Primary squamous-cell carcinoma of the thyroid gland: new evidence in support of follicular epithelial cell origin

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.

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.

Primary squamous cell carcinoma of the thyroid treated with concurrent chemoradiation and palliative immunotherapy: a case report

BACKGROUND

Primary squamous cell carcinoma of the thyroid is a very rare malignancy with aggressive growth and poor prognosis. There is currently no consensus for treatment modality, however, most patients with primary squamous cell carcinoma of the thyroid are treated with surgery and adjuvant chemoradiation.

CASE PRESENTATION

We report a rare case of primary squamous cell carcinoma of the thyroid in a 68-year-old White male who underwent chemoradiation and palliative immunotherapy after declining surgery. He was treated with intensity-modulated radiation therapy to 70 Gy in 35 fractions, with concurrent carboplatin-paclitaxel and palliative pembrolizumab. Local thyroid disease recurrence occurred at 6 months post-chemoradiation, and the patient died at 16 months post-chemoradiation.

CONCLUSIONS

This is the first case report demonstrating the use of pembrolizumab as palliative therapy for primary squamous cell carcinoma of the thyroid. Our study also highlights the importance of chemoradiation in decreasing primary mass size and immunotherapy in preventing metastatic disease progression.

Squamous Differentiation in the Thyroid: Metaplasia, Neoplasia, or Bystander?

Background. Squamous differentiation within the thyroid is seen in a variety of settings. Squamous epithelium is non-native to the thyroid, and its debated origins span reactive metaplasia and developmental/embryologic remnants. Despite a lack of clarity as to its evolution, squamous epithelium may be associated with both neoplastic and non-neoplastic processes. Methods. Thyroid pathology reports spanning a 30-year period were reviewed for terms indicating squamous features. Associated diagnostic and clinical information was collated. Results. Four hundred and twenty seven of 17,452 (2.4%) thyroid surgical pathology cases during this period utilized terminology indicating squamous differentiation including 243 malignant (58%) and 178 benign (42%) diagnoses. There were 111 (26%) primary thyroid malignancies with squamous differentiation, 116 (28%) malignancies of non-thyroid origin including local extension from nearby cancers, and 16 (4%) malignancies of uncertain primary. Most benign lesions were non-neoplastic (84%). The minor subset representing benign neoplasia was interpreted as secondary reactive changes. Conclusion. While squamous differentiation is seen routinely in the thyroid, it is most commonly reported in malignancy. For primary thyroid malignancies reported to demonstrate a squamous component, biologically aggressive tumors were overrepresented. Available evidence suggests that multiple pathways may contribute to the presence of squamous epithelium in the thyroid including metaplasia of mature follicular cells, development from established embryonic remnants, or inception in putative, incompletely characterized stem-like cells. Our retrospective review presents an institutional landscape from which further investigation into the frequency and unique histologic and molecular context of intrathyroidal squamous differentiation as a driver or terminal event in thyroid pathophysiology.

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.

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.

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.

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.

The Expressions of Keratins and P63 in Primary Squamous Cell Carcinoma of the Thyroid Gland: An Application of Raman Spectroscopy

Purpose

Primary squamous cell carcinoma is a rare malignancy in the thyroid gland (SCCTh). The overall prognosis of this carcinoma is poor. This study aimed to explore the application of Raman spectroscopy in investigating the expression of CK5/6 and P63 in SCCTh.

Patients and Methods

Tissues of the SCCTh and adjacent normal thyroid, as well as blood serum, were collected from a patient with pathology-confirmed SCCTh. Whole genome sequencing analysis was performed with the tissue of the SCCTh. The expressions of keratins and TP53 family gene were investigated by the Raman spectroscopy in tissues of the SCCTh and adjacent normal thyroid. The serum was also investigated by the Raman spectroscopy for the expression of keratins and TP53 family gene.

Results

The whole genome sequencing analysis identified the mutation of the TP53 gene (42%) in the tissues of SCCTh. Accordingly, the Raman spectra analyses showed higher expression of keratins and TP53 family gene in the tissues of SCCTh compared with that in the adjacent normal thyroid. Raman spectra analyses of the serum of the patient also showed the expressions of the keratins and TP53 family gene.

Conclusion

The expressions of the keratins and TP53 are different in the tissues of SCCTh and adjacent normal thyroid, and the difference could be identified with high sensitivity by the Raman spectra analyses.

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.

Primary Squamous Cell Carcinoma of the Thyroid: Immunohistochemical Profile and Literature Review

Background

Squamous cell carcinoma accounts for 1% of primary thyroid malignancies and is characterized by a rapidly unfavorable outcome.

