Presentation
Right flank pain. Chronic and worsening. Normal inflammatory markers.
Patient Data
There is erosion of the inferior margin of the right 11th rib. The erosion has a well-defined sclerotic margin.
These findings are suggestive of a slow growing soft tissue tumor likely related to the intercostal neurovascular bundle.
The finding is on the 'edge of the film' and is subtle but there, particularly when compared to the left side.
Otherwise the chest x-ray is normal.
MRI study reveals a 4.0 cm mass in the soft tissues underlying the inferior aspect of the right 11th rib.
The spherical lesion is fairly homgenous and of intermediate signal, however there is a higher signal center. This suggests central cystic and fatty degeneration.
There are no further lesions in the imaged chest and upper abdomen.
Annotated image shows the fascicular sign: coronal T2, fat-saturated sequence reveals small, circular, low-signal intensity area surrounded by a background of mild hyperintensity.
Case Discussion
The findings on the chest x-ray are suggestive of a slow growing soft tissue tumor, likely related to the intercostal neurovascular bundle. The findings are subtle but present, particularly when compared to the left side.
The MRI findings of an isolated, well circumscribed spherical high signal lesion in the intercostal soft tissues, raises the possibility of a schwannoma.
Closer, magnified T2 imaging reveals a subtle fascicular sign and illustrates the value of magnified inspection of lesions. Moreover, the high signal center is suggestive of central cystic and fatty degeneration, which is common is schwannomas.
The patient has a strong family history of NF3 / schwannomatosis.