Imaging characteristics of parasymphyseal pubic cartilaginous cysts

To review the imaging of parasymphyseal pubic cartilaginous cysts (PPCCs).

An IRB-approved retrospective review was performed to identify pathologically and image-confirmed cases of PPCC. Anatomic location relative to the pubic symphysis, lesion size, CT/MRI characteristics, and imaging characteristics from additional modalities, when available, were recorded. Histology, if present, was reviewed. Clinical data was recorded from electronic health records.

Forty-nine cases of PPCCs were identified, four histologically confirmed cases and forty-five with characteristic imaging features (32F, 17 M, mean age 70.8 ± 9.9 years). Mean lesion dimensions were 17 ± 8 mm anteroposterior, 18 ± 7 mm transverse, and 14 ± 7 mm craniocaudal. The most common lesion location was superior and posterior to the pubic symphysis, seen in 20 (41%) of 49 cases. PPCCs typical appearance on CT was a rim-enhancing, complex cystic mass with mean internal density of 45 ± 16 HU. PPCCs typical appearance on MRI was a rim-enhancing, T1 hypointense, heterogeneously T2 hyperintense lesion.

PPCCs are benign degenerative cystic lesions originating from the pubic symphysis occurring most commonly in older women. Recognition of the characteristic location and imaging features of PPCCs can help prevent misdiagnosis and unnecessary intervention.