Case 102 - Discussion

Uploaded: 2007-09-27, Updated: 2007-10-03

 

 

CK7 CK7
CK7 CK5/6
CD56 CD56

MIXED SMALL CELL AND SQUAMOUS CELL CARCINOMA

The tumor has two distinct and separate morphologic features combined  in the mass.  The small cell component is CD56 positive and consists of nests, bundles and cords of cells with scant cytoplasm, pleomorphic nuclei and necrosis.  The pattern is typical of small cell carcinoma.  Intermixed with this tumor are nests of well differentiated squamous cell carcinoma.  The epithelial component is CK5/6 positive and CK7 positive.  CK5/6 is negative in the small cell component and CK7has variable expression throughout the tumor and adjacent normal tissue. This tumor is best classified as a mixed squamous cell and small cell carcinoma and not a small cell variant of squamous cell carcinoma.