*2.3.1 Endometrial safety*

Endometrial safety is a grill for challenge menopausal and postmenopausal HTs, because the bleeding and the risks of hyperplasia and cancer are discussed in the 70 years of MHT history, years with many waves of increased and decreased enthusiasm on the benefits and risks of MTH. The aim of replacement and restoration of ovarian functions in postmenopausal women with estrogens and progesterone is only a modest attempt for women's health, because there are missing other molecules as testosterone, activin, inhibin, anti-Müllerian hormone (AMH) and insulin-like growth factor 1 (IGF-1), and many other connected to these, which have an immense significance on a woman's physiology, and all of them may influence endometrial actions of MHT [84].

The endometrial safety means the protection from non-invasive proliferative lesions—hyperplasia, and invasive—carcinoma.

• If the analysis of histological data is done after the criteria of the years 80′ the endometrium must be with secretory changes in the sequential regimens, and atrophy, or inactive after the continuous—combined regimens.

**67**

*Endometrial Histology and Safety on Non-Oral Routes of Hormone Therapy...*

hyperplasia, in the presence of a thin (<4 mm) endometrium [92].

*2.3.2 Endometrial assessment on menopausal hormone therapy*

pathologist in connection to bleeding pattern on MRT [78].

any hyperplasia, or any estrogenic effect.

In 2002, Van Gorp and Neven [50] have published in "Maturitas" the Journal of the European Menopause and Andropause Society a review of endometrial safety on MHT. They presented a Finish study [93] on the endometrial safety after short term HT (12 months) regarding percutaneous estradiol-gel delivering E2 1.0 mg/ day, or patch (delivering E2 50 pg/day) in a sequential regimen with oral dydrogesterone 10 mg/day for first 12 days of the cycle. The endometrial biopsies—collected during the 9th to 12th days of the progestogen days in both groups did not revealed

MHT must be assessed when women start therapy, with an annual follow-up or when there is a minimal suspicion of endometrial abnormality regarding bleeding, or when it is an abnormality at transvaginal scan by endometrial biopsy, with Pipelle Cornier suction curette, Kevorkian or Vabra curette, or by fractional curettage—endometrium and endocervix, or by out-patient hysteroscopy. Hysteroscopy permits to avoid the loss of an isolated focus of endometrial cancer, atypical hyperplasia or polyp which easily can be missed by blind sampling procedures [70]. On another hand hysteroscopy is prone to depict the changes of endometrial surface, vessels, which are very much discussed by the Australian gynecologists and

Besides some inconvenients which will be discussed in the next subchapter, the endometrial sample obtained with Pipelle Cornier suction curette has been shown to be as accurate as conventional dilation and curettage in the diagnosis of endometrial pathology in premenopausal and postmenopausal women [94]. The amount

• If the analysis of histological data is done after the criteria of the years 90′ endometrial safety means to reduce the risk of hyperplasia and carcinoma development, in fact to down-regulate estrogen induced proliferation, with disappearance of mitosis from the endometrial glands, and stroma, or ≤2 mitoses at 1000 cells, the so-called proliferation index, or mitotic index [44].

The impact of vaginal progesterone on the endometrial safety is very important, being considered that the duration is more important than the dose [85]. After the results of the Scandinavian study regarding long cycle progestogen association to estrogen—at 3 months interval [86], which was updated in *Cochrane Database Systematic Review* [87, 88], today it is considered that it is important to combine a progesterone/progestogen with the estrogen in the beginning of the treatment, to control early endometrial growth. If one considers these Scandinavian studies, one may accept a non-opposed estrogen administration as Van Gorp and Neven recommend [50]. Minimum 10 days/month of vaginal administration provides protection in sequential regimens, in a dose of 45 mg/day at 4% in cream, or every other day in a dose of 100 mg/day for up to 3–5 years (off-label use) [44], but this aim is not accomplished with transdermal micronized progesterone [89, 90]. The daily balance of non-oral estrogen by non-oral progesterone/progestogen in continuous combined regimens is more stable than the balance of oral administration, and endometrial carcinoma risk is also reduced, as since long time ago it was reported after 8 years of use [91]. If oral and non-oral routes of progesterone/progestogen administration are proved to be less effective in treatment of atypical endometrial hyperplasia, and unable to stop most early invasive cancers, the intrauterine system with levonorgestrel 20 μg /day associated to transdermal estrogens was demonstrated to achieve these aims after 3 years administration. From 20 Belgian women, only one asymptomatic women with atypical hyperplasia at baseline at 3 years was discovered with focal residual non-atypical

