Age / Sex : 62 / F

Age/Sex:  62/F

Chief complaint:  lower back pain with lower extremity radiating pain (6MA)

1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

* Send Application Answers to In Sook Lee, MD ([email protected])

Courtesy :

schwannoma

Discussion

Findings:

(a) Axial T1WI and T2WI show a 1.8x0.9x1.1 cm sized well-defined dumbbell-shaped mass at L5 central canal and left L5/S1 neural foramen. Mass is both intra- and extradural location. This mass shows low signal intensity on T1WI, heterogeneous high signal intensity on T2WI.

(b) Gadolinium enhanced fat saturated axial and sagittal T1WI shows an intense enhancement of mass.

Diagnosis:

Schwannoma

Discussion:

Schwannomas are well-circumscribed intradural (70-75%) or extradural(15%) or combined intra-extradural (15%) tumors located on peripheral nerves or spinal nerve roots. Location of mass is thoracic> cervical = lumbar. Intradural schwannomas tend to have signal intensity equal to or less than that of the spinal cord on T1-weighted images and mild to marked hyperintensity on T2-weighted images. Nerve sheath tumors in the spine enhance intensely and fairly homogeneously. Focal areas of even greater hyperintensity on T2-weighted images often correspond to cystic portions, whereas hypointensity may represent hemorrhage, dense cellularity, or colIagen deposition. Tumor heterogeneity does not necessarily indicate malignant change. The histology of these neoplasms explains their varied MR appearances. Schwannomas may be composed of both Antoni type A and type B patterns. Antoni type A tissue is rich in cells and is composed of compact bundles of fibrillated cells. Antoni type B tissue is hypocellular and is composed of a loosely textured stroma; in addition, cystic degeneration or xanthomatous change maybe present. Treatment is total surgical resection with involved nerve root sacrifice. Differential diagnosis are neurofibroma, meningioma, and myxopapillary ependymoma.

References:

Intradural schwannomas of the spine: MR findings with emphasis on contrast-enhancement characteristics. AJR 158:1347-1350,June1992

Diagnostic imaging of Spine, Ross.