Colon tumor
Lymphoepithelioma-like carcinoma

Author: Raul Gonzalez M.D. (see Authors page)

Revised: 25 November 2015, last major update November 2015

Copyright: (c) 2002-2015,, Inc.

PubMed Search: Lymphoepithelioma-like carcinoma [title] colon
Definition / General
  • Extremely rare subtype of colonic adenocarcinoma (<10 reported cases) associated with Epstein-Barr virus infection
  • Only case reports exist, though some may actually be medullary carcinoma (see differential diagnosis section)
Essential features
  • May also be called "poorly differentiated adenocarcinoma with lymphoid stroma"
Clinical Features
  • No particular age, sex or site predilection
Case Reports
Clinical Images
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Colonoscopy findings

Micro Description
  • Syncytial growth pattern of undifferentiated pleomorphic malignant epithelial cells with ill defined borders, prominent nucleoli and brisk mitotic activity
  • Prominent stromal and intratumoral lymphoid infiltrate
  • Focal necrosis
  • Infiltrative margins
Micro Images
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Lymphoid follicle formation

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Polypoid nature

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Cords and clusters

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Pleomorphic with large nuclei

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Bladder tumor

Positive Stains
  • EBV / EBER positivity in tumor cells reported in some but not all cases
    • Other times, only surrounding lymphocytes are positive
  • Cytokeratin AE1/AE3
Negative Stains
  • Neuroendocrine markers, S100
Differential Diagnosis
  • Medullary carcinoma: lymphocytic infiltrates are more prominent peritumorally than intratumorally; pushing, not infiltrative, margins; distinction not always perfect on H&E
  • In the stomach, "medullary gastric cancer" should be used for mismatch repair deficient tumors and "lymphoepithelioma-like gastric cancer" should be used for EBER+ cases
    • Such a distinction may carry over to the colon, but the morphologic overlap and rarity of EBV+ colon cancers makes this difficult to determine