Benign retroperitoneal schwannoma presenting as colitis: A case report

Table 2 Diagnostic criteria for schwannomatosis[23]

Definite schwannomatosis
1	Two or more pathologically proved schwannomas, plus
2	Lack of radiographic evidence of vestibular schwannoma at age > 18 yr
Presumptive or probable schwannomatosis
1	Two or more pathologically proved schwannomas without symptoms of eighth nerve dysfunction at age > 30 yr or
2	Two or more pathologically proved schwannomas in an anatomically limited distribution (single limb or segment of the spine), without symptoms of eighth nerve dysfunction, at any age