J Korean Soc Med Ultrasound.  1999 Sep;18(3):221-226.

US Findings of Neurilemmoma of the Extremities: Pathologic Correlation

• Choi JO
• An JH
• Cho KH
• Park BH
• Hwang MS
• Lee JK
• Kim DS

Abstract

PURPOSE: To describe the sonographic features of peripheral neurilemmomas and to compare them with histopathologic findings.
MATERIALS and METHODS
Ten cases of the neurilemmoma confirmed by pathology were evaluated, retropectively. We analyzed the size, shape, margin, echogenicity, homogeneity, the existence of peripheral nerves, and the distribution of vascularity of five cases with a color-coded Doppler study. We compared sonographic features with the pathologic findings including gross and microscopic features.
RESULTS
The tumors were round and oval shaped, and all tumors showed low echogenic mass with posterior enhancement and distinct margins. The arising nerve was found in five cases. Seven cases showed inhomogeneous echogenicity. All of 5 cases showed vascularity on echogenic area or boundary portion between the hyperechoic and hypoechoic area of the mass on the color-coded Doppler study. Some areas of hemorrhage and myxoid degeneration were described in seven cases on pathologic paper. On microscopy, all specimen were composed of cellular Antoni A tissue and myxoid Antoni B tissue, and more larger specimen showed several cystic degeneration and hemorrhagic foci in the mass. It was difficult to correlate the exact foci on microscopic feature with sonographic feature due to unclear the section slice.
CONCLUSION
Sonographic characteristics of peripheral neurilemmoma include low echogenicity, posterior enhancement, distinct margin, inhomogeneous internal echo, and suspended nerve strings. Inhomogeneous internal echo may be attributed to the variable cellularity, cystic change, and focal hemorrhage of the tumors.

MeSH Terms

Extremities*
Hemorrhage
Microscopy
Neurilemmoma*
Pathology
Peripheral Nerves
Ultrasonography