Colon
Carcinoma
Adenosquamous carcinoma
Author: Raul S. Gonzalez, M.D.
Last author update: 14 April 2021
Last staff update: 16 January 2025 (update in progress)
Copyright: 2002-2025, PathologyOutlines.com, Inc.
PubMed Search: Adenosquamous carcinoma [title] colon
Table of Contents
Definition / general | Essential features | Sites | Pathophysiology | Clinical features | Case reports | Treatment | Clinical images | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Sample pathology report | Differential diagnosis | Additional references | Board review style question #1 | Board review style answer #1Cite this page: Gonzalez RS. Adenosquamous carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colontumoradenosquamous.html. Accessed January 17th, 2025.
Definition / general
- Rare (0.1% of colonic carcinomas) WHO recognized epithelial malignancy of colon with glandular and squamous elements (Am J Surg Pathol 1978;2:47)
Essential features
- Rare primary subtype of colorectal carcinoma
- Has higher metastatic rate and worse prognosis than conventional colorectal adenocarcinoma (Dis Colon Rectum 2012;55:509, Dis Colon Rectum 1999;42:258)
Sites
- Typically arises in right colon (Dis Colon Rectum 2001;44:341)
Pathophysiology
- HPV infection does not appear to play a role (Surg Today 2009;39:619, Eur J Surg Oncol 2002;28:657)
Clinical features
- Tumor stage is often advanced at presentation (Dis Colon Rectum 1996;39:1265)
- May cause paraneoplastic hypercalcemia (Int J Clin Oncol 2005;10:144, Am Surg 2001;67:585)
- Can occur in patients with ulcerative colitis (Dis Colon Rectum 1988;31:323)
Case reports
- 71 year old man with adenosquamous carcinoma of sigmoid colon (Int J Clin Exp Med 2013;6:390)
- 78 year old woman with associated paraneoplastic hypercalcemia (Int J Clin Oncol 2005;10:144)
- Adenosquamous carcinoma of colon (Am Surg 2006;72:754)
- Adenosquamous carcinoma of colorectum (J Exp Clin Cancer Res 2001;20:293)
Treatment
- Surgery with adjuvant treatment
Clinical images
Images hosted on other servers:
Circumferential obstructive mass
Bleeding circumferential lobulated mass
Gross images
Images hosted on other servers:
Cross section
Microscopic (histologic) description
- Resembles conventional colorectal adenocarcinoma but with areas of squamous differentiation, either admixed or distinct
Microscopic (histologic) images
Contributed by Raul S. Gonzalez, M.D.
Adenosquamous carcinoma
Images hosted on other servers:
Collision-like areas
Composite-like areas
Adenosquamous carcinoma
Malignant squamous cells with keratinization
Positive stains
Sample pathology report
- Ascending colon, biopsy:
- Adenosquamous carcinoma (see comment)
- Comment: The malignancy demonstrates both glandular elements and squamous elements. The former is positive for CDX2 by immunohistochemistry and the latter is positive for p40 by immunohistochemistry.
Differential diagnosis
- Squamous cell carcinoma:
- Also rare
- No glandular elements
Additional references
Board review style question #1
Which of the following is true about adenosquamous carcinoma of the colon?
- Always arises in the setting of HPV infection
- Has a good prognosis
- Often presents at an advanced stage
- Represents approximately 10% of colorectal carcinomas
Board review style answer #1
