| UB | ultimobranchial body; Unna boot; upper back; urinary bladder |
|---|---|
| UT | total unsharpness; Ullrich-Turner [syndrome]; Unna-Thost [syndrome]; untested; untreated; urinary tr... |
| BCN | basal cell nevus; bilateral cortical necrosis |
| BCNS | basal cell nevus syndrome |
| B-K | initials of two patients after whom a multiple cutaneous nevus [mole] was named |