, chemotherapy, surgery, multiple primary tumors, marital status, and distant metastasis status are independent prognostic factors for CSS in patients with ATC, while for patients with PSCCTh, the corresponding factors are age, radiotherapy, multiple primary tumors, and surgery. The C-index values of the two models were both > 0.8, indicating that the models exhibited good discriminative ability.

CONCLUSION

Prognostic factors influencing CSS were not identical in patients with ATC and PSCCTh. These findings indicate that different clinical treatment and management plans are required for patients with these two types of thyroid cancer.

Primary squamous cell carcinoma of the thyroid: a case report

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare and rapidly progressive malignancy that carries a poor prognosis. PSCCT is easily misdiagnosed as acute thyroiditis or as another thyroid malignancy. We have reported a 76-year-old woman who presented with progressive neck pain for 1 month. Thyroid function tests revealed subclinical thyrotoxicosis. Ultrasound disclosed a solid nodule with calcification in the right thyroid lobe. Laboratory findings included neutrophilic leukocytosis and an elevated erythrocyte sedimentation rate. The patient's condition was diagnosed as subacute thyroiditis, and she was treated with cefixime and ibuprofen. However, her treatment response was poor. She was then treated with oral prednisone. Her neck pain gradually resolved. The patient subsequently developed dysphagia, choking, dyspnea, and dysphonia with an insidious onset. Further examinations including computed tomography and painless gastroscopy revealed that the volume of the thyroid gland had increased significantly, extending to the anterior superior mediastinum. The trachea and esophagus were stenotic because of external compression. Partial thyroidectomy and tracheotomy were performed under extracorporeal membrane oxygenation. The diagnosis of PSCCT was established via histopathology and immunohistochemistry.

Primary Squamous Cell Carcinoma of the Thyroid: A Case Report and Literature Review About a Rare Entity

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare and aggressive neoplasm that accounts for less than 1% of all thyroid malignancies. Its incidence is higher in females in their fifth and sixth decades of life. The pathophysiology of PSCCT is still a subject of debate as squamous cells are generally absent in the thyroid gland under normal physiologic conditions. Immunohistochemistry is important for reaching a definite diagnosis as it helps to differentiate PSCCT from metastases from other primary sites. Clinically, PSCCT usually presents as a rapidly enlarging anterior neck mass. Surgical resection is the mainstay of treatment despite the lack of any standard guidelines for the same given the rarity of the disease. Adjuvant chemotherapy, radiotherapy, and targeted therapy continue to be of unclear benefit. We report a case of PSSCT in a male patient who presented with a rapidly enlarging neck mass.

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 squamous cell carcinoma of the thyroid gland successfully treated with surgical resection and adjuvant chemoradiotherapy

A 57-year-old woman presented with a 3-month history of an enlarging thyroid mass causing breathlessness and dysphagia. Cross-sectional imaging showed a thyroid tumour infiltrating the trachea and abutting the oesophagus. She underwent panendoscopy, total thyroidectomy and planned tracheal resection, but due to intraoperative findings, a staged procedure was planned instead. Histological analysis revealed a poorly differentiated squamous cell carcinoma (SCC) which was positive on paired box gene 8 (PAX8) immunostaining, suggesting a diagnosis of primary thyroid SCC. She subsequently underwent total laryngectomy and bilateral neck dissections followed by radiotherapy with concurrent cisplatin chemotherapy. The patient remains disease-free 22 months after treatment. Median overall survival is 10 months for macroscopically completely resected tumours. PAX8 immunostaining is a novel technique which helps with the diagnostic challenge of distinguishing between primary thyroid SCC and SCC metastatic to the thyroid from extrathyroidal sites. Complete surgical resection with adjuvant chemoradiotherapy may result in a favourable outcome despite conflicting reports in the literature.

Analysis of primary and secondary squamous cell carcinoma of the thyroid gland: a retrospective study

Background

Squamous cell carcinoma of the thyroid (SCCT) is a kind of rare malignant disease. This study aimed to analyse the clinical characteristics of patients with primary SCCT (PSCCT) and secondary SCCT (SSCCT).

Methods

The medical records of seventeen patients with PSCCT and six patients with SSCCT were reviewed. Clinical symptoms, ultrasound, and pathological characteristics were compared between the two groups.

