Imaging of Ancient Schwannoma

TLDR

The authors surveyed clinical symptoms, radiologic, and pathologic features of ancient schwannoma in seven patients (mean age 62) between 1998 and 2003. Ancient schwannomas can reach up to 14 cm, show characteristic contrast enhancement of peridegenerative areas and capsules on MRI/CT, display bone scintigraphy uptake but not gallium‑67 citrate uptake, and differ from typical schwannoma and neurofibroma patterns, aiding differentiation from malignancy.

Abstract

We surveyed the clinical symptoms and radiologic features of ancient schwannoma, a rare variant of schwannoma characterized by degenerative changes.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.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.The characteristic clinical and radiologic findings of ancient schwannoma should make it possible to differentiate it from malignant tumors.