Surgical Pathology Criteria

Adenocarcinoma of the Colon and Rectum

Differential Diagnosis

Metastatic adenocarcinoma of unknown type

CK7 and CK20 expression in carcinomas

CK7+20+ CK7-20+
Ovary mucinous 90% Colorectal adeno 80%
Transitional cell 65% Merkel cell 70%
Pancreas adeno 65% Gastric adeno 35%
Cholangio 65%  
Gastric adeno 40%  
Excluded tumors 5% or less Carcinoid; Germ cell; Esoph squam; Head/neck squam; Hepato-cellular; Lung small cell & squam; Ovary non-mucinous; Renal adeno Excluded tumors 5% or less Breast; Carcinoid lung; Cholangio; Esoph squam; Germ cell; Lung all types; Hepato-cellular; Ovary; Pancreas adeno; Renal adeno; Transitional cell; Uterus endometrioid
CK7+20- CK7-20-
Ovary non-mucinous 100% Adrenal 100%
Thyroid (all 3 types) 100% Seminoma & Yolk Sac 95%
Breast 90% Prostate 85%
Lung adeno 90% Hepatocellular 80%
Uterus endometrioid 85% Renal adeno 80%
Embryonal 80% Carcinoid intestinal & lung 80%
Mesothelioma 65% Lung small cell & squam 75%
Transitional cell 35% Esoph squam 70%
Pancreas adeno 30% Head/neck squam 70%
Cholangio 30% Mesothelioma 35%
Excluded tumors 5% or less Colorectal adeno; Ovary mucinous; Yolk Sac; Seminoma Excluded tumors 5% or less Breast; Cholangio; Lung adeno; Ovary; Pancreas adeno
  • Derived from Chu PG, Weiss LM. Histopathology 2002, 40:403-439 and other sources
  •  

    Adenocarcinoma Type CDX2 Staining
    Colorectal 70-98%
    Small intestine 60%
    Stomach 60-70%
    Endocervix 30%
    Ovary primary mucinous 40-70%
    Uterus 10-15%
    Bile duct 13-25%
    Lung 0-12%
    Pancreas 0-32%
    Liver 0%
    Breast 0%

     

    Colorectal Adenoma Containing Invasive Adenocarcinoma Colorectal Adenoma with Benign Misplacement of Glands / Pseudoinvasion
    Usually significant architectural and/or cytologic atypia Usually lacks significant architectural and/or cytologic atypia (high grade dysplasia may be misplaced occasionally but is typically accompanied by bland adenoma tissue)
    Desmoplastic stroma Inflammatory or fibrotic stroma
    Infiltrates through muscularis mucosae Frequently demonstrable continuity with surface through a gap in the muscularis mucosae
    Hemosiderin restricted to head of polyp Hemosiderin common in stalk stroma
    Glands not accompanied by lamina propria Glands may be accompanied by lamina propria
    Usually infiltrative, non-circumscribed Frequently circumscribed
    May occur throughout the colorectum Virtually restricted to left colon
    Collagen type IV weak, discontinuous Collagen type IV strong, continuous around epithelial nests
    E cadherin markedly decreased staining compared to overlying adenoma E cadherin same intensity as overlying adenoma (high grade dysplasia may show decrease)

     

    Mucosal Prolapse / Cloacogenic Polyp (Localized Colitis Cystica Profunda) Invasive Colorectal Adenocarcinoma
    No surface carcinoma component Surface component usually present
    No high grade nuclear atypia High grade nuclear atypia usually present
    No cribriform glands or complex architecture Complex architecture with cribriform glands frequent
    No desmoplastic stromal response Desmoplastic stromal response
    Lamina propria may accompany displaced glands No lamina propria accompanying invasive glands
    Mean age 35 years Occurs in older patients

     

    Colorectal Medullary Carcinoma Colorectal Poorly Differentiated Carcinoma NOS
    Lacks any gland formation At least 5% gland formation
    Uniform small to medium sized nuclei Pleomorphic large nuclei
    Uniformly prominent nucleoli Variable nucleoli
    Pushing border Infiltrative border
    Prominent lymphoid infiltrate in virtually all cases Lymphoid infiltrate variable

     

    Colorectal Medullary Carcinoma Colorectal Undifferentiated Carcinoma NOS
    Lacks any gland formation May have <5% gland formation
    Uniform small to medium sized nuclei Pleomorphic large nuclei
    Uniformly prominent nucleoli Variable nucleoli
    Pushing border Infiltrative border
    Prominent lymphoid infiltrate in virtually all cases Lymphoid infiltrate variable

    Stanford Medicine Resources:

    Footer Links: