Diagnostic utility of cytokeratin 17 immunostaining in morpheaform basal cell carcinoma and for facilitating the detection of tumor cells at the surgical margins.
BACKGROUND
The morpheaform subtype of basal cell carcinoma (BCC) often presents a diagnostic histological challenge, and its true margin may be difficult to determine with accuracy. This tumor may also be difficult to distinguish from other adnexal neoplasms having a benign clinical course. Previous work has shown that cytokeratin 17 (CK17 or K17) expression is high in BCC.


OBJECTIVE
To confirm the expression of K17 across the subtypes of superficial, nodular and morpheaform BCC variants and to compare K17 expression in each of these subtypes of BCC with that in two other adnexal neoplasms.


METHODS
Tissue specimens from each tumor category were randomly collected, immunolabeled, and scored for K17 expression according to intensity and extent of immunostaining.


RESULTS
Our results indicate that K17 is a useful marker in the identification and outlining of BCC. Moreover, in morpheaform BCC, K17 immunostaining clearly detected individual tumor cells well away from the dermal tumor strands that otherwise seemed nonmalignant according to hematoxylin and eosin staining alone. In addition, the expression of K17 in morpheaform BCC is capable (100% of specimens; p < .001) of distinguishing this tumor from desmoplastic trichoepithelioma.


CONCLUSIONS
We propose that K17 immunostaining could improve the diagnostic and surgical management of these tumors.
Department of Dermatology and Skin Cancer, Roger Williams Medical Center, Providence, Rhode Island 02908, USA.
Heidi
H
Anderson-Dockter
Todd
T
Clark
Satori
S
Iwamoto
Ming
M
Lu
David
D
Fiore
Jane K
JK
Falanga
Vincent
V
Falanga
D014408:Biomarkers, Tumor / Q000032:analysis; D002280:Basal Cell Carcinoma / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D053537:Keratin-17 / Q000378:metabolism*; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000378:metabolism
D014408:Biomarkers, Tumor; D053537:Keratin-17