Table 2.

Diagnostic criteria for schwannomatosis 136

Molecular diagnosis

1. Two or more schwannomas or meningiomasa and genetic studies of at least two tumors showing loss of heterozygosity at chromosome 22 and NF2 mutations. The presence of a common SMARCB1 mutation defines SMARCB1‐associated schwannomatosis.

2. One schwannoma or meningiomaa and a germ‐line pathogenic SMARCB1 mutation

Clinical diagnosis

1. Two or more non‐intradermal schwannomas (one with pathological confirmation) and the absence of vestibular schwannoma on thin‐sliced MRIb

2. One schwannoma or meningiomaa and affected first‐degree relative

3. Possible diagnosis if two or more non‐intradermal schwannomas (without pathological confirmation) and chronic pain associated with tumors

Exclusion criteria: germ‐line pathogenic NF2 mutation, fulfill criteria for NF2, first‐degree relative with NF2, schwannomas in radiation field only

^aPathologically confirmed.

^bThese criteria may include some mosaic NF2 patients, and some schwannomatosis patients may have unilateral vestibular schwannomas or multiple meningiomas.

MRI = magnetic resonance imaging; NF2 = neurofibromatosis type 2.