Combined Immunohistochemistry for the “Three 7” Markers (CK7, CD117, and Claudin-7) Is Useful in the Diagnosis of Chromophobe Renal Cell Carcinoma and for the Exclusion of Mimics: Diagnostic Experience from a Single Institution
Table 1
Immunohistochemistry results of the “three 7” markers in CHRCC, CCRCC, PRCC, and OC.
Markers
Results
CHRCC (%)
CCRCC (%)
PRCC (%)
OC (%)
CK7
+
64 (94)
16 (8)
15 (47)
2 (7)
−
4 (6)
183 (92)
17 (53)
28 (93)
CD117
+
59 (87)
1 (0.5)
5 (16)
25 (83)
−
9 (13)
198 (99.5)
27 (84)
5 (17)
Claudin-7
+
64 (94)
24 (12)
12 (38)
8 (27)
−
4 (6)
175 (88)
20 (62)
22 (73)
CK7+CD117
+
54 (79)
0 (0)
4 (13)
1 (3)
−
14 (21)
199 (100)
28 (87)
29 (97)
CK7+Claudin-7
+
60 (88)
3 (1.5)
9 (28)
0 (0)
−
8 (12)
196 (98.5)
23 (72)
30 (100)
CD117+Claudin-7
+
56 (82)
0 (0)
0 (0)
5 (17)
−
12 (18)
199 (100)
32 (100)
25 (83)
CK7+CD117+Claudin-7
+
52 (76)
0 (0)
0 (0)
0 (0)
−
16 (24)
199 (100)
32 (100)
30 (100)
Defined as negative when one of any marker was not positive.