Case Presentation

A 64-year-old woman presented with a painless mass in the left neck, coexisting with thyroid goiter. Total thyroidectomy with lymphadenectomy was performed and a primary thyroid squamous cell cancer was confirmed histo-logically after excluding any other possible primary malignancies. The tumor's immunohistochemical profile was explored using a large panel of antibodies. The tumor featured a positive immunoreaction to cytokeratins 7–19 and to squamous cell carcinoma antigen. Low-molecular-weight cytokeratins 5–6 and epithelial membrane antigen were also expressed. The neoplasm's proliferative index (Mib1) was 60%. No immunostaining was detected for cytokeratins 10–20, thyroglobulin, TTF-1, CD5, galectin-3 or p53.

Conclusions

This case of primary thyroid squamous cell carcinoma immunohistochemically profiled using a large panel of immunoreactions may offer useful information on the histological differentiation of thyroid squamous cell carcinoma from other (uncommon) thyroid carcinomas and the distinction between primary and secondary thyroid cancers.

EGFR Polysomy in Squamous Cell Carcinoma of the Thyroid. Report of Two Cases and Review of the Literature

Aims and background

Primary squamous cell carcinoma of the thyroid gland (PSCCT) is an uncommon malignancy characterized by a poor prognosis. A radical surgical approach combined with radiotherapy or chemotherapy is the generally accepted treatment for this tumor. The epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor modulating the cell proliferation and biological progression of many human epithelial tumors. The EGFR overexpression in PSCCT suggests an additional therapeutic option for the treatment of this tumor.

Methods and study design

The clinicopathological features and immunohistochemical profiles of two cases of primary squamous cell carcinoma of the thyroid in a 66-year-old and an 83-year-old woman are presented. EGFR status was valued in both cases.

Results

Overexpression of EGFR protein was detected in 50% and 75% of the tumor cell membranes. EGRF gene polysomy was detected in both tumors.

Conclusions

Pharmaceuticals targeting EGFR may help to provide the rationale for an additional, novel therapeutic option for this rare tumor, especially when other therapeutic options have been exhausted.

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. Initial assessment and follow-up using 18F-FDG PET/CT

Squamous cell carcinoma of thyroid is an uncommon, very aggressive neoplasm, having a poor prognosis and poor response to chemotherapy and radiotherapy. Surgery is the initial treatment of choice, although it often presents as a widespread disease at the time of diagnosis, usually with cervical swelling that causes most of the symptoms due to local infiltration or metastasis. Local infiltration from adjacent tumour and metastatic disease needs to be excluded from other primary epidermoid carcinomas, in order to make a correct diagnosis. This also requires the typical cytokeratin pattern seen in histological studies. The case is presented of a 53 year-old man with a medical history of hepatocarcinoma, with a cervical hypermetabolic lesion detected in an ¹⁸F-FDG PET/CT performed to exclude widespread disease. The follow-up of this lesion with this technique and its usefulness is also described.

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 diagnosed as anaplastic carcinoma: failure in fine-needle aspiration cytology?

A case of primary squamous-cell carcinoma (SCC) of the thyroid which had been initially diagnosed as an anaplastic carcinoma (ATC) is described: female, 73 years old, with a fast-growing cervical nodule on the left side and hoarseness for 3 months. Ultrasonography showed a 4.5 cm solid nodule. FNA was compatible with poorly differentiated carcinoma with immunoreactivity for AE1/AE3, EMA. Thyroidectomy was performed. Histopathological examination showed a nonencapsulated tumor. Immunohistochemistry disclosed positivity for AE1/AE3, p53,p63, and Ki67. The diagnosis was ATC. A second opinion reported tumor consisting of squamous cells, with intense inflammatory infiltrate both in tumor and in the adjacent thyroid, with final diagnosis of SCC, associated with Hashimoto thyroiditis. No other primary focus of SCC was found. Patient has shown a 48-month survival period. Clinically, primary SCCs of the thyroid and ATCs are similar. The distinction is often difficult particularly when based on the cytological analysis of FNA material.

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.

Laryngotracheal presentation of anaplastic thyroid carcinoma with squamous differentiation: seven cases demonstrating an under-recognized diagnostic pitfall

AIMS

To describe a series of anaplastic thyroid carcinomas that mimicked primary head and neck squamous cell carcinoma (HNSCC) by virtue of both morphology and clinical presentation.