Results

The mean age of diagnosis was approximately 56 years old in each group. The most common chief complaint of the patients was neck mass in both groups. The percentage of patients with cough (P=0.008) or weight loss (P=0.021) was higher in the SSCCT group than the PSCCT group. The mean size of the tumor in the PSCCT group was larger than that in the SSCCT group (3.382±2.011 vs. 1.950±0.794 cm, P=0.024). Papillary thyroid carcinoma (PTC) could be combined with or recur as PSCCT. Kaplan-Meier analysis indicated that the mean survival times after diagnosis were 17.053 months in the PSCCT patients and 13.500 months in the SSCCT patients. Multivariate survival analysis using a Cox regression model demonstrated that predictors of overall survival (OS) in PSCCT patients included age (P=0.020), enlarged cervical lymph node (P=0.017), radical operation (P=4.82×10^-3), and PTC (P=0.03).

Conclusions

SCCT is aggressive, with neck mass being the most common chief complaint. There were several different characteristics between PSCCT and SSCCT. PTC could be combined with or recur as PSCCT. Age, enlarged cervical lymph node, radical operation, and PTC were the predictors of OS in PSCCT patients.

Primary thyroid squamous cell carcinoma - a Scottish National Case Series

AIM

To present our national case series on primary thyroid squamous cell carcinoma (PTSCC) and add to the current literature about this rare and aggressive disease.

METHODS

Scottish pathology departments were contacted and asked to provide details of patients with the diagnosis of PTSCC from the last 10 years. Three patients were included.

RESULTS

Patients 1, 2 and 3 underwent surgical resection. Patients 1 and 3 went on to receive chemoradiotherapy. Patient 1 received nivolumab. Patient 1 died 10 months following diagnosis. Patient 2 and 3 are currently living with no recurrence, over two years post-diagnosis.

CONCLUSION

This case series has demonstrated an unusually good set of outcomes for a classically rapidly progressing disease with poor survival rates. This raises the question whether there is a subgroup of PTSCC associated with better outcomes and lower mortality. A patient-centred approach will give optimal patient management.

Prognostic Characteristics of Primary Squamous Cell Carcinoma of the Thyroid: A National Cancer Database Analysis

BACKGROUND

Primary squamous cell carcinoma of the thyroid (ThySCC) is a rare cancer, primarily described only in case reports. We aimed to characterize the prognosis of ThySCC and compare its oncologic behavior to other thyroid malignancies.

METHODS

The National Cancer Database was queried to identify patients with ThySCC, papillary, tall cell variant, poorly differentiated (PDTC), and anaplastic (ATC) subtypes of thyroid cancer treated from 2004 to 2015. Demographics, tumor characteristics, and treatments were compared by tumor type and assessed to identify independent predictors of overall survival (OS).

RESULTS

Of 123,684 patients included, 314 had ThySCC. ThySCC patients had a 5-year OS of 17.7%, more closely resembling ATC (8.3%) than PDTC or PTC. ThySCC and ATC patients had similar demographics, except ThySCC patients who were younger (68.0 vs. 70.2 years, p < 0.01). ThySCC tumors were smaller (mean 53.5 ± 45.7 vs. 69.5 ± 75.2 mm) with less frequent extrathyroidal extension (ETE) (64.0% vs. 73.8%), lymphovascular invasion (8.3% vs. 12.3%), and positive margins (22.0% vs. 28.3%) compared to ATCs (p < 0.05). ETE [HR 3.1 (95% CI 1.5-6.4), p < 0.05] and lymph node metastases [HR 2.2 (95% CI 1.2-4.0) p < 0.05] were independently associated with worse OS for ThySCC patients. Both ThySCC and ATC patients had similar surgical success rates, with R1 resection possible in 37.3% versus 35.0% of patients, respectively (p < 0.05). However, in contrast to ATC patients, adjuvant therapy was not associated with improved OS for ThySCC patients after complete resection.

CONCLUSIONS

ThySCC has a poor prognosis, similar to ATC, but with fewer aggressive features and no apparent survival benefit with adjuvant therapy after complete macroscopic surgical resection.

A Primary Squamous Cell Carcinoma of the Thyroid Presenting as the Anaplastic Thyroid Carcinoma: A Case Report

Background: Primary squamous cell carcinoma of the thyroid (PSCCT) is an uncommon malignancy that is difficult to diagnose and differentiate. There is no consensus for the early clinical, radiological, or ultrasonic identification of PSCCT before pathological changes are observed in patients. There is also no suitable treatment due to the absence of a definite diagnosis. Case Presentation: A 76-year-old female patient complained about a rapidly growing cervical mass, dyspnea, dysphagia, and a change in her voice. Based on the results of thyroid ultrasound, fine-needle aspiration, and plain and enhanced CT, the patient was initially diagnosed with anaplastic thyroid carcinoma (ATC). Thereafter, we removed the mass that was the patient's main complaint. The gross examination of the patient's symptoms also supported our previous diagnosis. However, her disease was finally diagnosed as PSCCT, according to the histopathology and immunohistochemistry findings of the mass. Conclusion: Our case highlights the need for a comprehensive framework in the management of PSCCT. The more auxiliary examinations (e.g., ultrasonographic, radiology, or biopsy examinations) we take, the more likely we are to identify this disease. Immunohistochemistry is currently the preferred examination for the diagnosis of PSCCT, while surgical resection combined with radio-sensitizing therapy and adjuvant chemotherapy is the main treatment method for PSCCT.