*DOI: http://dx.doi.org/10.5772/intechopen.89046*

*Endometrial Histology and Safety on Non-Oral Routes of Hormone Therapy... DOI: http://dx.doi.org/10.5772/intechopen.89046*

• If the analysis of histological data is done after the criteria of the years 90′ endometrial safety means to reduce the risk of hyperplasia and carcinoma development, in fact to down-regulate estrogen induced proliferation, with disappearance of mitosis from the endometrial glands, and stroma, or ≤2 mitoses at 1000 cells, the so-called proliferation index, or mitotic index [44].

The impact of vaginal progesterone on the endometrial safety is very important, being considered that the duration is more important than the dose [85]. After the results of the Scandinavian study regarding long cycle progestogen association to estrogen—at 3 months interval [86], which was updated in *Cochrane Database Systematic Review* [87, 88], today it is considered that it is important to combine a progesterone/progestogen with the estrogen in the beginning of the treatment, to control early endometrial growth. If one considers these Scandinavian studies, one may accept a non-opposed estrogen administration as Van Gorp and Neven recommend [50]. Minimum 10 days/month of vaginal administration provides protection in sequential regimens, in a dose of 45 mg/day at 4% in cream, or every other day in a dose of 100 mg/day for up to 3–5 years (off-label use) [44], but this aim is not accomplished with transdermal micronized progesterone [89, 90]. The daily balance of non-oral estrogen by non-oral progesterone/progestogen in continuous combined regimens is more stable than the balance of oral administration, and endometrial carcinoma risk is also reduced, as since long time ago it was reported after 8 years of use [91]. If oral and non-oral routes of progesterone/progestogen administration are proved to be less effective in treatment of atypical endometrial hyperplasia, and unable to stop most early invasive cancers, the intrauterine system with levonorgestrel 20 μg /day associated to transdermal estrogens was demonstrated to achieve these aims after 3 years administration. From 20 Belgian women, only one asymptomatic women with atypical hyperplasia at baseline at 3 years was discovered with focal residual non-atypical hyperplasia, in the presence of a thin (<4 mm) endometrium [92].

In 2002, Van Gorp and Neven [50] have published in "Maturitas" the Journal of the European Menopause and Andropause Society a review of endometrial safety on MHT. They presented a Finish study [93] on the endometrial safety after short term HT (12 months) regarding percutaneous estradiol-gel delivering E2 1.0 mg/ day, or patch (delivering E2 50 pg/day) in a sequential regimen with oral dydrogesterone 10 mg/day for first 12 days of the cycle. The endometrial biopsies—collected during the 9th to 12th days of the progestogen days in both groups did not revealed any hyperplasia, or any estrogenic effect.

#### *2.3.2 Endometrial assessment on menopausal hormone therapy*

MHT must be assessed when women start therapy, with an annual follow-up or when there is a minimal suspicion of endometrial abnormality regarding bleeding, or when it is an abnormality at transvaginal scan by endometrial biopsy, with Pipelle Cornier suction curette, Kevorkian or Vabra curette, or by fractional curettage—endometrium and endocervix, or by out-patient hysteroscopy. Hysteroscopy permits to avoid the loss of an isolated focus of endometrial cancer, atypical hyperplasia or polyp which easily can be missed by blind sampling procedures [70]. On another hand hysteroscopy is prone to depict the changes of endometrial surface, vessels, which are very much discussed by the Australian gynecologists and pathologist in connection to bleeding pattern on MRT [78].

Besides some inconvenients which will be discussed in the next subchapter, the endometrial sample obtained with Pipelle Cornier suction curette has been shown to be as accurate as conventional dilation and curettage in the diagnosis of endometrial pathology in premenopausal and postmenopausal women [94]. The amount

*Hormone Therapy and Replacement in Cancer and Aging-Related Diseases*

than the patients with secretory transformation [81].

