Table 3.
Summary of folliculin (FLCN) and glycoprotein non-metastic B (GPNMB) immunostaining in Birt–Hogg–Dubé (BHD) and sporadic renal tumors
| Immunostaining | HOCT/oncocytoma | Chromophobe | Papillary | Clear cell | ||||
|---|---|---|---|---|---|---|---|---|
| BHD, n = 6 (%) | Sporadic, n = 8 (%) | BHD, n = 9 (%) | Sporadic, n = 18 (%) | BHD, n = 2 (%) | Sporadic, n = 11 (%) | BHD, n = 2 (%) | Sporadic, n = 20 (%) | |
| FLCN | ||||||||
| Nuclear | 0 (0) | 6 (75) | 2 (22) | 11 (61) | 0 (0) | 9 (82) | 0 (0) | 16 (80) |
| Cytoplasmic | 5 (83) | 2 (25) | 7 (78) | 6 (33) | 1 (50) | 0 (0) | 0 (0) | 1 (5) |
| Negative | 1 (17) | 0 (0) | 0 (0) | 1 (6) | 1 (50) | 2 (18) | 2 (100) | 3 (15) |
| GPNMB | ||||||||
| (−) | 0 (0) | 8 (100) | 0 (0) | 9 (50) | 1 (50) | 10 (91) | 2 (100) | 20 (100) |
| (+) | 1 (17) | 0 (0) | 2 (22) | 8 (44) | 0 (0) | 1 (9) | 0 (0) | 0 (0) |
| (++) | 5 (83) | 0 (0) | 7 (78) | 1 (6) | 1 (50) | 0 (0) | 0 (0) | 0 (0) |
(−), No staining or <5% of the tumor cells positive; (+), occasional weak staining; (++), moderate or intense staining. HOCT, hybrid oncocytic chromophobe tumor.