Comparison of pathological, radiological, and prognostic features between cellular schwannoma and non-cellular...

To investigate the differences of pathological, radiological, and prognostic features between cellular schwannoma (CS) and non-cellular schwannoma (NCS).

CT and MRI images of 24 patients with CSs and 30 patients with NCSs were reviewed retrospectively. Clinico-pathological characteristics of CSs and NCSs and tumor radiological features including location, shape, size, border, cystic-solid components, hemorrhage, calcification, bone remodeling, pattern of CT/MRI precontrast scan, degree of enhancement, target sign, and tumor vessels were recorded. Statistical analyses were performed with Chi square or Fisher's exact test, independent sample t test, and logistic regression analysis to compare the differences between CSs and NCSs.

Four CSs showed mitotic activity, which was not found in the NCS group (P = 0.034). The CS group showed higher MIB-1 index than that in the NCS group (P = 0.002). Two patients with CS presented with tumor recurrence. Compared to NCSs, CSs were often located in spinal area (P = 0.028) and irregular (P = 0.013) with larger size (P = 0.005). Target sign, a common finding in NCSs (7/22, 31.8 %), was not seen in CSs (P = 0.014). The tumor vessels were only seen in CS group (4/22, 18.2 %; P = 0.027). Regression analysis revealed that location (P = 0.048) and size (P = 0.012) were independent indicators in differentiating CSs from NCSs.

CS is a rare subtype of schwannoma with some significant radiological features including a predilection for the spinal area, irregular shape, large tumor size, absent target sign, tumor vessels, and potential risk of recurrence. Location and size of the schwannomas were the most useful indicators in differentiating CSs from NCSs.