CoChat
Sign Up
Cited by 7Endometriosis Research and TreatmentEndometrial and Cervical Cancer TreatmentsOvarian cancer diagnosis and treatment

Malignancies Associated with Extraovarian Endometriosis: A Literature Review

Open access
Inoue, Naoki, Hirakawa, Takashi, Mitsushita, Junji, Kitahara, Yoshikazu, Iwase, Akira·2021·Endocrines
DOI 10.3390/endocrines2030024
Open this paper in CoChat — free accountOpen PDF

Abstract

Endometriosis-associated ovarian malignancies have been well documented. Although these malignancies also occur as extraovarian lesions, little is known about them. Thus, this literature review aimed to further explore these rarely experienced tumors. A total of 257 published cases between April 1990 and April 2020 were found using PubMed, and 212 cases were included in the analysis considering Sampson’s criteria and the history of endometriosis. We classified these cases as follows: intestine, abdominal scar, vagina and vulva, peritoneum and deep endometriosis, urinary tract, uterine cervix, and others. Age of patients, history of endometriosis, types of past hormonal therapy, symptoms, histological types, and treatment were identified. The most common tumor site was the intestine. Endometrioid carcinoma was the dominant histological type. Contrary to the ovary, clear cell carcinoma was rare in extraovarian sites. On the other hand, clear cell carcinoma represented the largest number of abdominal scars. This difference may help us to understand the development of endometriosis-related malignancies. Hormonal treatment was mentioned in 67 cases and estrogen replacement therapy in 33 cases. Although risks of estrogen therapy are still controversial, the highly differentiated histological types and hormone-dependent characteristics of endometriosis-associated malignancy should be considered. Physicians should be careful about estrogen monotherapy after hysterectomy and long-term hormone replacement therapy in patients with a history of endometriosis.

AI snapshot

Written from the paper’s full text.

TL;DR

This literature review summarizes published cases of malignancy arising in extraovarian endometriosis, finding that the intestine was the most common site and endometrioid carcinoma the dominant histology. Clear cell carcinoma was rare at most extraovarian sites but was the most common histology in abdominal scar lesions.

Key findings

  • The review included 213 cases from 158 reports (16 case series and 127 case reports); sites were intestine (73), abdominal scar (44), vagina/vulva (33), peritoneum/deep endometriosis (30), urinary tract (17), uterine cervix (4), and other sites (12).
  • Overall mean age at diagnosis was 51.9 ± 11.0 years; 81 patients (38.0%) had a history of endometriosis. Among 119 patients with hormonal treatment mentioned, 68 had received hormonal therapy and 33 had undergone estrogen replacement therapy.
  • The most common histological types overall were endometrioid carcinoma (80 cases), clear cell carcinoma (56), endometrioid stromal sarcoma (27), adenosarcoma (14), mixed epithelial carcinoma (10), low malignant potential epithelial tumor (7), other carcinomas (7), carcinosarcoma (6), and peritoneal malignant mesothelioma (6).
  • Site-specific patterns differed: intestine was dominated by endometrioid carcinoma (36/73) with few clear cell carcinomas (3/73), whereas abdominal scar was dominated by clear cell carcinoma (28/44); vagina/vulva had endometrioid carcinoma in 17/33 and clear cell carcinoma in 9/33.

Methods

  • PubMed was searched from April 1990 to April 2020 using terms for endometriosis/extraovarian endometriosis, various anatomic sites, and cancer/carcinoma/sarcoma/malignant transformation; reference lists were also manually searched.
  • Cases were included if they met Sampson’s criteria for coexisting endometriosis or had a history of endometriosis and a histological type consistent with endometriosis-related malignancy; cases were classified by localization.
  • Data extracted included patient age, history of endometriosis, past hormonal therapy, symptoms, histology, and treatment.

Limitations

  • The authors state that non-English studies were excluded, only PubMed plus manual search was used, and no large population-based studies were included because of rarity, limiting data on prognosis and prevalence.
  • The authors also state that many cases did not describe details of hormonal therapy, so they could not conclude risk occurrence, and that causality or epidemiological proportions are difficult to estimate from this study.
  • Evident from the text: the review relies on case reports and case series, with likely publication and reporting bias and incomplete data across variables.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.3390/endocrines2030024

Cites

107 of 109 references verified0 citation errors · 2 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 47 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    In urinary tract cases, the most common histological type was clear cell carcinoma and endometrioid carcinoma (six cases each).

