areola (n.), areolar (adj.)

https://doi.org/10.1351/goldbook.10426
  1. A circular area of different color surrounding a central point, such as that surrounding the nipple of the breast, the part of the iris surrounding the pupil of the eye, or an area surrounding a vesicle.
  2. Any minute space or interstice in a tissue.
Source:
PAC, 2016, 88, 713. (Glossary of terms used in developmental and reproductive toxicology (IUPAC Recommendations 2016)) on page 726 [Terms] [Paper]