Colorectal Cancer Metastasis to the Thymus Gland: Rare Presentation of Colorectal Cancer as Anterior Mediastinal Mass

Table 1

Morphology and immunophenotype of the resected colonic and mediastinal adenocarcinomas.

Features	Colonic adenocarcinoma	Anterior mediastinal adenocarcinoma
Morphology
Precursor lesion	Yes	No
Differentiation	Poor	Poor
Micropapillary feature	Present	Present
Lymphovascular invasions	Extensive	Extensive
Lymph node metastasis	Present	Present
Immunophenotype
CDX2	Diffuse and strong immunoreactivity	Diffuse and strong immunoreactivity
CK20	Diffuse and strong immunoreactivity	Diffuse and strong immunoreactivity
CK7	Positive	Positive
β-catenin	Cytoplasmic and nuclear staining	Cytoplasmic and nuclear staining
TTF-1	N/A	Negative
PAX 8	N/A	Negative
cKIT	N/A	Negative
SALL4	N/A	Negative
Microsatellite status
Microsatellite stable	Yes	Yes

N/A: not performed.