    “The most common histological type was EC and CCC in six cases, followed by AS in two cases, and ESS, MEC and others (mucinous carcinoma) in one case.”
    Quote in the paperNot a substantial claim
  • Findingown data

    ESS was found in 15% (12 cases) of intestinal cases.

    “ESS is a malignant mesenchymal neoplasm resembling proliferative-type endometrial stroma outside the uterus and was found in 15% (12 cases) of intestinal cases in this literature review.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Most abdominal scar tumors occurred in a cesarean section scar (37/44 cases).

    “Most of these tumors occurred in a cesarean section scar (37/44 cases).”
    Quote in the paperNot a substantial claim
  • Findingown data

    10 of 17 urinary tract cases (58.8%) had a history of gynecological surgery.

    “In this review, 10 of 17 cases (58.8%) had a history of gynecological surgery which was thought to be a risk factor.”
    Quote in the paperNot a substantial claim
  • Findingnone given

    Endometrioid carcinoma accounted for 71% (17/24) of vagina and vulva lesions.

    “The result that endometrioid carcinoma accounted for 71% (17/24) of this lesion was similar to that in the intestine.”
    Quote in the paperSubstantial claim
  • May combine two claims. 21
  • Classified as probably not a substantial claim. 22
  • The quote only partly states this claim. 1

  • May combine two claims.

    Findingnone given

    Five out of eight vulva lesions occurred in an episiotomy scar, and four of them had clear cell carcinomas.

    “Five out of eight cases of vulva lesions occurred in an episiotomy scar, and four of them had clear cell carcinomas.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In intestinal cases, the most common histological type was endometrioid carcinoma (36 cases), followed by endometrioid stromal sarcoma (12 cases).

    “The most common histological types were EC in 36 cases followed by ESS in 12 cases, AS and LMP in 6 cases, CS and MEC in 4 cases, CCC in 3 cases, and others (serous carcinoma) in 2 cases.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In this review, estrogen monotherapy was administered in 33 cases (27.7%), including OC and hormone replacement therapy in 46 cases (38.7%).

    “In this review, 119 patients were mentioned in relation to the presence or absence of hormone therapy.Estrogen monotherapy was administered in 33 cases (27.7%), including OC and hormone replacement therapy in 46 cases (38.7%).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In uterine cervix cases, clear cell carcinoma was seen in two cases, followed by endometrioid carcinoma and ESS in one case each.

    “Regarding histological type, CCC was seen in two cases, followed by EC and ESS in one case.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In other sites, the most common histological type was clear cell carcinoma (5 cases), followed by endometrioid carcinoma and ESS (3 cases each).

    “The most common histological type was CCC in five cases (inguinal, two; diaphragm, one; liver, one; umbilicus, one), EC in three cases (chest wall, one; diaphragm, one; umbilicus, one), ESS in three cases (liver, one; omentum, one; sciatic nerve, one), and AS in one case (omentum, one).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    In intestinal cases, clear cell carcinoma was less common (3 cases).

    “The most common histological types were EC in 36 cases followed by ESS in 12 cases, AS and LMP in 6 cases, CS and MEC in 4 cases, CCC in 3 cases, and others (serous carcinoma) in 2 cases.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In peritoneum and deep endometriosis cases, the most common histological type was endometrioid carcinoma (10 cases), followed by peritoneal malignant mesothelioma (6 cases).

    “The most common histological type was EC in 10 cases followed by PMM in 6 cases, ESS in 5 cases, CCC and AS in 3 cases, and CS, LMP, and MEC in 1 case.”
    Quote in the paperNot a substantial claim

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    A total of 258 cases were identified from 158 reports, and 213 cases were included in the analysis.

    “A total of 158 reports were identified, including 19 case series and 147 case reports.Out of the identified 258 cases, 45 cases were excluded as follows:”
    • Also stated in: § 3. Results · plain
      “Finally, 213 cases (16 case series and 127 case reports) were included and classified as the intestine (73 cases); abdominal scar (44 cases); vagina and vulva (33 cases); peritoneum and deep endometriosis (30 cases); urinary tract (17 cases); uterine cervix (4 cases); and other sites (12 cases).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The published cases identified through PubMed and manual reference search represent the available evidence on extraovarian endometriosis-associated malignancies.

  • May combine two claims.

    Findingown data

    The 213 included cases were classified by site: intestine (73), abdominal scar (44), vagina and vulva (33), peritoneum and deep endometriosis (30), urinary tract (17), uterine cervix (4), and other sites (12).