METHODS AND RESULTS

Seven cases were identified in a 15-year period where a biopsy of an airway lesion that appeared to be squamous cell carcinoma was, in fact, anaplastic thyroid carcinoma. The tumours had squamous and/or spindle cell morphology, with only the squamous component being apparent in the airway biopsy. Some tumours arose within metaplastic (n = 3) or atypical (n = 3) epithelium, supporting the diagnosis of a primary mucosal tumour. Positive PAX8 (n = 5) and TTF-1 (n = 4) staining was identified.

CONCLUSIONS

An endotracheal presentation of anaplastic thyroid carcinoma with squamous morphology may be misdiagnosed as a primary head and neck squamous cell carcinoma. PAX8 and TTF-1 expression are helpful in making the distinction, but the problem lies in suspecting a thyroid carcinoma in what appears to be a straightforward diagnosis of HNSCC.

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.

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

BACKGROUND

Primary squamous cell carcinoma (SCC) of the thyroid gland is a rare malignancy that presents with advanced disease and poor prognosis.

METHODS

A 75-year-old woman with a history of Hashimoto thyroiditis presented with 6 months of dysphagia and stridor. Imaging revealed a thyroid mass invading the larynx. Primary SCC of the thyroid was diagnosed by histopathologic and immunohistochemical evaluation. Total thyroidectomy, total laryngectomy, bilateral modified neck dissection, and adjuvant radiotherapy (RT) were performed. Radiologic follow-up at 21 months demonstrated no disease and total length of survival was 31 months.

RESULTS

Despite an aggressive T4aN0M0 tumor, survival in this case was more than double the median survival rate previously reported. Concomitant Hashimoto thyroiditis is rare and histopathologic and immunohistochemical evaluation is imperative for an accurate diagnosis.

CONCLUSION

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 pure squamous cell carcinoma of the thyroid: report and histogenic consideration of a case involving a BRAF mutation

Primary squamous cell carcinoma of the thyroid (SCC-T) is extremely rare. Its clinical presentation is similar to that of anaplastic carcinoma. Metastasis or extension from the head and neck area should be ruled out, as patients with SCC-T have a poorer prognosis than patients who have a thyroid extension from an adjacent tumor. An 87-year-old man presented with a longstanding painless mass in the right thyroid and had experienced 2 months of pain upon swallowing. A right lobectomy was performed with resection of thyroid cartilage, cricoid cartilage, a portion of the first to third tracheal ring and the right neck lymph node. A histological examination revealed pure SCC. The tumor cells showed diffuse immunoreactivity to CK5/6, CK19 and p63. Immunoreactivity to EMA and p53 was focally positive. TTF-1, galectin 3 and thyroglobulin immunoreactivity was restricted to the non-neoplastic thyroid tissue. Both tumor cells and non-neoplastic follicular cells were negative for CD5. The MIB-1 index was 36%. DNA extracted from the tumor identified a BRAF V600E mutation in exon 15 and a BRAF G468A mutation in exon 11, whereas DNA from non-tumorous cells did not contain a mutation. These molecular findings may suggest a direct transformation from papillary carcinoma to SCC-T.

Fine needle aspiration biopsy of three cases of squamous cell carcinoma presenting as a thyroid mass: cytological findings and differential diagnosis

OBJECTIVE

Primary squamous cell carcinomas of the thyroid gland are extremely rare, comprising about 1% of thyroid malignancies. Although squamous cell carcinomas are readily identified as such on aspiration cytology in the majority of cases, the differentiation of primary versus metastatic tumour might not always be easy. Herein, we report three cases of squamous cell carcinomas involving the thyroid gland.

METHODS

Fine needle aspiration cytology (FNAC) was performed in three patients with a thyroid mass using standard guidelines. Smears were stained with Diff-Quik and Papanicolaou stains.

RESULTS

Two patients were male and one was female, aged 59, 45 and 35 years, respectively. In all three patients a thyroid mass was present. FNAC smears in all cases showed cytological features of squamous cell carcinoma including keratinization and necrosis. After clinical and cytological correlation, one case appeared to be primary, one case metastatic, and in the third case no additional clinical information or biopsy follow-up was available for further characterization.

CONCLUSIONS

Because primary squamous cell carcinoma of the thyroid is a rare finding, metastatic squamous cell carcinoma should always be excluded first. Metastatic disease usually presents in the setting of widespread malignancy, therefore a dedicated clinical and radiological investigation is necessary in these cases. In both clinical scenarios the patient's prognosis is poor.