Treatment optimization and prognostic considerations for primary squamous cell carcinoma of the thyroid

Background

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare aggressive malignancy that usually presents in an advanced stage and has a poor prognosis. Our study aimed to investigate the clinical characteristics, treatment, and prognosis of PSCCT.

Methods

We retrospectively reviewed the medical information of patients with PSCCT diagnosed from January 2006 to May 2018 at Xiangya Hospital. Survival analysis was conducted using the Kaplan-Meier method, and Log-Rank tests were performed for statistical testing.

Results

We identified 12 patients with PSCCT (nine males and three females), accounting for only 0.19% of all thyroid cancer diagnosed during this time period. The median age of these patients was 59.5 years old and their symptoms included neck masses (n=5), hoarseness (n=2), dyspnea (n=1), dysphagia (n=1) and neck pain (n=1). Four patients were in stage IVA, five were stage IVB, and three patients were stage IVC. Six patients underwent comprehensive treatment (surgery + radiotherapy or surgery + radiotherapy + chemotherapy) and the remaining patients received radiotherapy and/or chemotherapy. The 6-month survival rate was 66.7%, compared to a 1-year survival rate of 25.0%, with a median overall survival time was 10.5 months. Kaplan-Meier analysis showed that the comprehensive treatment was superior to radiotherapy and/or chemotherapy (P=0.003).

Conclusions

PSCCT is a rare type of thyroid cancer that is highly invasive and has a poor prognosis. We show that a comprehensive treatment plan can significantly improve patient survival.

The Utility of Immunohistochemistry in Differentiating Metastatic Primary Squamous Cell Carcinoma of the Thyroid from a Primary Lung Squamous Cell Carcinoma

Primary squamous cell carcinoma of the thyroid gland (PSCCTh) and anaplastic thyroid carcinoma with extensive squamous differentiation are rare entities which pose a diagnostic challenge in determining the primary site when presented as metastases. The difficulty in confirming a thyroid primary is further compounded by the aggressive nature of these tumours which frequently present at advanced stages. We present a case in which the patient presented with a thyroid mass and a lung mass simultaneously. The risk of misinterpreting the site of primary tumour as lung is greatly increased because squamous cell carcinoma of lung is much more common than its thyroid counterpart. This case highlights the effectiveness of PAX-8 stain in determining the primary site of tumour when squamous cell carcinoma is found in both lung and thyroid gland.

Primary Squamous Cell Carcinoma in the Thyroid Gland: A Population-Based Analysis Using the SEER Database

OBJECTS

To evaluate prognostic factors and treatment outcomes of primary squamous cell carcinoma in thyroid (PSCCTh) over the past decades using a large national database.

METHODS

All patients diagnosed with PSCCTh between 1973 and 2015 were identified with the Surveillance, Epidemiology, and End Results Program (SEER) 18-registry database. Relevant clinical data were collected, and prognostic factors of overall survival (OS) and disease-specific survival (DSS) were analyzed.

RESULTS

This cohort study included 242 patients, accounting for 0.12% of all primary thyroid carcinomas from 1973 to 2015 nationwide. Of the patients with PSCCTh, 75% were older than 60 years at diagnosis. Patient age older than 60 years (HR 2.242, 95% CI 1.367-3.676, P = 0.001) and a tumor size larger than or equal to 50 mm (HR 1.479, 95% CI 1.011-2.165, P = 0.044) were independent negative prognostic factors. The univariate analysis suggested that the morphological subtype (OS, P = 0.033; DSS, P = 0.048), clinical treatment modality (OS, P < 0.0001; DSS, P < 0.0001), and T stage (OS, P = 0.004; DSS, P = 0.001) were important predictive factors for OS and DSS. In contrast, gender, race, year of diagnosis, geographic location, N stage, and M stage were not prognostic factors.

CONCLUSIONS

PSCCTh is a rare malignancy with an aggressive nature and poor prognosis. Survival is predicted by the treatment modality, patient age, T stage, tumor size, and morphological subtypes. This study showed that early diagnosis and complete surgical resection plus adjuvant radiation therapy were associated with a better outcome.

