Pelvic extraperitoneal spaces and lesions: a pictorial review with pathologic correlation

Congress:

ECR 2020

Poster Number:

C-15130

Type:

Educational Exhibit

Keywords:

Genitourinary, Genital / Reproductive system female, Genital / Reproductive system male, Pelvis, CT, MR, Diagnostic procedure, Neoplasia, Pathology, Tissue characterisation, Not applicable, Performed at one institution

Authors:

A. T. Vilares¹, C. Pedrosa Costa¹, M. Silva², A. Silva¹, B. Viamonte¹; ¹Porto/PT, ²204/PT

DOI:

10.26044/ecr2020/C-15130

DOI-Link:

https://dx.doi.org/10.26044/ecr2020/C-15130

Fig. 1: Systematic step-by-step approach to the diagnosis of pelvic extraperitoneal...

Fig. 2: Is the lesion intra or extraperitoneal? (A) Midsagittal T2WI depicts the pelvic...

Fig. 3: Is the lesion intra or extraperitoneal? (A) Enhanced CT depicts internal...

Fig. 4: Is the lesion intra or extraperitoneal? (A) Extraperitoneal tumors displace the...

Learning objectives

To review theanatomyof pelvic extraperitoneal spaces; To describe thespectrum of imaging findingsof pelvic extraperitoneal masses and give adequatepathologic correlationfor the most common entities; To propose asystematic diagnostic approachfor pelvic extraperitoneal lesions based on cross-sectional imaging appearances.

Background

Pelvic extraperitoneal lesions are a relatively uncommon and heterogenous group, comprising both benign and malignant entities arising from various pelvic components and presenting with diverse clinical symptoms. Cross-sectional imaging studies are essential in the work-up of such lesions, confirming both their extraperitoneal origin, as well as allowing their precise location. Although there is significant overlap in the imaging findings, accurate characterization of tumor composition, vascularity and patterns of spread can narrow differential diagnosis. Moreover, recognition of imaging characteristics specific to certain lesions can help guide...

Findings and procedure details

1stSTEP: Is the lesion intra or extraperitoneal? ·The pelvis is divided into extra-peritoneal and intra-peritoneal spaces by the anterior peritoneal reflection line. ·This line can be identified on T2-weighted images in the midsagittal plane as a thin hypointense line of ·The tip of the seminal vesicles in men and uterocervical angle in women are anatomical landmarks for the most inferior point of the peritoneal membrane (Fig.2). ·Analysis of the displacement of normal anatomic structures is one of the most useful tools in determining the origin...

Conclusion

Pelvic extraperitoneal masses comprise a rare and diverse group of lesions with frequently overlapping imaging appearances. A systematic diagnostic approach including: (1) accurate location of the mass; (2) analysis of its relationship with adjacent structures; (3) determination of its composition, pattern of enhancement and pattern of growth; (4) recognition of characteristic imaging features suggesting a specific diagnosis and (5) clinical context integration can increase the diagnostic capability of radiologists and help guide optimal clinical management.

Personal information and conflict of interest

A. T. Vilares; Porto/PT - nothing to disclose C. Pedrosa Costa; Porto/PT - nothing to disclose M. Silva; 204/PT - nothing to disclose A. Silva; Porto/PT - nothing to disclose B. Viamonte; Porto/PT - nothing to disclose

References

Gollub, M., Maas, M., Weiser, M., Beets, G., Goodman, K., Berkers, L. and Beets-Tan, R. (2013). Recognition of the Anterior Peritoneal Reflection at Rectal MRI.American Journal of Roentgenology, 200(1), pp.97-101. Nishino, M., Hayakawa, K., Minami, M., Yamamoto, A., Ueda, H. and Takasu, K. (2003). Primary Retroperitoneal Neoplasms: CT and MR Imaging Findings with Anatomic and Pathologic Diagnostic Clues.RadioGraphics, 23(1), pp.45-57. Rajiah, P., Sinha, R., Cuevas, C., Dubinsky, T., Bush, W. and Kolokythas, O. (2011).Imaging of Uncommon Retroperitoneal Masses.RadioGraphics, 31(4), pp.949-976. O'Connell, A., Duddy, L., Lee,...