Thyroid gland
Other carcinoma
Squamous cell carcinoma

Author: Shuanzeng Wei, M.D., Ph.D. (see Authors page)
Editor: Zubair W. Baloch, M.D., Ph.D.

Revised: 17 February 2017, last major update September 2016

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: squamous cell carcinoma thyroid

Cite this page: Squamous cell carcinoma. PathologyOutlines.com website. http://pathologyoutlines.com/topic/thyroidSCC.html. Accessed December 14th, 2017.
Definition / general
  • Very rare, highly lethal thyroid carcinoma with pure squamous component
  • Clinically and pathologically shares features with anaplastic thyroid cancers; can be regarded as a variant of anaplastic thyroid carcinoma
  • Must rule out:
    • Metastasis or direct invasion of squamous cell carcinoma from oropharynx, larynx, trachea, lung, other organs
    • Papillary carcinoma with foci of squamous differentiation (occurs in 15 to 45% of papillary carcinomas)
    • Anaplastic thyroid carcinoma with squamous differentiation
    • Other thyroid carcinomas with squamous differentiation, including mucoepidermoid carcinoma, sclerosing mucoepidermoid carcinoma with eosinophilia, CASTLE
Essential features
  • Squamous cell carcinoma is regarded as a variant of anaplastic thyroid carcinoma
  • Aggressive clinical behavior
Epidemiology
  • Similar to anaplastic carcinoma, affects older patients with chronic goiter
Clinical features
  • Older patients present with a rapidly enlarging neck mass
  • Patients may have a long history of preexisting thyroid disease
  • Extrathyroidal extension and cervical nodal metastases are common, distant metastases are rare
Prognostic factors
  • Poor prognosis with median survival < 6 months
  • Death in almost all cases, usually due to local progression (Int Semin Surg Oncol 2007;4:8) or airway compression
Case reports
Treatment
  • Radical resection and radiation (often radioresistant)
Clinical images

Images hosted on other servers:

Ulceroproliferative growth

Recurrent ulceroproliferative growth

Mass pressuring and
infiltrating trachea and
surrounding soft tissue

Gross description
  • Firm infiltrating mass with necrosis
Gross images

Images hosted on other servers:

Enlarged left lobe

White tumor with central necrosis

Microscopic (histologic) description
  • Invasive squamous carcinoma, with or without keratinization
  • High mitotic index
  • Extrathyroid, vascular and perineural invasions are common
Microscopic (histologic) images

Images hosted on PathOut servers:

Squamous cell carcinoma with necrosis, contributed by Shuanzeng Wei, M.D., Ph.D.



Images hosted on other servers:

Infiltrating squamous cell carcinoma

Cytology images

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Atypical squamoid cell

Positive stains
Differential diagnosis
  • CASTLE: circumscribed, slowly growing tumor, CD5+, CD117+
  • Metastasis or direct invasion of squamous cell carcinoma from other organs: history of squamous cell carcinoma, PAX8-
  • Papillary thyroid carcinoma with squamous differentiation: squamous component is small portion of the well differentiated thyroid carcinoma
  • Squamous metaplasia: benign squamous cells