    “Finally, 213 cases (16 case series and 127 case reports) were included and classified as the intestine (73 cases); abdominal scar (44 cases); vagina and vulva (33 cases); peritoneum and deep endometriosis (30 cases); urinary tract (17 cases); uterine cervix (4 cases); and other sites (12 cases).”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: The site classification categories are mutually exclusive and exhaustive.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingnone given

    Two other uterine cervix cases had adenomyosis.

    “Two other cases also had adenomyosis.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Out of 119 patients where hormonal treatment was mentioned, 68 had received hormonal therapy and 33 had undergone estrogen replacement therapy.

    “Out of 119 patients where hormonal treatment was mentioned, 68 had received hormonal therapy and 33 had undergone estrogen replacement therapy (Table 2).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In abdominal scar cases, the most common histological type was clear cell carcinoma (28 cases), followed by endometrioid carcinoma (7 cases).

    “The most common histological type was CCC in 28 cases, followed by EC in 7 cases, MEC in 4 cases, and others in 3 cases (2 serous carcinoma and 1 Müllerian carcinoma).CS and ESS were seen in one case each.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In vagina and vulva cases, the most common histological type was endometrioid carcinoma (17 cases), followed by clear cell carcinoma (9 cases).

    “The most common histological type was EC in 17 cases, followed by CCC in 9 cases, ESS in 4 cases, AS in 2 cases, and others (serous carcinoma) in 1 case.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Findingnone given

    In this study, many sarcoma cases were included, such as CS, EES, and AS, which accounted for 22% of the cases.

    “In this study, many sarcoma cases were included, such as CS, EES, and AS, which accounted for 22% of the cases.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    The search was performed by A.I. and the reports were mainly checked by N.I.

    “A.I. performed the search for the reports.N.I.mainly checked the reports.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Mandai et al. reported a nationwide study of cancer in patients with less common/rare site endometriosis; the coexistence rate of malignancy was 0.79% and was more rare compared to in the ovary.

    “Mandai et al. reported a nationwide study of cancer in patients with less common/rare site endometriosis.The coexistence rate of malignancy was 0.79% and was more rare compared to in the ovary [20].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] Mandai, 2020, Cancers associated with extraovarian endometriosis at less common/rare sites: A nationwide survey in Japan, J. Obs. Gynaecol. Res. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Approximately 20% of cases of endometriosis occur as extraovarian endometriosis.

    “Approximately 20% of cases of endometriosis occur as extraovarian endometriosis [18,19].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [18] Heaps, 1990, Malignant neoplasms arising in endometriosis, Obs. Gynecol.

      Not checked in the free run.

    • cites [19] Irvin, 1998, Endometrial stromal sarcoma of the vulva arising in extraovarian endometriosis: A case report and literature review, Gynecol. Oncol. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Mandai et al. noted that the histologic type of the tumor might differ according to the site of origin.

    “In addition, they noted that the histologic type of the tumor might differ according to the site of origin [20].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] Mandai, 2020, Cancers associated with extraovarian endometriosis at less common/rare sites: A nationwide survey in Japan, J. Obs. Gynaecol. Res. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Inclusion and exclusion of cases were discussed by the authors until a consensus was reached.

    “Inclusion and exclusion of cases were discussed by the authors until a consensus was reached.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Pearce et al. summarized 13 case-control studies and reported the highest odds ratio of 3.05 for clear cell carcinoma, followed by LG-serous (2.11) and endometrioid carcinoma (2.04) in patients with endometriosis.

    “Pearce et al. summarized 13 case-control studies and reported the highest odds ratio of 3.05 for clear cell carcinoma, followed by LG-serous (2.11) and endometrioid carcinoma (2.04) in patients with endometriosis [9].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [9] Pearce, 2012, Association between endometriosis and risk of histological subtypes of ovarian cancer: A pooled analysis of case-control studies, Lancet Oncol. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Progestin supplementation could theoretically prevent growth of estrogen-dependent tumors.

    “Heaps et al. described that progestin supplementation could theoretically prevent growth of estrogen-dependent tumors [18].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [18] Heaps, 1990, Malignant neoplasms arising in endometriosis, Obs. Gynecol.

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The most common site in Mandai et al. was the intestine and the most common histological type was endometrioid carcinoma, which was different from those of ovarian origins.

    “The most common site was the intestine and the most common histological type was endometrioid carcinoma, which was different from those of ovarian origins.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] Mandai, 2020, Cancers associated with extraovarian endometriosis at less common/rare sites: A nationwide survey in Japan, J. Obs. Gynaecol. Res. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The transitional zone is seen in only 36-42% of cases and is optional.

    “However, the transitional zone is seen in only 36-42% cases and is optional [7].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [7] Benoit, 2006, Malignant extraovarian endometriosis: A review, Eur. J. Surg. Oncol. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Kobayashi et al. conducted a prospective cohort study of 6398 cases of ovarian endometriosis, which resulted in 46 cases (0.72%) being diagnosed with ovarian carcinoma.

    “Kobayashi et al. conducted a prospective cohort study of 6398 cases of ovarian endometriosis, which resulted in 46 cases (0.72%) being diagnosed with ovarian carcinoma [8].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [8] Kobayashi, 2007, Risk of developing ovarian cancer among women with ovarian endometrioma: A cohort study in Shizuoka, Japan, Int. J. Gynecol. Cancer source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Infertility and delayed menopause increase the risk, while hysterectomy, use of oral contraceptives, and tubal ligation decrease the risk and are common risk factors.

    “Infertility and delayed menopause increase the risk, while hysterectomy, use of oral contraceptives, and tubal ligation decrease the risk and are common risk factors [12].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [12] Vetvicka, 2014, Endometriosis and ovarian cancer, World J. Clin. Oncol. source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductnone given

    For each case, coexistence of endometriosis (Sampson criteria) or a history of endometriosis was confirmed, and cases with histological type consistent with endometriosis-related malignancies were included.

    “Regarding each case, those with coexistence of endometriosis (Sampson criteria) or those with a history of endometriosis were confirmed, and those with histological type consistent with endometriosis-related malignancies were included.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The histological type of a tumor can be reliably classified as consistent with endometriosis-related malignancy from case reports.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductreasoning

    It is difficult to estimate causality or epidemiological proportions from this study.

    “It is difficult to estimate causality or epidemiological proportions from this study, and we hope that further investigations will be conducted.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given

    It has not been clarified whether endometriotic stromal cells derive from normal endometrial stromal cells.

    “On the other hand, there is no clear evidence that EES and AS are caused as a result of EMT, and it has not been clarified whether endometriotic stromal cells derive from normal endometrial stromal cells.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The use of only the PubMed database and the manual search is a limitation to the study.

    “Second, the use of only the PubMed database and the manual search is another limitation to the study.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Most extraovarian endometriosis, such as deep endometriosis and intestinal endometriosis, rarely forms large cysts, unlike in the ovary.

    “As mentioned by Mandai et al., a factor may be that most extraovarian endometriosis, such as deep endometriosis and intestinal endometriosis, rarely form large cysts, unlike in the ovary [20].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] Mandai, 2020, Cancers associated with extraovarian endometriosis at less common/rare sites: A nationwide survey in Japan, J. Obs. Gynaecol. Res. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    The environment of the wound may affect the selection and metabolism of the implanted endometriotic cell.

    “Although it is difficult to clarify the cause of the appearance of histologic differences from intra-abdominal, deep endometriosis and intestinal endometriosis, the environment of the wound may affect the selection and metabolism of the implanted endometriotic cell.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Pokieser et al. considered that the short duration of MPA administration may not have contributed to the prevention of malignant transformation.

    “They considered that the short duration of MPA administration may not have contributed to the prevention of malignant transformation [102].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [102] Pokieser, 2002, Clear cell carcinoma arising in endometriosis of the rectum following progestin therapy, Pathol. Res. Pr. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The rarity of large cyst formation in most extraovarian endometriosis may be a factor in the histological type distribution.

    “As mentioned by Mandai et al., a factor may be that most extraovarian endometriosis, such as deep endometriosis and intestinal endometriosis, rarely form large cysts, unlike in the ovary [20].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] Mandai, 2020, Cancers associated with extraovarian endometriosis at less common/rare sites: A nationwide survey in Japan, J. Obs. Gynaecol. Res. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    EMT has been proposed as a hypothesis for uterine CS.

    “Uterine CS is a homogeneous tumor and epithelialmesenchymal transition (EMT) has been proposed as a hypothesis, and a similar mechanism is assumed for CS derived from endometriosis [107].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [107] Wada, 1997, Molecular evidence that most but not all carcinosarcomas of the uterus are combination tumors, Cancer Res.

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductreasoning

    Our review excludes non-English studies, so racial or regional differences were not considered.

    “First, our review excludes non-English studies, so racial or regional differences were not considered.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given

    Unlike ovarian endometriosis, the accurate incidence of extraovarian endometriosis is uncertain because the prevalence has not been clarified.

    “Unlike ovarian endometriosis, the accurate incidence is uncertain because the prevalence has not been clarified.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Uterine CS is a homogeneous tumor.

    “Uterine CS is a homogeneous tumor and epithelialmesenchymal transition (EMT) has been proposed as a hypothesis, and a similar mechanism is assumed for CS derived from endometriosis [107].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [107] Wada, 1997, Molecular evidence that most but not all carcinosarcomas of the uterus are combination tumors, Cancer Res.

      Not checked in the free run.

37 of 37

  • The paper relies on this without support.

    Malignancies associated with extraovarian endometriosis are poorly understood/little known compared with ovarian endometriosis-associated malignancies.

    “Although these malignancies also occur as extraovarian lesions, little is known about them.”
    “On the other hand, neoplasms arising in extraovarian endometriosis are less known than those in ovarian endometriosis.”

  • The paper relies on this without support.

    The published cases identified through PubMed and manual reference search represent the available evidence on extraovarian endometriosis-associated malignancies.

    “We searched publications and conference abstracts from April 1990 to April 2020 using PubMed using the following search terms (keywords):”
    “We also manually searched reference lists of all original case reports and case series to identify other eligible cases.”

  • The paper relies on this without support.

    The histological type of a tumor can be reliably classified as consistent with endometriosis-related malignancy from case reports.

    “those with histological type consistent with endometriosis-related malignancies were included.”

  • The paper relies on this without support.

    The site classification categories are mutually exclusive and exhaustive.

    “All cases were classified according to localization: intestinal abdominal scar; vagina and vulva; peritoneum and deep endometriosis; urinary tract; uterine cervix; or others.”

  • The authors state this as an assumption.

    A similar EMT mechanism is assumed for CS derived from endometriosis.

    “and a similar mechanism is assumed for CS derived from endometriosis [107].”

  • The paper relies on this without support.

    Endometriosis-associated malignancy is highly differentiated and hormone-dependent.

    “However, considering the high differentiation and hormone-dependency characteristics of endometriosis-associated malignancy, physicians should be careful about estrogen monotherapy after hysterectomy and long-term hormone replacement therapy for patients with a history of endometriosis.”
6 of 6

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Urinary tract subsite counts do not total 17

    Minor

    The 10 bladder and 6 ureter cases account for only 16 of the stated 17 urinary tract cases.

    Reported 17 · recomputed 16

  • Peritoneum and deep endometriosis case count differs

    Minor

    The overall site classification assigns 30 cases to this category, whereas its dedicated section says there were 31.

  • Urinary tract histology is described as both tied and CCC-led

    Minor

    The Results section gives EC and CCC six cases each, but the Discussion identifies CCC alone as the most common type.

  • Report types exceed the stated report total

    Minor

    The stated 19 case series and 147 case reports add to 166 reports, not 158.

    Reported 158 · recomputed 166

  • Different numbers of cases identified

    Minor

    The abstract says 257 cases were found, while the Results section says 258 were identified.

  • Different numbers of cases included

    Minor

    The abstract reports 212 included cases, but the Results section reports 213.

6 of 6

Cites

Flagged first, then by citations

12 of the 121 references couldn’t be matched to a known paper.

Cited by

Sorted by citations

Related

Authors
Inoue, N., Hirakawa, T., Mitsushita, J., Kitahara, Y., & Iwase, A.
Affiliations
  • Gunma University (JP)
  • Maebashi Red Cross Hospital (JP)
Corresponding author
Iwase, Akira
ORCID
Venue
Endocrines
Publisher
MDPI AG
Published
2021-08-11
Volume
2
Issue
3
Pages
251-265
ISSN
2673-396X (ISSN-L)
DOI
10.3390/endocrines2030024
OpenAlex
W3188890797
Semantic Scholar
2b5f4ba4ed3804581642092a9f0a4afd209737cf
Cited by
7
References
121
Citations by year
2026: 3 · 2025: 1 · 2022: 3
FWCI
0.65
Type
journal article
Language
en
Open access
Licence
Locations
  • Endocrines (publishedVersion, cc-by)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Topics
  • Health Sciences › Medicine › Reproductive Medicine › Endometriosis Research and Treatment
  • Health Sciences › Medicine › Obstetrics and Gynecology › Endometrial and Cervical Cancer Treatments
  • Health Sciences › Medicine › Reproductive Medicine › Ovarian cancer diagnosis and treatment
Keywords
endometriosis-associated malignancy, endometrioid carcinoma, clear cell carcinoma, intestinal endometriosis, peritoneal endometriosis, deep infiltrating endometriosis, urinary tract endometriosis, uterine cervix, hormone therapy, estrogen replacement therapy, hysterectomy

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-10.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-10.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review