The variations of endometrial answers to transdermal estrogen and vaginal micronized progesterone are reduced in comparison to HT oral route, according to more stable transdermal/percutaneous estrogen serum levels, and progesterone uterine first pass. When the bleeding pattern is observed comparative to endometrial histology, the patients with proliferative histologic pattern are bleeding early

An Italian prospective study [82] evaluated and compared uterine bleeding in 100 early postmenopausal women (12–36 months after last mensis) on a sequential regimen with both hormones administered non-oral, *versus* the same regimen with oral natural progesterone (NP). All groups were treated with transdermal 17β-E2 50 μg/day, and the NP was 100 mg or 200 mg per day from the 14th day to the 25th day of each 28-day cycle. After 12 cycles of treatment, no significant differences were observed in endometrial thickness between groups, suggesting that all treatments are effective in balancing the estradiol effects on endometrium. Regarding bleeding control, patients in the group with sequential vaginal NP showed a higher number of episodes of regular bleeding than patients in groups with oral NP, and fewer episodes of spotting. Authors' conclusion was that transdermal estrogen combined with vaginal 100 mg micronized NP from the 14th day to the 25th day of each 28-days cycle leads to a good cycle control, and provides excellent patient satisfaction without serious side-effects. The better control of bleeding was associated with a higher treatment compliance in patients who received vaginal NP, with a larger percentage of women completing the study. The authors recommend to start treatment with the lower dose of NP (100 mg/day) to avoid the risk of amenorrhea

An Italian study which is considered with the longest duration—3 years, has prospectively evaluated the bleeding/amenorrhea in 30 postmenopausal women treated with continuous transdermal E2 gel and every-other-day vaginal micronized progesterone in capsules [42]. They report that 4 (13%) of 30 patients withdrew from the study because of bleeding (3 for heavy bleeding and 1 for repeated spotting), and an higher incidence of amenorrhea (82%) than commonly reported

**2.3 Endometrial safety: endometrial assessment on MHT and endometrial** 

Endometrial safety is a grill for challenge menopausal and postmenopausal HTs, because the bleeding and the risks of hyperplasia and cancer are discussed in the 70 years of MHT history, years with many waves of increased and decreased enthusiasm on the benefits and risks of MTH. The aim of replacement and restoration of ovarian functions in postmenopausal women with estrogens and progesterone is only a modest attempt for women's health, because there are missing other molecules as testosterone, activin, inhibin, anti-Müllerian hormone (AMH) and insulin-like growth factor 1 (IGF-1), and many other connected to these, which have an immense significance on a woman's physiology, and all of them may influ-

The endometrial safety means the protection from non-invasive proliferative

• If the analysis of histological data is done after the criteria of the years 80′ the endometrium must be with secretory changes in the sequential regimens, and

atrophy, or inactive after the continuous—combined regimens.

**66**

with 200 mg/day.

(70%) with oral compounds [83].

ence endometrial actions of MHT [84].

lesions—hyperplasia, and invasive—carcinoma.

*2.3.1 Endometrial safety*

**histology on non-oral regimens of MHT**

of endometrial tissue is very little, sometimes much less than that demanded by pathologists unused to such biopsies, but when the microscopy is corroborated to ultrasound, the medical staff can be reassured of safety [94].

Double layer endometrial thickness is usually measured at the thickest part in the longitudinal plane, by scanning from cornua to cornua. The poorly echogenic layer surrounding the highly echogenic endometrium is not included in the measurement. Endometrial thickness is evaluated to determine the mean of three measurements and excluding the possible endometrial fluid from the measurement. One must take into account in elder patients with atrophic endometrium after MHT that the fluid may be blood, even the patients do not bleed. In oral and non-oral MHT the endometrial thickness has an initial increase—more important after sequential regimens, with a consistent decrease at 36 months when on continuous combined regimens, so the endometrium becomes significantly thinner than at baseline. These data are controverted by the previously presented prospective Italian study, which after 12 cycles of non-oral sequential treatment discovered no significant differences in endometrial thickness between groups, suggesting that all treatments are effective in balancing the effects of percutaneous E2 on endometrium [82].

