primary squamous cell carcinoma ( scc ) of the thyroid gland is a very rare entity representing < 1% of all primary carcinomas of the thyroid gland [ 1 , 2 ] . only a few cases are reported in the international literature and it is described as a very aggressive tumor with a poor prognosis . the aim of this study is to report the case of a scc of the thyroid gland in a 65-year - old woman , emphasizing the postoperative complications and poor prognosis of these patients . a 65-year - old female patient with a 20-year history of thyroid goiter was admitted to our clinic due to progressive neck enlargement for the past 2 months . her weight was stable and she was a smoker for 26 years ( 1945 years old ) . on physical examination , her vital signs were stable . there was no palpable cervical lymphadenopathy , and examination of chest , heart , nervous system and abdomen was normal . thyroid ultrasound was performed revealing a mass of the left lobe measuring 4.5  5.2  5.9 cm with retrosternal extension . fine needle aspiration ( fna ) cytology was performed which showed no definite signs of malignancy . 1 ) was accompanied by six enlarged lymph nodes that seemed to be suspicious during the surgical procedure . no infiltration of adjacent organs ( esophagus , trachea and carotid ) was noted intraoperatively . the patient 's hospitalization was uneventful and was discharged on the second postoperative day . figure  1:surgical specimen : thyroid gland with an enlarged left lobe ( retrosternal extension ) . histological examination showed the presence of moderately differentiated scc which infiltrated mainly the left and focally the right lobe of the thyroid gland ( fig .  2 ) . large areas of fibrosis with hyalinization , calcification , bone formation and foci of necrosis were observed . possibly due to the formerly mentioned lesions , the cytological aspiration was negative for malignancy . sections from other sites of the thyroid showed goiter - like lesions with no signs of hashimoto 's thyroiditis or any other neoplasm . on the basis of the above results , figure  2:h / e 100 section from the left lobe of the thyroid gland showing infiltrative scc . h / e 100 section from the left lobe of the thyroid gland showing infiltrative scc . a month after surgery esophagogastroduodenoscopy was performed , due to the presence of enlarged lymph nodes in the left supraclavicular fossa , with no significant findings . ct of the neck and thorax revealed a 6.2-cm - diameter mass infiltrating the trachea and the surrounding soft tissue ( fig . 3 ) , as well as the presence of lymph nodes in the mediastinum and metastatic foci in the right lung ( fig .  4 ) . mri of the head and neck showed the presence of stenosis in the subglottic part of the larynx , the upper part of the trachea and extensive lymphadenopathy in the left neck , with enlargement of isthmus and left lobe areas . finally , one and a half month after surgery , tracheostomy was performed due to airway compromise . figure  3:a ct scan showing a 6.2-cm mass pressuring and infiltrating the trachea and surrounding soft tissue . a ct scan showing a 6.2-cm mass pressuring and infiltrating the trachea and surrounding soft tissue . a ct scan showing metastasis to the right lung . mg / kg once a week with concomitant radiotherapy , which was abruptly terminated because of toxicity . patient died 5 months after the surgery due to airway compromise ( direct infiltration of tumor to trachea causing airway obstruction ) . a primary scc of the thyroid is rare , representing < 1% of all primary thyroid carcinomas [ 1 , 2 ] . due to its rarity , only few case reports are reported in the international literature . scc affects usually older patients between the fifth and sixth decade and is usually associated with a history of goiter . in the majority of cases , the patients present at the time of diagnosis with a rapidly enlarged neck mass , followed by symptoms of infiltration and compression of adjacent neck structures ( dyspnea and hoarseness ) . carcinoma showing thymus - like elements ( castle ) disease of the thyroid gland , anaplastic thyroid carcinoma and metastasis from adjacent organs should be considered in the differential diagnosis . first , the embryonic nest theory suggests that the squamous cells are derived from the remnants of thyroglossal duct or the epithelium of the thymus . secondly , the metaplasia theory suggests that these cells present as a result of environmental stimuli ( inflammation and hashimoto 's thyroiditis ) . thirdly , the de - differentiation theory suggests that existing papillary , follicular , medullary and anaplastic thyroid carcinoma de - differentiate into scc . surgical excision of primary thyroid scc with adjuvant radiotherapy and chemotherapy is the optimal treatment . however , many studies suggest that it is relatively radio - resistant and has poor response to chemotherapy [ 4 , 8 ] , leaving complete surgical excision the only chance of prolonging survival of these patients . patients with primary thyroid scc have a very poor prognosis and the main cause of death is respiratory interference by direct invasion or compression of the trachea . cho et al . , recently , performed a systematic review and individual participant data meta - analysis regarding primary scc of the thyroid gland . according to this meta - analysis ( 89 patients ) , the mean age of diagnosis was 63 years ( range , 2490 ) , a female preponderance ( m : f = 1:2 ) was noted and the commonest complaint was the anterior neck mass . it was noted that predictability of diagnosis with fine needle aspiration cytology was accurate in less than one - third of the patients and more than half of cases had been diagnosed as papillary thyroid carcinoma or were non - diagnostic ( as in our case ) . complete surgical resection ( ro ) of the tumor was the only significant prognostic factor in multivariable analysis , and the benefit of adjuvant treatment was not proved . moreover , the prognosis of these patients was very poor ( only 20% in 3 year survival rate ) . scc of the thyroid gland is a very rare and aggressive entity with poor prognosis . complete surgical resection ( ro ) of the tumor is the only significant prognostic factor , whereas efficacy of adjuvant treatment ( chemo- and radiotherapy ) remains controversial in the international literature . a fatal outcome is usually a result of its complications , due to loco - regional spread of the disease to adjacent organs and structures .
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 .