CASE 10213 Published on 29.08.2012

Undifferentiated endometrial sarcoma: MR imaging findings with pathologic correlation

Section

Genital (female) imaging

Case Type

Clinical Cases

Authors

Alexandra Ntorkou1, Athina C. Tsili1, Maria I. Argyropoulou1, Anna Gousia2, Konstantinos Tsampoulas1.

1) Department of Clinical Radiology; 2) Department of Pathology; University Hospital of Ioannina, Greece.

University Hospital of Ioannina, Clinical Radiology, Dept. Of Radiology
Pl. Patgis 2 45332 Ioannina, Greece
Email:a_tsili@yahoo.gr
Patient

72 years, female

Categories
Area of Interest Genital / Reproductive system female ; Imaging Technique MR-Diffusion/Perfusion, MR
Clinical History
A 72 year-old female patient presented with lower abdominal cramping pain and recurrent vaginal bleeding. The patient was referred for MRI examination of the pelvis.
Imaging Findings
A markedly enlarged uterus was detected on MRI, with a voluminous inhomogeneous mass, replacing the endometrial cavity and extending into most of the myometrial thickness and into the cervix (Figures 1-3). The tumour was heterogeneous, mainly isointense to normal myometrium on both T1 and T2-weighted images, with hyperintense areas on T2-weighted sequences. After gadolinium administration, the neoplasm enhanced heterogeneously (Figure 3). DW images showed significant restricted diffusion by the neoplasm, confirming the diagnosis of malignancy (Figure 2). Neither tumour extension into the adjacent structures nor pelvic lymphadenopathy was revealed. Differential diagnosis included advanced endometrial carcinoma and uterine mesenchymal malignancies. The presence of a bulky endometrial mass with a predominant myometrial component was more suggestive of a uterine sarcoma.
Patient underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy. Histology reported undifferentiated endometrial sarcoma (FIGO Ib, Figure 4).
Discussion
Background
Uterine sarcomas are a heterogeneous group of rare neoplasms, arising from the myometrium or from connective tissue elements within the endometrium [1-12]. Histologic subtypes include endometrial stromal sarcomas, leiomyosarcomas and undifferentiated uterine sarcomas. In current terminology, endometrial stromal sarcoma (ESS) replaces the term low-grade ESS and undifferentiated uterine sarcoma (UUS) replaces the term high-grade ESS. USSs are a very rare subtype of uterine sarcomas, representing less than 5% of all uterine sarcomas [8, 9]. They typically occur in postmenopausal women and show an aggressive clinical course, with a great tendency to local recurrence and even greater to distant spread. Prognosis is poor, closely related to the stage of the disease at the diagnosis [8, 9].
Imaging Perspective
Based on imaging findings the preoperative diagnosis of uterine sarcomas and the distinction among the various histologic subtypes is challenging [2-6]. Sahdev et al. described two patterns on MRI, including a large, heterogeneous pelvic mass and an invasive endometrial mass, indistinguishable from endometrial carcinoma [2]. Among sarcomas, leiomyosarcomas are more likely to present as massive uterine enlargement, whereas endometrial stromal sarcomas, as in this case, usually present as large endometrial polypoid masses, with deep myometrial invasion.
Despite histological heterogeneity, uterine sarcomas often appear with signal intensity similar or lower than normal myometrium on T1-weighted images and scattered hyperintense areas, the latter corresponding to haemorrhagic foci on histology. The neoplasms are heterogeneous, with intermediate or low signal intensity on T2-weighted sequences, and hyperintense areas, corresponding to cystic necrosis on pathology. These features were met in our case. Presence of hypointense bands in areas of myometrial involvement on T2-weighted images has been described as an important imaging finding for low-grade ESS, corresponding to preserved myometrial bundles, separated by tumour cells on pathology. Another characteristic finding of endometrial stromal sarcoma is the continuous extension into the surrounding tissues, including the fallopian tubes, the uterine ligaments or the ovaries, reflecting vascular and lymphatic involvement [2-6].
Tumour hyperintensity on T2-weighted images, heterogeneous enhancement after gadolinium administration and restricted diffusion represent significant imaging findings in differentiating uterine sarcomas from other uterine masses, especially benign leiomyomas [12-14].
Differential Diagnosis List
Undifferentiated endometrial sarcoma.
Endometrial carcinoma
Lymphoma
Leiomyoma with Secondary degeneration
Adenomyosis
Intravenous leiomyomatosis
Final Diagnosis
Undifferentiated endometrial sarcoma.
Case information
URL: https://www.eurorad.org/case/10213
DOI: 10.1594/EURORAD/CASE.10213
ISSN: 1563-4086

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