The prospective Italian study on continuous-combined non-oral MHT [42] revealed a smaller increase of the endometrial thickness comparative to that reported by a similar North American oral regimen; the baseline-to-endpoint increases in endometrial thickness were 7.8 ± 3.8 mm, and 1.8 ± 3.2 mm, respectively [95] versus the Italian data, where the mean endometrial thickness increase was only 0.7 mm, after 6 months treatment, and endometrial atrophy was registered after 3 years (end of study), in all cases that completed the study [twenty-three (76.7%) women from 30 healthy cases in natural menopause]. The British study [96] revealed a continuous increase of endometrial thickness from baseline [3.3 (1.7)] mm to the mean of 5.3 (3.3) mm by 24 weeks (P < 0.001), and of 5.5 (2.8) mm after 48 weeks, with continuous combined transdermal E2 l.1 mg/day plus 4 mg/day NP cream, (P < 0.001), being a non-significant increase from 24th to 48th weeks, but the increase was more important when it was inadequate endometrial opposition (4.7 mm vs. 7.6 mm respectively, P < 0.001). These results and the histological aspects of proliferative endometrium with inadequate progesterone opposition after 48 weeks HT—which will be analyzed in next subchapter, sustain the actual recommendation to avoid transdermal natural progesterone.

#### *2.3.3 Endometrial histology with non-oral MHT*

Endometrial histological assessment is a very important part of the continuing follow up of women taking MHT. There are few studies on endometrial histology after MHT with both hormones administered non-orally in comparison to oral route.

**Table 3** is listing such studies, which were published after WHI, with some North American studies before the year 2000; the studied estrogens and progestogens were transdermal administered, and the soft capsules of micronized progesterone were vaginally administered. Because it is the rule of baseline endometrial assessment, the studies are comparing the histology at pre, and post-treatment, or in some of them to oral MHT. The endometrial biopsy is done before treatment, and between 9th and 14th days of treatment cycle, to evaluate the progesterone/ progestogen effect (similar to cases on oral MHT), in the sequential regimens. The endometrial specimen is collected after 6 months, no matter which day, in continuous-combined MHT regimens.

Endometrial safety is assessed in terms of prevention of estrogen-induced hyperplasia. Progesterone supplementation may cover the objective of endometrial protection from benign hyperplasia from the STRAW—3 stage (2012), or when it is

**69**

*Endometrial Histology and Safety on Non-Oral Routes of Hormone Therapy...*

**Type and dose of progestegen/ progesterone**

Norethindrone acetate 140, 250, or 400 μg/day

Continuous combined Trd NETA: 170 μg/ day or sequential Trd NETA: 350 μg/day, or sequential oral NETA 1 mg/day or sequential DYD 20 mg/day

LNG mg/day of 0.015; 0.030; and 0.040

 (50 μg/day E2 for 2 wks, followed 50 μg/day E2–10 μg/day LNGl for 2 wks)

> Micronized progesterone, soft capsules 100 mg everyother-day (or at 48 h)

(vaginal)

Natural progesterone cream 40 mg/day (transdermal)

NETA 125 μg/day No hyperplasia

(75 μg/dy E2 for 2 weeks followed by

 (100 μg/day E2 for 2 wks followed by 100 μg/day E2–20 μg/day LNG for 2 wks)

Continuous combined, 2 groups with once a week Patch 17 β estradiol:+ LNG 4.4/1.39 or 4.4/2.74/day or

1. Group oral: 2 mg/d E2 valerate (E2V) 21 days, E2V

2. Group oral: 2 mg/d -mcr E2 14 days, 2 mg/d mcrE2

3. Group mixed: 17β E2 patch (25 μg/d 21 days) plus oral MPA (10 mg/5 mg/day) last 12 days 4. Group fully non-oral: 1 g/d 17β E2 gel 28 days plus 200 mg/d vaginal micronized VMP last 12 days

75 μg/day E2–15 μg/day LNG for 2 wks)

**Hyperplasia, type 1/2 cancer**

0.8% (1 of 123), 1% (1 of 98),

2 cases of simple hyperplasia were reported (1 in each lowdose progestogen group)

Endometrial protection for all

**(authors conclusions/ commments)**

**P value**

1.1% (1 of 89) (P < 0.001)

No hyperplasia

No hyperplasia

No hyperplasia Atrophy: 100%

No cancer

MPA

10 (27%) endometrial proliferation, 2 (5%) complex hyperplasia, 1 with (mild) atypia, and 1 without atypia

