Colon
Carcinoma
Micropapillary carcinoma
Author: Raul S. Gonzalez, M.D.
Last author update: 1 February 2021
Last staff update: 16 January 2025 (update in progress)
Copyright: 2002-2025, PathologyOutlines.com, Inc.
PubMed Search: Micropapillary carcinoma [title] colon
Table of Contents
Definition / general | Essential features | Epidemiology | Pathophysiology | Case reports | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Molecular / cytogenetics description | Sample pathology report | Differential diagnosis | Board review style question #1 | Board review style answer #1Cite this page: Gonzalez RS. Micropapillary carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/colontumormicropapillary.html. Accessed April 1st, 2025.
Definition / general
- Uncommon subtype of colonic adenocarcinoma with distinctive behavior
- Officially recognized in WHO classification
Essential features
- Histology: small clusters of malignant cells with abundant eosinophilic cytoplasm and pleomorphic nuclei
- High rate of lymph node metastasis (even when early stage) and poor prognosis
Epidemiology
- Micropapillary features may be present in 9% to 19% of colorectal carcinomas (Hum Pathol 2006;37:809, Mod Pathol 2007;20:729)
Pathophysiology
- Lymph node metastasis are very common, even in pT1 / pT2 tumors (Am J Surg Pathol 2009;33:1287)
- Prognosis worse than for conventional colorectal carcinoma (Colorectal Dis 2012;14:e567)
Case reports
- 72 year old woman with invasive micropapillary carcinoma of sigmoid colon (Int J Clin Exp Pathol 2008;1:457)
Microscopic (histologic) description
- Small clusters of malignant cells with abundant eosinophilic cytoplasm and pleomorphic nuclei
- Micropapillae inhabit lacunar-like spaces and demonstrate a reverse polarity configuration, with apical surfaces facing the periphery rather than the center
- Lymphovascular invasion is commonly present
- Morphology is similar to micropapillary carcinomas of other organs (Adv Anat Pathol 2004;11:297)
- Coexisting regions of conventional adenocarcinoma also usually present
Microscopic (histologic) images
Contributed by Raul S. Gonzalez, M.D.
Micropapillary carcinoma
Positive stains
- MUC1 (inside out staining pattern) (Histopathology 2005;47:479)
- SOX2, NOTCH3 (stem cell markers) (Mod Pathol 2013;26:1123)
Molecular / cytogenetics description
- Increased rate of TP53 alterations and lower rate of microsatellite instability (Mod Pathol 2011;24:729)
Sample pathology report
- Ascending colon, mass, biopsy:
- Carcinoma with prominent micropapillary features (see comment)
- Comment: Micropapillary carcinoma of the colon has a reported propensity to metastasize to lymph nodes even when early stage.
Differential diagnosis
- Tumor budding:
- Does not show reverse polarity (Histopathology 2002;40:127)
Board review style question #1
Which of the following is true about micropapillary carcinoma of the colon?
- It is characterized by high microsatellite instability
- It metastasizes to lymph nodes often
- It represents < 1% of colon cancers
- Micropapillae are the same thing as tumor budding
Board review style answer #1
