Primary Squamous Cell Carcinoma of the Thyroid: A Case Report and Review of the Literature

Abstract

Primary squamous cell carcinoma of the thyroid or Herrenschmidt tumor is an extremely rare entity that accounts for less than 1% of all types of thyroid neoplasms. Moreover, it has an aggressive behavior and unfavorable prognosis that resembles anaplastic thyroid carcinoma. The management of this tumor is mainly based on radical surgery. However, various other therapeutic approaches have been used, either exclusively or in combination with surgery. We report the case of a 60 years female patient, who presented with a cervical mass, that has been evolving for 2 months, causing intermittent dysphonia and dyspnea. Computed Tomography of the neck showed a goiter involving the isthmus and right lobe of the thyroid, infiltrating the aerodigestive tract, filling the thoracic inlet, and associated with cervical lymph nodes. Biochemical tests including serum thyroid-stimulating hormone (TSH), T4, thyroglobulin, and calcitonin were quite normal. An Echoguided thyroid biopsy was performed, which the histological and immunohistochemical study revealed a squamous cell carcinoma of the thyroid. The metastatic workup was negative. The case was discussed in a multidisciplinary deliberation meeting that concluded that the tumor is unresectable, and the patient was proposed for palliative radiotherapy and supportive treatment. The post-therapeutic follow-up was marked by size progression of the neck mass and persistent dyspnea. The patient died of airway compromise after 4 months.