1 case with simple hyperplasia without atypia after 24 months, on transdermal estrogen +5 mg

(incidence 1/43 cases) is inside the oncological safety (2 cases/100 women year) No carcinoma

groups

*DOI: http://dx.doi.org/10.5772/intechopen.89046*

**Type and dose of estrogen**

Continuous combined estradiol 50 μg/day

Continuous combined or sequential E2 50 μg/day

Continuous combined, once a week patch E2 0.045 mg/day

Sequential: 3 groups 1. patches of 15 cm2

2. 22.5 cm2

3. 30 cm2

4.5/3.75 mg/day

Continuous combined 17 β estradiol gel, 1.5 mg/day

Continuous combined oestradiol 1 mg/day transdermal daily

Continuous combined estradiol matrix 25 μg/day

Sequential HT

plus CYP 10 days

plus DYD 14 days

**Authors/study group, year Duration of use**

Archer DF, Furst K, et al., 1999 [97] 3, 6, 9, and 12 months after initiation of treatment

Ylikorkala O, Rozenberg S, 2000

Shulman LP, Yankov V, Uhl K, 2002 [99] 12 months

Sturdee DW, van de Weijer P, von Holst T, 2002 [100] 12 months

Dando TM, Perry CM (2004) [101] 17 beta-E2/LNG transdermal system 12 months, RCT

Cicinelli E, de Ziegler D, Colafiglio G, et al.,

2005 [42] 3 years montoring

Vashisht A, Wadsworth F, Carey A, Carey B, Studd J, 2005 [96] 48 weeks (54 cases, only 41 completed the study)

Samsioe G, Dvorak V, Genazzani AR, et al., Estalis 25/125 Study Group, 2007

Russu M, Terzea D, Hudiţă D, 2009 [103] 24 months monitoring

[102] 96 weeks

[98] 12 months


*Endometrial Histology and Safety on Non-Oral Routes of Hormone Therapy... DOI: http://dx.doi.org/10.5772/intechopen.89046*

*Hormone Therapy and Replacement in Cancer and Aging-Related Diseases*

ultrasound, the medical staff can be reassured of safety [94].

in balancing the effects of percutaneous E2 on endometrium [82].

mendation to avoid transdermal natural progesterone.

*2.3.3 Endometrial histology with non-oral MHT*

ous-combined MHT regimens.

The prospective Italian study on continuous-combined non-oral MHT [42] revealed a smaller increase of the endometrial thickness comparative to that reported by a similar North American oral regimen; the baseline-to-endpoint increases in endometrial thickness were 7.8 ± 3.8 mm, and 1.8 ± 3.2 mm, respectively [95] versus the Italian data, where the mean endometrial thickness increase was only 0.7 mm, after 6 months treatment, and endometrial atrophy was registered after 3 years (end of study), in all cases that completed the study [twenty-three (76.7%) women from 30 healthy cases in natural menopause]. The British study [96] revealed a continuous increase of endometrial thickness from baseline [3.3 (1.7)] mm to the mean of 5.3 (3.3) mm by 24 weeks (P < 0.001), and of 5.5 (2.8) mm after 48 weeks, with continuous combined transdermal E2 l.1 mg/day plus 4 mg/day NP cream, (P < 0.001), being a non-significant increase from 24th to 48th weeks, but the increase was more important when it was inadequate endometrial opposition (4.7 mm vs. 7.6 mm respectively, P < 0.001). These results and the histological aspects of proliferative endometrium with inadequate progesterone opposition after 48 weeks HT—which will be analyzed in next subchapter, sustain the actual recom-

Endometrial histological assessment is a very important part of the continuing follow up of women taking MHT. There are few studies on endometrial histology after MHT with both hormones administered non-orally in comparison to oral route. **Table 3** is listing such studies, which were published after WHI, with some North American studies before the year 2000; the studied estrogens and progestogens were transdermal administered, and the soft capsules of micronized progesterone were vaginally administered. Because it is the rule of baseline endometrial assessment, the studies are comparing the histology at pre, and post-treatment, or in some of them to oral MHT. The endometrial biopsy is done before treatment, and between 9th and 14th days of treatment cycle, to evaluate the progesterone/ progestogen effect (similar to cases on oral MHT), in the sequential regimens. The endometrial specimen is collected after 6 months, no matter which day, in continu-