Squamous cell carcinoma of the thyroid gland: primary or secondary disease?

OBJECTIVE

To review the aetiopathogenesis, clinical characteristics, immunohistochemical profile, prognosis and treatment options for primary thyroid squamous cell carcinoma, and to compare it with squamous cell carcinoma metastatic to the thyroid, thus providing the reader with a framework for differentiating primary and secondary disease.

METHOD

Review of English language literature from the past 25 years.

SEARCH STRATEGY

A search of the Medline, Embase and Cochrane databases (April 1984 to April 2009) was undertaken to enable a comprehensive review.

RESULTS

After applying strict criteria for the diagnosis of primary thyroid squamous cell carcinoma, 28 articles were identified reporting 84 cases. When reviewing secondary thyroid squamous cell carcinoma, we only analysed cases of squamous cell carcinoma metastatic to the thyroid gland, and found 28 articles reporting 78 cases.

CONCLUSION

It is possible to differentiate between primary and secondary thyroid squamous cell carcinoma, on the basis of combined evidence from clinical examination and endoscopic, pathological and radiological evaluation. Such differentiation is important, as the prognosis for primary squamous cell carcinoma is uniformly poor irrespective of treatment, and the most suitable option may be supportive therapy. Treatment for secondary squamous cell carcinoma of the thyroid varies with the site and extent of spread of the primary tumour.

Combined therapy for thyroid squamous cell carcinoma

BACKGROUND.: Squamous carcinoma of the thyroid is a rare aggressive disease, resulting in poor prognosis. METHODS AND RESULTS.: We combined cisplatin with paclitaxel on a weekly basis as induction therapy, achieving a high cumulative dose, in a patient with squamous cell tumor of the thyroid with arterial encasement. After surgery, pathologic examination confirmed a complete resection of the primary tumor with clear margins, revealing a successful induction treatment with chemotherapy. CONCLUSIONS.: Our patient now has a recurrence-free survival of >20 months, longer than the mean survival described in the literature.

Primary squamous cell carcinoma of the thyroid: report of three cases

We report three cases of squamous cell carcinoma of the thyroid, which is an unusual malignant tumor that needs to be distinguished from other thyroid pathologies due to its aggressive behaviour. Three men, with an average of 63 years old, presented with progressive enlargement in the neck, hoarse voice or weight loss. Physical and radiological examinations revealed clues where malignancy was suspected and surgical resections were performed. Histopathological examination of the specimens was diagnosed as squamous cell carcinoma. Proper workup excluded the possibility of any primary site of SCC other than the thyroid. All patients died within 5 months. Adjuvant therapy evaluation is still inconclusive. Complete surgical resection still remains the primary choice for cure. We believe that radical resection with clear surgical margins followed by adjuvant chemo-radiation therapy is a curative strategy for achieving any chance of long-term survival.

Collision tumor of the thyroid: follicular variant of papillary carcinoma and squamous carcinoma

BACKGROUND

Collision tumors of the thyroid gland are a rare entity. We present a case of a follicular variant of papillary carcinoma and squamous carcinoma in the thyroid. To the best of our knowledge, this is the first documentation of a collision tumor with a papillary carcinoma and a squamous carcinoma within the thyroid gland. The clinicopathological features and immunohistochemical profile are reported. The theories of origin, epidemiology and management are discussed with a literature review.

CASE PRESENTATION

A 65 year old woman presented with a large thyroid swelling of 10 years duration and with swellings on the back and scalp which were diagnosed to be a follicular variant of papillary thyroid carcinoma with metastasis. Clinical examination, radiology and endoscopy ruled out any other abnormality of the upper aerodigestive tract. The patient was treated surgically with a total thyroidectomy with central compartment clearance and bilateral selective neck dissections. The histopathology revealed a collision tumor with components of both a follicular variant of papillary carcinoma and a squamous carcinoma. Immunohistochemical analysis confirmed the independent origin of these two primary tumors. Adjuvant radio iodine therapy directed toward the follicular derived component of the thyroid tumor and external beam radiotherapy for the squamous component was planned.

CONCLUSION

Collision tumors of the thyroid gland pose a diagnostic as well as therapeutic challenge. Metastasis from distant organs and contiguous primary tumors should be excluded. The origins of squamous cancer in the thyroid gland must be established to support the true evolution of a collision tumor and to plan treatment. Treatment for collision tumors depends upon the combination of primary tumors involved and each component of the combination should be treated like an independent primary. The reporting of similar cases with longer follow-up will help define the epidemiology, biology and establish standardized protocols for treatment of these extremely rare tumors.

