Cytokeratin 7 and 20 expression in
Scott D. Humble, Victor G. Prieto
and Marcelo G. Horenstein
Departments of Pathology, University of South
Alabama Medical Center, Mobile, Alabama,
and University of Texas MD Anderson Cancer
Center, Houston, Texas
Marcelo G. Horenstein MD, Director of
Dermatopathology, University of South Alabama,
2451 Fillingim St, Mobile, AL 36617, USA
Accepted October 3, 2002
Background: Epithelioid sarcoma (ES) is a rare malignant soft tissue
tumor of uncertain histogenesis that arises predominantly in the
extremities of young adults. Immunohistochemically, the neoplastic
cells are typically positive for vimentin, low molecular weight
cytokeratin (CAM5.2) and epithelial membrane antigen (EMA).
Method: We examined eight cases of ES from seven different
patients. All cases were studied with immunohistochemistry for EMA,
CAM5.2 (keratin 8 and 18), 34BE12 (keratins 1, 5, 10 and 14/15),
cytokeratins 7 and 20 (CK7, CK20), and CD34.
Results: The average patient age was 53 (range 43–76) and the
male:female ratio was 5:2. The location was the upper extremity in
five tumors, the lower extremity, the perineum, and the paraspinal soft
tissue in one tumor each. All cases contained predominantly
epithelioid cells, but spindle cells were also present in three cases. All
cases contained areas of geographic necrosis. CAM5.2 was strongly
positive in seven tumors and focally positive in one (8/8). EMA was
diffusely positive in two cases and focally positive in five cases (7/8).
CD34 was diffusely positive in 3/8 cases. 34BE12 was diffusely
positive in one case and focally positive in two others (3/8). CK7 was
diffusely positive in one case and focally positive in another (2/8).
CK20 was negative in all cases (0/8). All cases tested were positive for
vimentin (6/6), 2 cases were focally positive for HHF35 (2/5), and all
cases tested were negative for S-100 protein (0/7).
Conclusions: In addition to the known immunoreactivity for
CAM5.2 and EMA, there is positivity for CK7 and 34BE12 in a small
proportion of cases. None of the cases expressed CK20. This
immunophenotypic profile suggests that ES is more similar to
carcinoma and synovial sarcoma than to other soft tissue tumors, and
may be of diagnostic utility.
Humble SD, Prieto VG, Horenstein MG. Cytokeratin 7 and 20 expression
in epithelioid sarcoma.
J Cutan Pathol 2003; 30: 242–246. # Blackwell Munksgaard 2003.
Epitheliod sarcoma (ES) is a rare, malignant soft tissue
tumor that typically arises in the extremities of young
adults. Although the tumor initially behaves indo-
lently, local recurrences and distant metastases are
frequent.1The histogenesis of ES has been the subject
of controversy. A mesenchymal origin was favored
initially due to association with tendons and fascial
structures, as well as the deep origin of some tumors
within the soft tissue.1Fibroblasts and fixed tissue
histiocytes have been considered as probable progeni-
tor cells; however, a synovioblastic origin has also
been proposed.2,3Ultrastructurally, ES has been
origin.2–4The differential diagnosis of ES is extensive,
as the tumor can be misinterpreted pathologically as
J Cutan Pathol 2003: 30: 242–246
Blackwell Munksgaard. Printed in Denmark
Copyright # Blackwell Munksgaard 2003