Skin - Nonmelanocytic tumors
Carcinoma (non-adnexal)
Adenosquamous carcinoma

Author: Ghassan Tranesh, M.D. (see Authors page)
Editor (personal): Hong Qu, M.D.
Editorial Board review: Sara C. Shalin, M.D., Ph.D.

Revised: 13 October 2016, last major update January 2015

Copyright: (c) 2002-2016,, Inc.

PubMed Search: Adenosquamous carcinoma [title] skin

Cite this page: Adenosquamous carcinoma. website. Accessed July 18th, 2018.
Definition / general
  • Frequent confusion in the literature regarding this entity in the head and neck and high grade mucoepidermoid carcinoma (Int J Clin Exp Pathol 2014;7:1809)
  • More common in organs where adenocarcinoma arises frequently, including stomach, intestines and uterus (Oncol Lett 2014;7:1941)
Pathophysiology / etiology
  • Although its pathogenesis is largely unknown, 4 hypotheses have been proposed:
    1. Malignant transformation of both squamous and glandular-like cells originating from pleiotropic epithelial stem cells
    2. Tumorigenesis of squamous metaplasia in columnar epithelium
    3. Transdifferentiation of adenocarcinoma to squamous cell carcinoma
    4. Coexistence of both carcinomas (World J Surg Oncol 2013;11:124)
  • Neoplasm composed of an admixture or separate areas of squamous cell carcinoma and adenocarcinoma
  • Criteria for squamous cell carcinoma component are 2 or more of these features:
    • Intercellular bridging
    • Keratin pearl formation
    • Parakeratotic differentiation
    • Individual cell keratinization
    • Cellular arrangement showing a pavementing or mosaic pattern
  • Criterion for adenocarcinoma component is demonstration of intracytoplasmic mucin
  • World Health Organization Classification does not require intracytoplasmic mucin for diagnosis of adenocarcinoma in the presence of true glandular formation (Int J Clin Exp Pathol 2014;7:1809)
Case reports
  • Surgical excision or Mohs microsurgery are common treatment options (Head Neck Pathol 2011;5:108)
  • Locoregional recurrence is not uncommon
Clinical images

Images hosted on other servers:

Fig 3: recurrent tumor of shoulder

Various images

Gross description
  • White nodular infiltrate into subcutaneous tissue
Microscopic (histologic) description
  • Infiltrative islands of squamous cell carcinoma with admixed mucin-containing glandular structures, adenomatous changes and acinar formation
  • Glandular structures lined by low columnar epithelium, sometimes lined by an eosinophilic cuticle (ductular differentiation)
  • Perineural invasion relatively common (Arch Dermatol 2009;145:1152)
Microscopic (histologic) images

Images hosted on other servers:

Fig 1: Infiltrative nests and keratinizing
cysts are admixed with glandular elements

Fig 2: CK903 (high molecular weight keratin)
stains the tumor, CEA highlights glandular differentiation

Positive stains
Differential diagnosis