A patient with primary squamous cell carcinoma of the thyroid intermingled with follicular thyroid carcinoma that remains alive more than 8 years after diagnosis

Primary squamous cell carcinoma of the thyroid is an extremely rare tumor with a highly aggressive clinical course. We report here on a patient with primary squamous cell carcinoma of the thyroid who remains alive more than 8 years after diagnosis. A 56-year-old man presented with a hoarse voice and a rapidly progressing mass on the right side of the thyroid gland. The patient underwent a total thyroidectomy without neck lymph node dissection. Histopathologic findings revealed primary squamous cell carcinoma combined with follicular carcinoma of the thyroid. The tumors metastasized to the cervical lymph nodes, thoracic spine and lung. He underwent 5000 rads of adjuvant radiotherapy to the neck. TSH suppressive therapy with L-thyroxine was administered alone rather than radioactive iodine therapy or chemotherapy. The patient's clinical course has been remarkable over the first 7 years; he has remained stable except for a transient paraplegia due to nerve compression. The patient underwent colectomy for the diagnosis of a colon cancer. Recent evaluation has revealed a new lesion in the lung; this was diagnosed as metastatic follicular carcinoma originating from the thyroid. High dose radioactive iodine therapy was administered, and he remains alive in stable condition.

Primary squamous cell carcinoma of the thyroid: report of ten cases

OBJECTIVES

To define the clinical and pathologic characteristics of primary squamous cell carcinoma of the thyroid (PSCCT), a rare tumor, and compare it to the more common secondary squamous cell carcinoma of the thyroid (SSCCT).

MATERIALS AND METHODS

A search of tumor registry and medical archives of our institution identified 24 cases of squamous cell carcinoma involving the thyroid in a 25-year period (1978-2003). Medical records and pathology specimens were reviewed. This investigation did not reveal other primary sites in 10 (PSCCT). Other primary sites were identified in 14 patients (SSCCT). Immunostaining was done for thyroglobulin, cytokeratin (7 and 19), thyroid transcription factor (TTF), calcitonin, p21, MIB-I, and p53.

RESULTS

All 10 PSCCTs presented with a rapidly enlarging neck mass. Excision was possible in 8. PSCCT had the following features on immunostaining: keratin (8/8, 100%), thyroglobulin (5/8, 62.5%), TTF positive (3/8, 37.5%), and calcitonin negative. Cytokeratins 7 and 19 were diffusely and strongly positive in the PSCCT. Expression of putative biomarkers p21, MIB-I, and p53 was elevated with PSCCT cells showing mean expression of 36%, 48%, and 39%, respectively, compared to less than 5% in non-neoplastic tissues. The mean survival from diagnosis was 8.6 months. All patients died of disease. Airway compromise was the cause of death in the majority. In SSCCT, positivity for thyroglobulin and TTF was not seen. The locations of the primary sites were: larynx (7; 50%), trachea (4; 29%), esophagus (2; 14%), and oral cavity (1; 7%). At last follow-up, 4 were alive with mean survival of 5.5 years. Six had cancer-related mortality with mean survival of 46 months.

CONCLUSION

PSCCT is an aggressive cancer with death occurring within the first year in most patients. The prognosis for patients with PSCCT is worse than SSCCT. p21, MIB-I, and p53 are overexpressed in PSCCT. Thyroglobulin and TTF can show focal positivity in PSCCT distinguishing it from SSCCT.

Thyroid cancer review 3: management of medullary and undifferentiated thyroid cancer

This is the last of the three review articles dealing with thyroid cancer. Over 90% of thyroid cancer is of the differentiated type associated with a very good 10-year disease-free survival rate. In contrast, the rare forms of thyroid cancer which comprise medullary thyroid cancer arising from parafollicluar C cells, Hurthle cell carcinoma, anaplastic carcinoma, thyroid lymphoma and squamous cell carcinoma are typically associated with a poorer survival rate. Management is based upon small retrospective cohort studies.

Metastatic disease of bronchial carcinoma in a thyroid nodule: a case report

Metastatic spread of solid tumors to the thyroid is a rare finding in patients with thyroid nodules. The most frequent sites of the primary tumor include the kidney, breast and lung. Work up of patients with a cold thyroid nodule and a history of cancer should therefore rule out other metastasizing cancer or recurrence of the previous tumor using fine-needle aspiration of the thyroid mass. We report the case of a 64-year-old male with metastatic spread of a bronchial carcinoma to the thyroid and the management of this case.