External ear tumors - malignant
Squamous cell carcinoma

Author: Nat Pernick, M.D. (see Authors page)

Revised: 16 February 2018, last major update October 2013

Copyright: (c) 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: Squamous cell carcinoma [title] external auditory canal

Related Topics: Adenoid squamous carcinoma of external auditory canal, Spindle cell carcinoma of external auditory canal

Cite this page: Pernick, N. Squamous cell carcinoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/earsccexternal.html. Accessed October 17th, 2018.
Definition / general
  • 15% of primary cutaneous carcinomas of external ear and auditory canal
  • Usually age 60+ years
  • Poor prognostic factors: > 2 cm, depth > 4 mm, poorly differentiated tumors, perineural invasion, development within a scar, previously treated squamous cell carcinoma at the site, immunosuppression, location within inner portion of canal with deep involvement of temporal bone
  • Tumor spread: tumors of helix spread along helix, to antihelix, to posterior surface of ear; tumors of antihelix spread concentrically; tumors of posterior surface spread to helix; tumors of canal tend to invade bone, may destroy tympanic membrane and penetrate middle ear
Case reports
  • 65 year old woman with pigmented squamous cell carcinoma with dendritic melanocyte colonization in the external auditory canal (Pathol Int 1999;49:909)
  • 69 year old man with bilateral squamous cell carcinoma of the external auditory canals (Laryngoscope 2002;112:1003)
  • 72 year old man with bilateral auditory canal squamous cell carcinoma (HNO 2006;54:41)
  • 89 year old man with angiolymphoid hyperplasia with eosinophilia associated to a squamous cell carcinoma of the ear (Dermatol Surg 2004;30:1367)
  • Squamous cell carcinoma in situ of external auditory canal (J Laryngol Otol 2006;120:684)
  • Complete excision (mastoidectomy or temporal bone resection for canal tumors), possibly radiation therapy
  • Tumors of external ear have low recurrence rate (Dermatol Surg 2005;31:1423)
  • Canal tumors often recur (19%) or metastasize (11%); death may occur due to intracranial extension
Gross description
  • Polypoid, firm / rubbery nodules, frequent ulceration
Microscopic (histologic) description
  • Well differentiated: most common, composed of infiltrating nests of cells with keratin pearls or individual cell keratinization and intercellular bridges; variable nuclear atypia; frequent mitotic activity with atypical forms; invasion may be superficial with irregular budding of basal epithelium or irregular tongues of tumor projecting downward
  • Moderated differentiated: scattered individually keratinized cells but no keratin pearls
  • Poorly differentiated: no obvious keratinization, but squamous epithelial dysplasia, pavement like cellular pattern, foci with intercellular bridges
Microscopic (histologic) images

Images hosted on PathOut server:
Contributed by Dr. Semir Vranic:
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Angiolymphatic invasion

Images hosted on other servers:
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Various images

Additional references