Endometriomas (chocolate cysts) are associated with infertility in 17-44% of endometriosis cases. Sampson's theory of retrograde menstruation leading to implantation and growth of endometrial tissue is still widely accepted, but does not fully explain all cases of endometriosis. Factors like genetic predisposition, immunological and hormonal changes, oxidative stress, and environmental toxins likely all contribute to the initiation and maintenance of endometriosis. The disease and associated endometriomas can cause infertility through effects on the endometrium like dysregulation of genes important for embryo implantation, and increased inflammatory cytokines that are cytotoxic and disrupt the uterine environment.

1. Endometriomas & InfertilityEndometriomas & Infertility
Dr. Nagendra S. Sardeshpande
Consultant Gynecologist & Endoscopist
Bombay Hospital Institute of Medical Sciences
Mumbai

2. “Even if peritoneal endometriosis arises
from the implantation of endometrial and
tubal tissue on the surface of the
peritoneum, as I believe it does, this does
not prove that all instances of
endometrium-like tissue involving the
peritoneum arises from this source”
John A. Sampson, 1927

3. IntroductionIntroduction
Endometriosis is a benign, estrogen
dependent gynecological disease affecting
5-10% of women of reproductive age (20-
40% of women undergoing ART) with
symptoms including chronic pain,
dysmenorrhoea, dyspareunia & infertility
Endometriomas
17% of subfertile women
 17-44% of endometriosis

4. EndometriomaEndometrioma
EtiologyEtiology
Superficial implant with invagination of
ovarian cortex secondary to bleeding
(Hughesdon, 1957)
Cortex becomes internal wall
Invagination of ovarian cortex secondary
to metaplasia of coelomic epithelium
(Donnez, 1996)
Recurrence due to metaplastic epithelium
within ovary
Endometriotic transformation of functional
cysts (Nezhat, 1992)

5. “Any path which narrows future
possibilities may become a trap. Humans
are not threading their way through a
maze; they scan a vast horizon filled with
unique opportunities”
Kevin Anderson

6. Sampson RevisitedSampson Revisited
 Sampson noted retrograde
flow & intravasation of dye
during menstruation & not
with intact endometrium
 The term “endometriosis” did
not exist
 Sampson, from radiologic
studies, inferred retrograde
endometrial sloughing into
Fallopian tubes & veins
 Coined the term
“implantation adenomas”
Sampson JA. Am J Obstet, 78:
161-75; 1918

7. Sampson’s Theory of RetrogradeSampson’s Theory of Retrograde
DisseminationDissemination
Evidence Supporting Implantation Theory
 Viable cells obtained from menstrual affluent &
peritoneal fluid
 Endometrial cells grow in peritoneal cavity
 Retrograde menstruation almost universal
phenomenon
 Association of endometriosis with obstruction of
menstrual flow
 Transtubal, lymphatic, hematologic or iatrogenic
deposition
D’Hooghe TM, Debrock S.Hum Reprod Update, 8:
84-8; 2002

8. Sampson’s Theory of RetrogradeSampson’s Theory of Retrograde
DisseminationDissemination
Evidence Contradicting Implantation Theory
 Studies were with “chocolate cysts” with few
histologically proven endometriomas
 Focused only on severe disease
 Inferred that pelvic endometriosis was from “leaking”
endometriomas
 Assumed that mode of spread similar to ovarian cancer
 Multiple extrapolations & hypotheses without
supporting evidence
 No photomicrographic proof of initial attachment of
endometrial cells to peritoneum / ovary
 Cannot explain distant / male endometriosis
Redwine DB in Redwine DB (ed): Surg Mgt Endomet, NY,
Martin Dunitz, Taylor & Francis Gr; 2004

9. Predisposition to EndometriosisPredisposition to Endometriosis
Immunological ChangesImmunological Changes
NK Cell Dysfunction
 Increased number Killer Cell Inhibitory
Receptors (KIR) in circulating & peritoneal
NK cells
 Increased ICAM-1 & p40 subunit of IL-2
(potent inhibitors of NK cells) in endometrial
cells
 Increased PGE2? (inhibitor of NK cells, T
cells & macrophages)
Finas D et al. Hum Reprod, 23 (5): 1053-62;
2008

10. Predisposition to EndometriosisPredisposition to Endometriosis
Immunological ChangesImmunological Changes
Macrophage Dysfunction
 Increased production of cytokines (BLyS) associated
with humoral immunity & autoantibodies
 Increased TNF alpha production
T Cell Dysfunction
 Altered Th1:Th2 ratios with induction of humoral
immunity in ectopic endometrium
 Increased T-cell apoptosis
B Cell Dysfunction
 Increased levels of autoantibodies
Parham P. The Immune System (2nd
ed), NY, Garland
Sci; 2005

11. Predisposition to EndometriosisPredisposition to Endometriosis
Genetic FactorsGenetic Factors
Endometrium
Increased expression of cell cycling &
anti-apoptotic genes
-Dysregulation of cell cycle genes GOS2
& SALP controlling mitosis
-Increased Ki67 gene expression
(indicative of dividing cells)
-Increased expression of Bcl-2
Gaetje R et al. Fertil Steril, 87: 651-6; 2007

12. Predisposition to EndometriosisPredisposition to Endometriosis
Genetic FactorsGenetic Factors
Endometrium
 Increased expression of embryonic genes
-Aberrant methylation of HOXA10 and 11
-Higher expression of WNT7A & PAX8
 Aberrant methylation of PR-B receptor gene
in response to TNF alpha
Immune System
 Increased CD-158A gene expression (NK cell
inhibitor) in NK cells
Wu Y et al. Am J Obstet Gynecol, 192; 2005

13. Initiation of EndometriosisInitiation of Endometriosis
Oxidative StressOxidative Stress
 Reduced levels of SOD, glutathione
peroxidase, xanthine oxidase & serum
paroxanase-1 (prevents oxidation of LDL) in
few studies
 Reactive oxygen species (released by
macrophages & mononuclear cells) increase
VEGF production via glycodelin
 NO & H2O2 activate cell adhesion molecules
via NFkb & AP-1
DeFrere S et al. Gynecol Obstet Inv, 65: 145-54;
2008

14. Initiation of EndometriosisInitiation of Endometriosis
Environmental AgentsEnvironmental Agents
Environmental Estrogens
 Bisphenol A reduce vaginal size, thins
endometrial lamina propria & induces ER
alpha & PR in endometrium
Dioxins
 Activates ER beta
 Suppresses CMI & humoral immunity
 Increases endometriotic lesions in primates
Edwards TM, Myers JP. Environ Health Persp,
115: 1264-70; 2007

15. Initiation of EndometriosisInitiation of Endometriosis
Environmental Agents & EpigeneticEnvironmental Agents & Epigenetic
ModulationModulation
 SF1 methylated (inactive)
in normal endometrium
 Toxins demethylate SF1
which is activated by SF2
 Overexpression of ER
alpha & downregulation
of ER beta & PR
 Increased steroidogenesis
& endometrial
proliferation
Dolinoy DC et al. Reprod
Toxicol, 23: 297-307; 2007

16. Maintenance of EndometriosisMaintenance of Endometriosis
Endogenous HormonesEndogenous Hormones
Evidence Supporting Role of Hormones
 Requires estrogen (rare in childhood & after
menopause)
 Rare in ovarian dysgenesis
 Hyperprogestogenic, hypoestrogenic states
(pregnancy, breast feeding, aromatase
inhibitors, GnRH analogues, progestins)
beneficial
 Tissues express E & P receptors
Gurates B, Bulun SE. Semin Reprod Med, 21: 125-
34; 2003

17. Maintenance of EndometriosisMaintenance of Endometriosis
Endogenous HormonesEndogenous Hormones
Estrogen
 Aromatase expression in endometriotic
tissue
 Estrogen activates EMMPRIN (glycosylated
transmembrane protein) which activates
MMP (involved in endometrial cell
adherence & proliferation)
Braundmeier AG et al. J Clin Endocrinol
Metab, 91: 2358-65; 2006

18. Maintenance of EndometriosisMaintenance of Endometriosis
Endogenous HormonesEndogenous Hormones
Progesterone
 Downregulates PR-B but not PR-A receptor
(failure of hypermethylation) in endometriosis
 Unpredictable response
Androgens
 5alpha reductase activity demonstrated in
endometriosis
 May stimulate aromatase activity in low
concentrations
Wu Y et al. Epigenetics, 1: 106-11; 2006
Carneiro MM et al. BJOG, 115: 113-7; 2008

19. Maintenance of EndometriosisMaintenance of Endometriosis
Role of IronRole of Iron
 Peritoneal macrophage heme-
oxygenase 1 (HO1) oxidises
hemoglobin to generate iron, CO
& bilirubin
 Iron (as transferrin) ingested by
macrophages & removed as
ferretin
 Defective HO1 leads to Hb-Hp
(haptoglobin) complexes which
damage mesothelium &
stimulates inflammatory
cytokines
Demir AY et al. Proteonomics, 4:
2608-23; 2004
Hemosiderin laden
macrophages

20. Maintenance of EndometriosisMaintenance of Endometriosis
Role of IronRole of Iron

21. Maintenance of EndometriosisMaintenance of Endometriosis
InflammationInflammation
 Macrophages secrete
fibronectin, MCP-1, VEGF,
MDGF, IL-8 & TNFalpha
which induce angiogenesis,
endometrial proliferation &
synthesis of collagen
 Macrophages secrete Th2
cytokines IL-4, Il-5, IL-6, IL-
10 &IL-13, TGF beta which
promote B cell immunity &
suppress T cell cytotoxicity
Berbic M et al. Hum Reprod, 24:
325-32; 2009
Inflammatory stromal reaction
in endometriosis

22. EndometriosisEndometriosis
Mechanism of Adhesion FormationMechanism of Adhesion Formation
 PAI-1
-Inhibits fibrinolysis
 TGF
-Growth inhibitor of epithelium
 PDGF
-Migration & proliferation of fibroblasts, smooth muscle cells
& monocytes
 FGF
-Angiogenesis & proliferation of fibroblasts & macrophages
 VEGF
-Angiogenesis
-Produced by hypoxic endometrium, macrophages & T cells
 EGF
-Promotes granulation tissue formation
 Vaze MN et al. Vet World. 3 (12): 561-6; 2010

23. EndometriosisEndometriosis
Mechanism of Adhesion FormationMechanism of Adhesion Formation

24. EndometriosisEndometriosis
Effect on FertilityEffect on Fertility
Endometrial Changes
 Out of phase endometrium
 Glycodelin gene downregulation (affecting embryo
implantation)
 Lack of integrin beta3 in proliferative phase with
lack of MMP activation and defective embryo
adhesion, migration & implantation
Immunological Changes
 TNFalpha cytotoxic
 Cytokines, PG cytotoxic & increase uterine & tubal
motility
 Ovulatory dysfunction?
Minici F et al. Hum Reprod, 23: 530-7; 2008

25. Etiopathogenesis of EndometriosisEtiopathogenesis of Endometriosis
Clinical ImplicationsClinical Implications
Role of Multiple Therapies
 Combined GnRH analogue &
aromatase inhibitors
Novel Therapies
 COX2 inhibitors
 Immunomodulators
 VEGF / TNF alpha inhibitors
 PR modulators
 Statins
Rebirth of Older Therapies
 Danazol
 Gestrinone

26. AdenomyosisAdenomyosis
PredispositionPredisposition
Endometrial Changes
 Aromatase activity in endometrium
 Increased PRL, PRL receptor, HCG, LH receptor
expression
 Higher levels of MMP-2 in endometrial epithelium
& stroma predispose to basement membrane
breakdown & invasion
 Increased IL-8 & ENF-78 by endometrium induces
chemokine secretion by macrophages
 Increased ECAM (E-cadherin) expression
Tanwar PS et al. Biol Reprod, 81: 545-52; 2009
Ueki K et al. Int J Gynec Pathol, 23: 248-58; 2004

27. AdenomyosisAdenomyosis
PredispositionPredisposition
Immunological Changes
 Increased GM-CSF secretion by macrophages
induces endometrial epithelial & stromal
proliferation
 Increased humoral response
Genetic Changes
 Increased Survivin gene (chromosome 17q25)
expression which inhibits capsase induced
endometrial cell apoptosis
Zaitseva M et al. Mol Hum Reprod, 13: 577-85; 2007
White C et al. Reprod Biol Endocrinol, 2: 76; 2004

28. AdenomyosisAdenomyosis
Initiation & MaintenanceInitiation & Maintenance
Neovascularization
 VEGF, PDGF, MIF &
TNF induce
vascularization,
increase vascular
permeability &
increase endometrial
proliferation
Peng L et al. Fertil Steril,
91: 2664-75; 2009

29. Metaplasia Theory of EndometriosisMetaplasia Theory of Endometriosis
 Peritoneal Disease
-Metaplastic potential of pelvic
mesothelium
 Ovarian Endometriomas
-Invagination of the cortex
-Metaplasia of coelomic
epithelium
 Rectovaginal Nodules
-Metaplasia of mullerian rests
into endometriotic glands
-Secondary infiltration of
peritoneal endometriosis of
POD
Glandular element with
surrounding stromal & smooth
muscle hyperplasia in
endometriosis

30. Metaplasia Theory of EndometriosisMetaplasia Theory of Endometriosis
Evidence Supporting Metaplasia
Theory
 Epithelial invagination in
continuation with ectopic
endometrial tissue
 Endometriomas in MRKH
syndrome
 Primordial follicles found
surrounding endometrioma
 Presence of smooth muscle, stoma
admixed with endometrium
 Absence of evolution after removal
of nodule
Vigano P in Garcia-Velasco JA, Rizk
BRMB (ed): Endometriosis, St. Louis
(USA), Jaypee Publishers; 2010
Smooth muscle & stroma in
rectovaginal nodule

31. Predisposition toPredisposition to
EndometriosisEndometriosis
Endometrial ChangesEndometrial Changes
 Prolonged proliferative phase
of ectopic endometrium
 Electron microscopic findings
include persistent mitosis,
increased glycogen
deposition, incomplete
ciliogenesis, giant
mitochondria & nucleolar
channel systems in secretory
phase of cycle
 Increased aromatase activity
Szymanowski K. Eur J Obstet
Gynecol, 132: 107-10; 2007
Increased glycogen
Increased mitosis & nucleolar
channel systems

32. Predisposition to EndometriosisPredisposition to Endometriosis
Endometrial ChangesEndometrial Changes
 Alteration in TNFalpha induced cell apoptosis via
altered sphingomyelinase mediated pathway with
increased cell survival
 Increased TNF alpha receptors
 Increased FAS ligand expression by endometrial
epithelial & stromal cells which induces T-cell
apoptosis
 IL-6 (secreted by monocytes, macrophages,
endothelial cells & endometrium) increases Endo-
1 (a haptoglobin) which blocks macrophage
phagocytosis
Hudelist G et al. Reprod Sci, 14: 798-805; 2007

33. Predisposition to EndometriosisPredisposition to Endometriosis
Immunological ChangesImmunological Changes