Primary Squamous Cell Carcinoma of Thyroid: A Rare Entity

Paraneoplastic Manifestation of Primary Squamous Cell Cancer of the Thyroid Gland

Paraneoplastic manifestation (PNM) of cancers is a non-metastatic, non-invasive systemic effect of malignancies due to chemokines and hormones produced by the primary neoplasm. Squamous cell cancers (SCCs) are known to present with PNM. Primary SCC of thyroid accounts for <1% of all thyroid malignancies and carries a very poor prognosis. We present a rare case of SCC arising from the thyroid gland who presented with fever, leukemoid reaction and hypercalcemia as part of PNM. A 67-year-old male patient presented with two months history of intermittent high-grade fever, weakness, loss of weight and appetite. Examination revealed a large (~10 cm) hard swelling over the right side of the neck. Investigations revealed neutrophilic leukocytosis, elevated C-reactive protein (CRP) and procalcitonin and hypercalcemia with a normal thyroid-stimulating hormone (TSH). The fever workup was negative for infection. Fine-needle aspiration cytology (FNAC) and core biopsy of the thyroid mass revealed malignant cells with squamous differentiation. An extensive search for possible other primary was ruled out by triple endoscopy. The combination of fever, neutrophilic leukocytosis, hypercalcemia and squamous malignancy was consistent with a diagnosis of PNM of SCC. A fluorodeoxyglucose-positron emission tomography (FDG-PET) CT scan showed a heterogeneously enhancing mass lesion in the right lobe of the thyroid with some retrosternal extension. He underwent total thyroidectomy with bilateral central compartment neck dissection. Final histopathology revealed moderately differentiated SCC of the thyroid. Concurrent chemoradiation was given. Despite continued chemotherapy, he succumbed to illness within six months of diagnosis. Primary SCC of thyroid (PSCCT) is a rare malignancy. It is a highly aggressive tumor having a poor prognosis with a median survival time of about 9-12 months and less clearly defined therapy due to its rarity. Paraneoplastic manifestation of PSCCT is known. As fever, leukemoid reaction and hypercalcemia can be a paraneoplastic manifestation, one should think of PSCCT.

Therapeutic Effect of Combined Dabrafenib and Trametinib Treatment of BRAF V600E-Mutated Primary Squamous Cell Carcinoma of the Thyroid: A Case Report

INTRODUCTION

Primary squamous cell carcinoma (PSCC) of the thyroid is an exceptionally rare malignancy accounting for <1% of all primary thyroid cancers. Therapy is multimodal including surgery, radiotherapy, and chemotherapy but with no consensus for management and therapy. Here, we describe a case of a male patient who presented with a BRAF V600E-mutated PSCC of the thyroid gland showing response to combined dabrafenib and trametinib therapy over a period of >12 months.

CASE PRESENTATION

A 78-year-old male patient presented with a 3-week history of dysphonia and dyspnoea. Laryngoscopy revealed a mechanical obstruction by a right-sided, subglottical mass, which on cervical ultrasound was highly suggestive of anaplastic thyroid carcinoma. Additional workup including esophagogastroduodenoscopy showed compression of the oesophagus but no oesophageal infiltration by the tumour. Immunohistochemistry displayed CK19-positive cells indicating epithelial origin of the tumour. CK5/6 and P40 immunohistochemistry confirmed the morphological impression of squamous cell differentiation while staining with thyroid markers TTF-1 and TPO was negative and PAX8 showed a nuclear positive signal. Based on immunohistopathology, presence of TP53 and BRAF V600E mutations, and exclusion of metastatic squamous cell carcinoma of other origin, the diagnosis of a PSCC of the thyroid was established. As an individualized treatment concept, we decided to advocate combined BRAF V600E targeting by the multikinase inhibitors dabrafenib and trametinib. This led to drastic improvement in patient's quality of life without severe side effects over a period of >12 months.

CONCLUSION

In this case, molecular diagnosis allowed a highly individualized treatment concept with combined dabrafenib and trametinib therapy.

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.

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.

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.

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.