Uterine Carcinoma



Uterine Carcinoma


Todd M. Blodgett, MD

Alex Ryan, MD

Sanjay Paidisetty, BS





Key Facts


Imaging Findings



  • Primary endometrial cancer: Thickened endometrium on CT with intense FDG activity on PET, correlating with mass


  • MR/CT used to evaluate disease extension and provide information for treatment planning, ± ultrasound


  • FDG PET for staging, restaging, early detection, evaluating response to therapy


  • Signs of metastatic disease on PET/CT: Lymphadenopathy with increased FDG, abdominal/distant metastases


  • PET/CT useful for anatomic and functional localization of sites of recurrence


  • Significant nonmalignant uptake in younger patients who are menstruating


  • Sensitivity of PET alone (87%) or plus MR or CT (91%) is higher than MR or CT alone (˜ 67% in overall lesion detection)


  • PET most useful for detecting distant metastases


Top Differential Diagnoses



  • Uterine Leiomyoma


  • Endometrial Hyperplasia


  • Endometrial Polyp


  • Cervical Cancer


  • Endometrial Sarcoma


Diagnostic Checklist



  • MR or CT for extent of primary tumor


  • PET/CT for optimal staging


  • Note benign causes of increased FDG activity in endometrium (e.g., menstruation)






Graphic shows a representation of uterine body carcinoma image.






Axial fused PET/CT shows an enlarged uterus with circumferential FDG activity image and central necrosis image in this patient with uterine leiomyosarcoma.


TERMINOLOGY


Abbreviations and Synonyms



  • Endometrial carcinoma, uterine sarcoma, uterine carcinosarcoma, leiomyosarcoma


Definitions



  • Malignancy of uterine endometrium or uterine body



    • Most common type is endometrioid adenocarcinoma


IMAGING FINDINGS


General Features



  • Best diagnostic clue



    • Primary endometrial cancer



      • Thickened endometrium on CT


      • Intense FDG activity on PET corresponding to lesion


    • FDG uptake in metastatic sites



      • Lymphadenopathy


      • Abdominal and distant metastases


  • Location



    • Usually glandular component of superior endometrium



      • May spread within endo-/myometrium and from fundus toward isthmus and cervix


      • May arise within an endometrial polyp


Imaging Recommendations



  • Best imaging tool



    • CT/MR



      • Evaluate disease extension


      • Provide information for treatment planning


      • Detect lymph node metastases; 18-66% sensitivity and 73-99% specificity


      • Limited in recurrent disease due to anatomic distortion 2° surgery and radiation


    • FDG PET



      • For staging, restaging, early detection, and evaluating response to therapy


      • Incorporation of FDG PET into post-therapy surveillance shown to influence treatment in up to 20% of patients


      • Particularly useful for asymptomatic disease


    • PET/CT useful for anatomic and functional localization of sites of recurrence




  • Protocol advice



    • Oral contrast agent for CT



      • Helps better delineate normal bowel activity


      • Demonstrates pathologic intra-abdominal activity (peritoneal implants)


    • IV contrast



      • Differentiates small lymph nodes from vessels, intestine, or the ureter


      • Correctly detects small liver metastases, small peritoneal dissemination, and local recurrence at the vagina


CT Findings



  • Inconsistent depiction of endometrium and endometrial thickness


  • Findings associated with endometrial carcinoma are nonspecific and similar to other conditions


  • Uterine cancer and normal endometrium are often indistinguishable on nonenhanced CT



    • May see diffuse thickening, discrete mass, or polypoid mass within endometrial cavity


    • Cavity may be expanded with fluid


    • Mass may be of uniform or heterogeneous attenuation


    • Usually poorly enhancing relative to myometrium



      • Variable areas of contrast enhancement


  • IV contrast also aids in evaluating local invasion by increasing conspicuity of tumor


  • Invasion of myometrium suggested by irregular tumor-myometrium border



    • CT limited in ability to delineate deep myometrial invasion and cervical involvement


  • CT reasonably sensitive for lymphadenopathy and distant metastases



    • Size cutoff for suspicion of malignancy > 8-10 mm in short axis


MR Findings



  • T1WI



    • Endometrium and myometrium have similar signal intensity and cannot readily be distinguished


  • T2WI



    • Endometrium appears as central zone of high signal intensity


  • Myometrium depicted as zone of low signal intensity at its inner aspect and a wider zone of intermediate signal intensity at its outer aspect


  • Endometrial thickness varies in menstruating women from 4 mm in early proliferative phase to 13 mm in late secretory phase


Nuclear Medicine Findings

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Sep 22, 2016 | Posted by in MAGNETIC RESONANCE IMAGING | Comments Off on Uterine Carcinoma

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