Presentation
Right sided flank pain. CT KUB requested for ? renal calculi.
Patient Data
There is an ill-defined soft tissue denisty mass lying immediately anterior to the distal sacrum in the pre-sacral fat. The mass infiltrates the pre-sacral fat.
There is a tiny focus of calcification contained within.
There is no definite direct communication with the rectum and there is no associated lymphnode enlargement.
The MRI further confirms the CT appearances of an enhancing mass in the presacral fat.
As with the CT study, there is no associated lymph node enlargement.
The MRI further confirms the CT appearances of an enhancing mass in the persacral fat (arrow).
On close inspection, the mass infiltrates the ventral sacral foramina.
Pathology report:
MICROSCOPIC DESCRIPTION: Histology shows cores of a lesion composed of bland spindle cells with wavy nuclei. Numerous ganglion cells are also noted. Cores of surrounding fibrofatty
tissue and skeletal muscle are also present. There is no atypia, mitoses, or necrosis. No undifferentiated areas are noted. The morphological features in these cores are consistent with a ganglioneuroma.
HISTOLOGICAL DIAGNOSIS: Presacral mass core biopsy: Morphological features consistent with a ganglioneuroma.
Case Discussion
The differential diagnosis for presacral masses includes a liposarcoma, which was considered the chief differential in this case.
Close inspection reveals the invasion of the ventral sacral foramina. This a reliable sign to identify neurogenic origin tumors and shifts the differential diagnosis away from liposarcoma or an inflammatory lesion such as tuberculosis.