Endometrial safety is assessed in terms of prevention of estrogen-induced hyperplasia. Progesterone supplementation may cover the objective of endometrial protection from benign hyperplasia from the STRAW—3 stage (2012), or when it is

of endometrial tissue is very little, sometimes much less than that demanded by pathologists unused to such biopsies, but when the microscopy is corroborated to

Double layer endometrial thickness is usually measured at the thickest part in the longitudinal plane, by scanning from cornua to cornua. The poorly echogenic layer surrounding the highly echogenic endometrium is not included in the measurement. Endometrial thickness is evaluated to determine the mean of three measurements and excluding the possible endometrial fluid from the measurement. One must take into account in elder patients with atrophic endometrium after MHT that the fluid may be blood, even the patients do not bleed. In oral and non-oral MHT the endometrial thickness has an initial increase—more important after sequential regimens, with a consistent decrease at 36 months when on continuous combined regimens, so the endometrium becomes significantly thinner than at baseline. These data are controverted by the previously presented prospective Italian study, which after 12 cycles of non-oral sequential treatment discovered no significant differences in endometrial thickness between groups, suggesting that all treatments are effective

**68**


*E2, estradiol; LNG, levonorgestrel; NETA, norethisteron enanthate; E2V, estradiol valerate; CYP, cyproterone acetate; DYD, dydrogesterone; VMP, vaginal micronized progesterone.*

#### **Table 3.**

*Studies on endometrial histology and safety after non-oral routes of MHT.*

the onset of menstrual cycle irregularities, which may have hyperplasia as histologic substrate.

The effects of hormones are appreciated on the architecture and cytological aspects of the epithelium, glands, stroma, and vessels. Mitoses are considered for estrogens proliferative effect, and subnuclear glycogen accumulation, and intraluminal secretions for high grade progesterone effects, or the cytoplasmic vacuolisation, for low grade progesterone secretory change [104, 105]. When progesterone regulation effect is not possible to be assessed with accuracy, the degree of proliferation suppression—mild, moderate, strong is a surrogate for evaluation, as it was done in the Romanian analysis [103].

There are many pathologists involved in endometrial assessment on/after MHT in Europe, USA, Canada, South Africa. **Table 4** presents an adaption of endometrial changes on MHT according to International Society of Gynecological Pathologists (2019) [112, 113], WHO (2014) cited by [123], British Society for Gynecological Endoscopy (2014) [120], FIGO (2009, 2012) cited by [119]. Deligdish [104], Feeley and Wells [94] present very understandable the endometrial effects of MHT, including a wide spectrum of morphologic features, known since long time on oral MHT, and less on non-oral routes, which are. Recently discussed by Owings and Quick [105]. For simplicity of understanding, **Table 4** contains the classification of endometrial histology changes, with special attention to the hyperplasia [WHO, 1994, with 4 types updated by WHO, 2014, cited by [123], which was recommended for use by the Royal College of Obstetricians and Gynecologists (RCOG), and the British Society for Gynecological Endoscopy (BSGE) [120], with only 2 categories, as it is mentioned in the table, and it was discussed at the beginning of the subchapter].

The first three types (unassessable, inactive, atrophic) may impose some problems to the pathologist, because there is a small amount of tissue—obtained with Pipelle suction curette, and the British pathologists Feeley and Wells [94] appreciate that this condition can be associated to thin, regular endometrium at hysteroscopy, or with an endometrial thickness not exceeding 7 mm, at sonography [108], and though the pathologist can therefore be reassured that where the endometrial cavity has been entered and little or no endometrial tissue is obtained, there is very little likelihood of important endometrial pathology to be present. The assessment of secretory endometrium may be confused by artifacts of fragments disruption, which may induce focal changes of glandular tortuosity and crowding. The diagnosis of low grade cytological atypia is very difficult to be appreciated [94]. In a progesterone/progestogen rich environment, nuclei of premalignant glands tend to diminish in size, and acquire a rather bland chromatin pattern, which makes them

**71**

*Endometrial Histology and Safety on Non-Oral Routes of Hormone Therapy...*

• Cystically dilated glands lined by single layer of inactive, flattened epithelial cells

• Typical stromal decidual change associated with inactive or weakly secretory glands, induced by

covers formerly named simple and complex hyperplasia without atypia (WHO, 1994)

*Benign hyperplasia* (BH), Mutter [106] or endometrial hyperplasia without atypia (WHO, 2014), which

• Dilated glands with increased nuclear stratification of lining epithelium and increased stromal mitoses.

