Imaging of ancient schwannoma.
OBJECTIVE
We surveyed the clinical symptoms and radiologic features of ancient schwannoma, a rare variant of schwannoma characterized by degenerative changes.


METHODS
We present the clinical, radiologic, and pathologic features in seven patients with ancient schwannoma (mean age, 62 years; range, 45-80 years) treated at our department between 1998 and 2003.


RESULTS
The most characteristic clinical features were a sign like Tinel's sign and a long interval between the onset of symptoms and surgery (mean interval, 8.3 years). Ancient schwannomas can grow large; the biggest tumor seen in our study was 14 cm long. The highly accurate radiologic assessment made possible with contrast-enhanced MRI and CT scanning showed enhancement at a peridegenerative area and sometimes at a capsule. These findings differ from those of the typical schwannoma and neurofibroma patterns reported to date. Furthermore, bone scintigraphy showed uptake in the tumor, but no accumulation was seen on gallium-67 citrate scintigraphy.


CONCLUSIONS
The characteristic clinical and radiologic findings of ancient schwannoma should make it possible to differentiate it from malignant tumors.
Isobe
Kenichi
K
Department of Orthopedic Surgery, Shinshu University, School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. bechikun@hsp.md.shinshu-u.ac.jp
Shimizu
Tominaga
T
Akahane
Tsutomu
T
Kato
Hiroyuki
H
D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D012983:Soft Tissue Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed