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Clinical presentation and imaging of uterine adenosarcoma

TL;DR — The usual presentation is abnormal uterine bleeding and a polypoid endometrial or cervical mass, sometimes protruding through the os (Clement 1990, PMID 2156771; Nathenson 2016, PMID 27718181). MRI, when performed, shows a large polypoid endometrial lesion, often with cystic spaces, hemorrhage, and protrusion into the cervical canal; mean longest diameter 9.3 cm in a 30-case systematic review (Morikawa 2025, PMID 39729099). Those features overlap endometrial polyps and submucosal fibroids. A PubMed search updated 2026-09-01 found no prospective study measuring the sensitivity of MRI, ultrasound, or office biopsy for adenosarcoma against a hysterectomy gold standard. Preoperative pathology “occasionally failed” in Tate’s assembled Japanese series (Tate 2018, PMID 29441675). Imaging therefore has no validated rule-out performance before morcellation.

Clinical presentation

Abnormal vaginal bleeding is the dominant symptom in every clinicopathologic series that records it (Clement 1990, PMID 2156771; Nathenson 2016, PMID 27718181; Friedlander 2014, PMID 25341585). In Morikawa’s imaging review, bleeding was the chief complaint in 96.7% (Morikawa 2025, PMID 39729099). Clement’s 100 patients: enlarged uterus and tissue protruding from the external os were the common pelvic-exam findings; five patients had presented on multiple occasions with “recurrent polyps” (Clement 1990, PMID 2156771). Age at presentation spans adolescence to the ninth decade (Clement 1990, PMID 2156771; Gallardo 2009, PMID 18941402). Cervical primaries skew younger (Yuan 2019, PMID 31139558).

Tamoxifen association is reported at case-report level (Ceylan 2015, PMID 28913077; Soh 2008, PMID 19143068) and is listed by NCI PDQ as a uterine-sarcoma risk factor, not as an adenosarcoma-specific quantified risk (NCI PDQ — "Uterine Sarcoma Treatment", https://www.cancer.gov/types/uterine/patient/uterine-sarcoma-treatment-pdq, accessed 2026-09-01). Do not convert those case reports into an incidence.

What imaging actually shows

Morikawa 2025 is a systematic review of MRI: 25 published cases from 23 articles plus 5 institutional, total 30 (Morikawa 2025, PMID 39729099). Median age 48.5 (range 9–79). Pathological T1 stage in 85.2%; SO in 55.2% of this imaging-selected set (higher than most surgical series — selection). Recurrence 36.4%.

MRI findings in that review:

Feature Frequency / value
Mean longest lesion size 9.3 cm
Uterine-body location 93.1%
Endometrial involvement 96.6%
Polypoid morphology 90.0%
Protrusion into cervical canal 80.8%
Cystic change 96.5%
Hemorrhage (where evaluable) 84.6%
T2 signal vs myometrium high 51.7% / intermediate 48.3%
Contrast enhancement heterogeneous in all
Mean ADC 1.05 × 10⁻³ mm²/s

Harada 2025 compared MRI of adenosarcoma with endometrial polyps and reported that adenosarcomas had larger size, more frequent cystic change, higher DWI signal and lower ADC (Harada 2025, PMID 40210681). That is a retrospective differentiation study, not a screening test, and the abstract does not report sensitivity, specificity, or a pre-specified cut-point validated in a second cohort.

Ultrasound is the usual first test for bleeding and will show a polypoid endometrial mass or an enlarged uterus; no adenosarcoma-specific sonographic sign has been prospectively validated. The imaging literature is almost entirely case reports plus the two papers above.

The fibroid and polyp differential

The clinical trap is that adenosarcoma presents as the same complaint — bleeding, polyp, presumed fibroid — that fills benign gynaecology lists. Occult uterine sarcoma among hysterectomies for presumed leiomyomas was 1 in 278, or 3.60 per 1,000 (95% CI 2.97–4.23), in a Kaiser Permanente cohort of 34,728 leiomyoma hysterectomies; occult leiomyosarcoma 1 in 429, or 2.33 per 1,000 (95% CI 1.83–2.84) (Raine-Bennett 2016, PMID 26646120). That study is about uterine sarcoma as a class, not adenosarcoma. Multinu’s Olmsted County series of 4,232 hysterectomies found unexpected sarcoma in 0.13% (5/3,759) of benign-indication hysterectomies and 0.39% (about 1 in 256) among fibroid hysterectomies; all four unexpected sarcomas among fibroid surgeries were leiomyosarcoma (Multinu 2019, PMID 30447212). Adenosarcoma was not the occult histology in that series.

The implication for adenosarcoma is indirect: the tumour is rare even among occult sarcomas, so a strategy designed around leiomyosarcoma risk will encounter adenosarcoma even less often — and will still miss it when the presentation is a “polyp” rather than a “fibroid.” Tate noted that preoperative radiology and pathology sometimes failed to reach the correct diagnosis (Tate 2018, PMID 29441675). See red flags.

Cervical and pregnancy presentations

Cervical adenosarcoma is a minority of institutional series (Yuan 19/49, Li 7/31) and a larger minority of fertility-sparing case reports, because the patients are younger (Yuan 2019, PMID 31139558; Li 2022, PMID 35005157). Pregnancy-associated cervical adenosarcoma with sarcomatous overgrowth has been described as a case report (Toyoda 2022, PMID 34890128). Case reports are not epidemiology.

Open questions

  • What is the sensitivity of endometrial biopsy, hysteroscopic sampling, and MRI for adenosarcoma in women presenting with polyps? No prospective diagnostic-accuracy estimate was identified in the 2026-09-01 PubMed search. Tate’s qualitative statement of occasional failure is the available evidence (Tate 2018, PMID 29441675).
  • Can ADC or DWI separate adenosarcoma from polyps at a pre-specified threshold in a validation cohort? Harada 2025 is the first dedicated comparison and is not a locked-model validation (Harada 2025, PMID 40210681).

References

  1. Clement PB, Scully RE. Mullerian adenosarcoma of the uterus: a clinicopathologic analysis of 100 cases. Hum Pathol. 1990;21:363-81. PMID 2156771
  2. Nathenson MJ, et al. Uterine Adenosarcoma: a Review. Curr Oncol Rep. 2016;18:68. PMID 27718181
  3. Friedlander ML, et al. GCIG consensus review for mullerian adenosarcoma of the female genital tract. Int J Gynecol Cancer. 2014;24:S78-82. PMID 25341585
  4. Gallardo A, Prat J. Mullerian adenosarcoma: a clinicopathologic and immunohistochemical study of 55 cases. Am J Surg Pathol. 2009;33:278-88. PMID 18941402
  5. Yuan Z, et al. Uterine Adenosarcoma: A Retrospective 12-Year Single-Center Study. Front Oncol. 2019;9:237. PMID 31139558
  6. Li JY, et al. Clinicopathologic characteristics and oncologic outcomes in adenosarcoma of gynecologic sites. Gynecol Oncol Rep. 2022;39:100913. PMID 35005157
  7. Morikawa K, et al. Magnetic resonance imaging features of uterine adenosarcoma: case series and systematic review. Abdom Radiol (NY). 2025;50:3313-3326. PMID 39729099
  8. Harada K, et al. Differentiating uterine adenosarcoma from endometrial polyps: MRI imaging features. Abdom Radiol (NY). 2025;50:5394-5404. PMID 40210681
  9. Tate K, et al. Uterine adenosarcoma in Japan. Asia Pac J Clin Oncol. 2018;14:318-325. PMID 29441675
  10. Raine-Bennett T, et al. Occult Uterine Sarcoma and Leiomyosarcoma: Incidence of and Survival Associated With Morcellation. Obstet Gynecol. 2016;127:29-39. PMID 26646120
  11. Multinu F, et al. Incidence of sarcoma in patients undergoing hysterectomy for benign indications: a population-based study. Am J Obstet Gynecol. 2019;220:179.e1-179.e10. PMID 30447212
  12. Ceylan Y, et al. Mullerian adenosarcoma of the uterus associated with tamoxifen treatment for breast cancer. Turk J Obstet Gynecol. 2015. PMID 28913077
  13. Soh E, et al. Magnetic resonance imaging findings of tamoxifen-associated uterine Müllerian adenosarcoma: a case report. Acta Radiol. 2008. PMID 19143068
  14. Toyoda S, et al. Unusual uterine cervical polypoid mass presenting during pregnancy. Cytopathology. 2022;33:409-411. PMID 34890128