*Atypical endometrial hyperplasia* (WHO, 2000), or endometrial intraepithelial neoplasia (EIN)—[106, 107]

appear less "atypical". Paradoxically, the nuclei of normal glands become enlarged

*Classification and associated features of histological examination of the Pipelle endometrial biopsy.*

The endometrium aspect depends on the regimen; it may be proliferative, secretory, near atrophic, inactive, or a mixed picture-mixed proliferative and secretory endometrium including crowded and hyperplastic glands, alternating with an edematous, hyperplastic, or decidualized stroma, sometimes with thickened or

Most endometrial biopsies from women on sequential MHT show weak secretory features. Approximately 15% show proliferative activity, although this figure may be less if more than 9 days of progesterone/progestogen is given per cycle. A small proportion are revealing an inactive or atrophic endometrium. Up to 50% of biopsies in cases on continuous combined HT contain minimal tissue for pathological analysis: this correlates well with an atrophic endometrium with no appreciable pathology. Of the 50% with more substantial material, approximately one half presents endometrial atrophy, and one half are showing weak secretory features [94]. The Romanian analysis shows that after complete non-oral route of HT, the proliferative rate and secretory changes were more frequent in the first year, and

and rounded—features associated with atypia [109].

thrombosed blood vessels.

*DOI: http://dx.doi.org/10.5772/intechopen.89046*

• Endometrial tissue insufficient for diagnosis

• Narrow tubular glands lined with cuboidal epithelium

• Epithelial cytoplasmic vacuolation—subnuclear or supranuclear • Glandular luminal secretion in mid-phase and late phase

• Tissue insufficient for diagnosis • No endometrium identified

• Presence of epithelial mitoses

*Pseudo-decidual change*

• No risk of malignancy

• Low risk of malignancy

**Table 4.**

• Simple hyperplasia without atypia:

• Complex hyperplasia without atypia • Crowded and irregular branched glands

• Atypical epithelial cells; high risk of malignancy *Carcinoma* (endometrioid type, non-endometrioid type) *Adapted from WHO (2014) which updated WHO (1994); [106, 107, 121].*

progestogen

*Unassessable* • No tissue identified

*Inactive*

*Atrophic*

*Proliferative*

*Secretory*

*Endometrial Histology and Safety on Non-Oral Routes of Hormone Therapy... DOI: http://dx.doi.org/10.5772/intechopen.89046*

#### *Unassessable*

*Hormone Therapy and Replacement in Cancer and Aging-Related Diseases*

**Type and dose of estrogen**

Intermittent (twice a

*Studies on endometrial histology and safety after non-oral routes of MHT.*

week) Estradiol patch 25 μg/day

*DYD, dydrogesterone; VMP, vaginal micronized progesterone.*

the onset of menstrual cycle irregularities, which may have hyperplasia as histologic

*E2, estradiol; LNG, levonorgestrel; NETA, norethisteron enanthate; E2V, estradiol valerate; CYP, cyproterone acetate;* 

**Type and dose of progestegen/ progesterone**

Intermittent (twice a

100 mg micronized progesterone (vaginal)

week)

**Hyperplasia, type 1/2 cancer**

**(authors conclusions/ commments)**

No apparent endometrial

**P value**

stimulation

The effects of hormones are appreciated on the architecture and cytological aspects of the epithelium, glands, stroma, and vessels. Mitoses are considered for estrogens proliferative effect, and subnuclear glycogen accumulation, and intraluminal secretions for high grade progesterone effects, or the cytoplasmic vacuolisation, for low grade progesterone secretory change [104, 105]. When progesterone regulation effect is not possible to be assessed with accuracy, the degree of proliferation suppression—mild, moderate, strong is a surrogate for evaluation, as it was