Small Cell Carcinoma: a Rare Subtype of Thyroid Cancer with Unanticipated Prognosis

The prognosis of small cell thyroid carcinoma (SCTC) in a large cohort has not been well reported in the literature. In this study, we analyzed the mortality of SCTC, in comparison to medullary thyroid cancer (MTC) and anaplastic thyroid cancer (ATC), based on the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute, to determine the prognosis of SCTC. Information regarding patients with a diagnosis of MTC, ATC, or SCTC, between 2004 and 2013, was acquired from the SEER database. Patient survival curves were assessed by Cox proportional hazards regression analyses, Kaplan-Meier analyses, and log-rank tests. In a Kaplan-Meier analysis of the entire cohort of thyroid cancer patients, cancer-specific survival declined sharply for patients with SCTC, but it declined more modestly for patients with MTC. The cancer-specific survival was not significantly different between SCTC and ATC. Unadjusted Cox regression analysis showed that SCTC had a higher cancer-specific mortality than MTC but a similar prognosis as ATC. SCTC showed a higher cancer-specific mortality than MTC and ATC after adjustments for various confounding factors. SCTC was found to have a more highly lethal clinical course than MTC and had a similar death rate to ATC. Therefore, we recommend that aggressive, radical treatment like surgery or radiation should be performed for these patients.

Primary Squamous Cell Carcinoma of the Thyroid

Background: Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare malignancy of the head and neck, with fewer than 60 cases reported in the literature. We report a case of PSCCT and provide a brief review of the literature. Case Report: A 66-year-old female with a history of a hemithyroidectomy for a benign thyroid lesion presented with 3 months of progressively worsening compressive symptoms and shortness of breath. Physical examination revealed right-sided thyromegaly and right-sided true vocal fold immobility. Preoperative imaging with ultrasound and computed tomography scan confirmed an enlarged right thyroid, as well as right anterior cervical lymphadenopathy, subglottic stenosis, and bilateral pulmonary nodules. Fine needle aspiration of the thyroid was suggestive of carcinoma. Intraoperative findings of gross tracheal invasion during a planned completion thyroidectomy prompted limited resection and impromptu tracheotomy. Histopathologic and immunohistochemical evaluation confirmed a squamous cell carcinoma of thyroid origin. Further oncologic workup with core lung biopsy and positron emission tomography scan demonstrated metastasis to the lung and cervical spine. Palliative chemotherapy was begun, but the patient died 1 week into therapy. Conclusion: PSCCT is a rare but aggressive malignancy of the head and neck. Histopathologic and immunohistochemical evaluations are essential for diagnosis. While locoregional surgery and radiation therapy may improve the length of survival, the prognosis of patients with PSCCT is poor. Physicians should be mindful of this unique but deadly disease process, as early diagnosis and rapid treatment initiation are essential to optimize treatment outcomes.

Biological role and clinical value of miR-99a-5p in head and neck squamous cell carcinoma (HNSCC): A bioinformatics-based study

MicroRNAs (miRNAs) are confirmed to be tumor promoters or suppressors in multiple squamous cell carcinomas (SCCs). miR‐99a‐5p has been demonstrated to be downregulated in cancerous tissues, but its functional role in head and neck SCC (HNSCC) and its mechanism of action have not been fully elucidated. Here, we studied the expression of miR‐99a‐5p in HNSCC and performed a clinical value assessment and then extracted mature expression data from The Cancer Genome Atlas (TCGA) and microarrays from Gene Expression Omnibus (GEO). Furthermore, biological analysis was constructed via online prediction tools. The results revealed that miR‐99a‐5p expression was markedly lower in HNSCC tissues than in normal tissues, which also showed significance in the prognosis of HNSCC. However, its diagnostic value could not be verified due to the lack of body fluid samples. Additionally, miR‐99a‐5p was expressed at higher levels in patients with low histological grade neoplasms than those with high histological grade neoplasms. The age of the patient might also be a possible clinical parameter affecting miR‐99a‐5p expression. Furthermore, miR‐99a‐5p significantly influenced HNSCC progression by regulating the PI3K‐Akt signaling pathway, in which the key target genes were upregulated in 519 HNSCC tissues compared to 44 normal tissues, as determined by the Gene Expression Profiling Interactive Analysis (GEPIA). In conclusion, our study may provide insights into the expression and mechanism of miR‐99a‐5p in HNSCC. Further studies are required to elucidate the role of miR‐99a‐5p and its potential clinical applications for HNSCC.