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

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.

[Primary squamous cell carcinoma of the thyroid gland]

Primary squamous cell carcinoma (SCC) of the thyroid gland is now considered as a member of the anaplastic thyroid carcinoma group based on the latest version of the WHO tumor classification. It is a very rare entity, the prognosis is adverse with a short survival time. The aim of this article is to emphasize the therapeutic complexity of this disease. A 68-year-old woman presented with rapidly growing right-sided neck mass with hoarseness and compressive symptoms. Physical examination revealed a hard fixed tumor with right-sided vocal cord palsy. Fine-needle aspiration cytology revealed a case of SCC in the location of the thyroid gland, imaging studies excluded the possibility of other primary malignancies. Surgical intervention was performed aiming the total removal of the tumor. Histopathological result confirmed the diagnosis of SCC of the thyroid. Finally the patient died during the palliative radiation therapy. SCC of the thyroid gland is a great challenge for both the surgeon and the multidisciplinary team to come up with the best treatment option which is suitable for the patient due to its unfavorable prognosis. Because of the poor response to the radiation and chemotherapy, complete surgical removal and the identification of any possible targetable molecular pathological change play a unique role in the therapy. Orv Hetil. 2023; 164(39): 1556-1559.

Primary and metastatic squamous cell carcinoma of the thyroid gland: Two case reports

This study reports two cases of squamous cell carcinoma of the thyroid (SCCT) presenting as the thyroid goiter, involving one case of primary squamous cell carcinoma originating from the thyroid (PSCCT) and the other case of secondary SCCT of the thyroid. A retrospective analysis of the clinical and pathological findings was done in this study report. In case 1, the thyroid ultrasound showed multi-hypoechoic well-defined nodules, labeled as 3 using Thyroid Imaging Reporting and Data System, measuring 34.1 mm × 28.9 mm × 30.3 mm and 26.5 mm × 22.2 mm × 23.9 mm in the left in the right lobar thyroid, respectively. The patient underwent surgery and was histologically diagnosed with PSCCT. In case 2, the thyroid ultrasound showed a 25.2 mm × 22.2 mm × 18.8 mm hypoechoic nodule in the right lobar thyroid. The patient underwent a frozen biopsy, the results of which increased suspicion of squamous cell carcinoma. A frozen biopsy was followed by an endoscopic evaluation that detected an ulcerative mass measuring 3.0 cm within the mucosa of esophagus. Due to a scarcity of cases, SCCT is a great challenge for the pathologists and the managing team to come up with the best treatment strategy for the patients.

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.