The effects of the levonorgestrel intrauterine system (Mirena coil) on endometrial morphology.
OBJECTIVE
The Mirena coil is a levonorgestrel releasing intrauterine device that is in widespread use. This study aims to document the endometrial morphology associated with this device.


METHODS
Endometrial specimens from 75 women with the Mirena coil were reviewed and the histological features detailed.


RESULTS
Morphological features found in most of the endometria were decidualisation of stroma (72 of 75 cases), atrophy of endometrial glands (65 of 75 cases), a surface papillary pattern (38 of 75 cases), and a stromal inflammatory cell infiltrate (59 of 75 cases). Additional common histological features were the presence of foci of stromal myxoid change (29 of 75 cases) and stromal haemosiderin pigment (24 of 75 cases). Reactive atypia of surface glands, glandular metaplastic changes, stromal necrosis, and stromal calcifications were found in small numbers of cases.


CONCLUSIONS
The endometrial features are characteristic and relatively constant and are in keeping with the effects of both a progestogenic compound and a mechanical device. Pathologists should be aware of these histological features because the Mirena coil is in widespread use.
Phillips
V
V
Department of Pathology, Royal Group of Hospitals Trust, Grosvenor Road, Belfast BT12 6BL, Northern Ireland, UK.
Graham
C T
CT
Manek
S
S
McCluggage
W G
WG
D000328:Adult; D001284:Atrophy; D003271:Contraceptive Agents, Female / Q000494:pharmacology*; D004717:Endometrium / Q000187:drug effects* / Q000473:pathology; D005260:Female; D006801:Humans; D007436:Intrauterine Devices, Medicated; D017254:Leukemic Infiltration / Q000139:chemically induced / Q000473:pathology; D016912:Levonorgestrel / Q000494:pharmacology*; D008875:Middle Aged; D045167:Progesterone Congeners / Q000494:pharmacology
D003271:Contraceptive Agents, Female; D045167:Progesterone Congeners; D016912:Levonorgestrel