There are many pathologists involved in endometrial assessment on/after MHT in Europe, USA, Canada, South Africa. **Table 4** presents an adaption of endometrial changes on MHT according to International Society of Gynecological Pathologists (2019) [112, 113], WHO (2014) cited by [123], British Society for Gynecological Endoscopy (2014) [120], FIGO (2009, 2012) cited by [119]. Deligdish [104], Feeley and Wells [94] present very understandable the endometrial effects of MHT, including a wide spectrum of morphologic features, known since long time on oral MHT, and less on non-oral routes, which are. Recently discussed by Owings and Quick [105]. For simplicity of understanding, **Table 4** contains the classification of endometrial histology changes, with special attention to the hyperplasia [WHO, 1994, with 4 types updated by WHO, 2014, cited by [123], which was recommended for use by the Royal College of Obstetricians and Gynecologists (RCOG), and the British Society for Gynecological Endoscopy (BSGE) [120], with only 2 categories, as it is mentioned in the table, and it was discussed at the beginning of the

The first three types (unassessable, inactive, atrophic) may impose some problems to the pathologist, because there is a small amount of tissue—obtained with Pipelle suction curette, and the British pathologists Feeley and Wells [94] appreciate that this condition can be associated to thin, regular endometrium at hysteroscopy, or with an endometrial thickness not exceeding 7 mm, at sonography [108], and though the pathologist can therefore be reassured that where the endometrial cavity has been entered and little or no endometrial tissue is obtained, there is very little likelihood of important endometrial pathology to be present. The assessment of secretory endometrium may be confused by artifacts of fragments disruption, which may induce focal changes of glandular tortuosity and crowding. The diagnosis of low grade cytological atypia is very difficult to be appreciated [94]. In a progesterone/progestogen rich environment, nuclei of premalignant glands tend to diminish in size, and acquire a rather bland chromatin pattern, which makes them

**70**

subchapter].

substrate.

**Table 3.**

2012 [75] 12 months

**Authors/study group, year Duration of use**

Fernandez-Munga L, Hermenegildo C, Tarin JJ, Garcia-Perez M-A, Cano A,

done in the Romanian analysis [103].


#### *Inactive*

• Narrow tubular glands lined with cuboidal epithelium

#### *Atrophic*

• Cystically dilated glands lined by single layer of inactive, flattened epithelial cells

#### *Proliferative*

• Presence of epithelial mitoses

#### *Secretory*


#### *Pseudo-decidual change*

• Typical stromal decidual change associated with inactive or weakly secretory glands, induced by progestogen

*Benign hyperplasia* (BH), Mutter [106] or endometrial hyperplasia without atypia (WHO, 2014), which covers formerly named simple and complex hyperplasia without atypia (WHO, 1994)


*Atypical endometrial hyperplasia* (WHO, 2000), or endometrial intraepithelial neoplasia (EIN)—[106, 107]


*Adapted from WHO (2014) which updated WHO (1994); [106, 107, 121].*

#### **Table 4.**

*Classification and associated features of histological examination of the Pipelle endometrial biopsy.*

appear less "atypical". Paradoxically, the nuclei of normal glands become enlarged and rounded—features associated with atypia [109].

The endometrium aspect depends on the regimen; it may be proliferative, secretory, near atrophic, inactive, or a mixed picture-mixed proliferative and secretory endometrium including crowded and hyperplastic glands, alternating with an edematous, hyperplastic, or decidualized stroma, sometimes with thickened or thrombosed blood vessels.

Most endometrial biopsies from women on sequential MHT show weak secretory features. Approximately 15% show proliferative activity, although this figure may be less if more than 9 days of progesterone/progestogen is given per cycle. A small proportion are revealing an inactive or atrophic endometrium. Up to 50% of biopsies in cases on continuous combined HT contain minimal tissue for pathological analysis: this correlates well with an atrophic endometrium with no appreciable pathology. Of the 50% with more substantial material, approximately one half presents endometrial atrophy, and one half are showing weak secretory features [94]. The Romanian analysis shows that after complete non-oral route of HT, the proliferative rate and secretory changes were more frequent in the first year, and

atrophy was after oral HT. The analysis regarding endometrial stroma has revealed two important aspects to be discussed:

