Immunohistochemical stains were positive for cytokeratin-20 (CK-20), chromogranin A (Figure 4) and synaptophysin and negative for CD45, CD20, and cytokeratin-7 (CK-7).
CK-20 is a highly sensitive marker for MCC, staining positively in a paranuclear, dot-like pattern in 89% to 100% of tumors .
Immunohistochemical staining of liver tissue was positive for CK-7, p63 and p40 and negative for TTF-1, CK-20
and CDX-2, confirming SCC of lung as primary malignancy (Figure 6).
Results of immunohistochemical staining Immunostain Result Bcl2 Negative c-erbB2 Negative (1+) Cyclin D1 Positive EGFR Positive (2+) Ki-67 60% P53 Positive AMACR Negative CK-7 Negative CK-20
Positive CDX-2 Positive TTF-1 Negative
reported that the detection of circulating cytokeratin 20 (CK-20)-positive cells by reverse transcription (RT)-PCR in 33.8% of patients with PDAC was associated with shorter OS (19).
 Nonstandard abbreviations: PDAC, pancreaticductal adenocarcinoma; CA19-9,carbohydrate antigen 19-9; CTC, circulating tumor cell; PFS, progression-free survival; OS, overall survival; CTM, circulating tumor microemboli; SLB, supported lipid bilayer; EpCAM, epithelial cell adhesion molecule; DAPI, 4',6-diamidino-2-phenylindole; RECIST, response evaluation criteria insolid tumors; CEA, carcinoembryonic antigen; DM, diabetes mellitus; CK-20, cytokeratin 20; RT, reverse transcription; qPCR, quantitative PCR.
primary Low-grade FDG uptake in right axillary nodes No metabolically active lesion seen to suggest a possible primary neoplasm Minimal free fluid seen in POD Repeat bone marrow Neoplastic cells express CK-7, GCDFP-15, biopsy with IHC ER, PR, CK 19 Negative to CK-20
, CDX-2, CEA, mammoglobin, TTF-1, CA-125, CA-19-9 Impression: metastatic carcinoma, consistent with primary site in breast Gastro duodenoscopy Fundic gastritis Duodenal lesion as above GIST???
The epithelial component showed variable positivity, in different areas, for cytokeratin (CK)-7 and CK-20
. There was no cytological atypia nor any features of malignancy in either the epithelial or spindle cell elements.
Section of ovary with positive CK-20
Kato and associates presented a case of CK-20
positive large cell neuroendocrine carcinoma suggesting a link between colonic adenocarcinoma and large cell neuroendocrine carcinomas as CK-20
is normally associated with colonic adenocarcinoma.
5c: A right lung biopsy negative for CK-20
. [Figure omitted]