A schwannoma is a usually benign nerve sheath tumor composed of Schwann cells, which normally produce the insulating myelin sheath covering peripheral nerves. Overview Schwannomas are homogeneous tumors, consisting only of Schwann cells. [Source: Wikipedia ]

OrphaNet reference
Benign schwannoma 
Is A
Nerve sheath tumor
May Cause
Adrenal tumor
Anterior mediastinal lesion
Base of tongue mass
Benign bone neoplasm
Calcified mediastinal mass
Carotid space mass
Cerebellopontine angle lesion
Chest wall lesion
Choroidal mass
Colonic tumor
Cyst-like mandibular lesion
Cystic soft-tissue tumor
Displacement of the thoracic paraspinal line
Erosion of mastoid
Erosion of middle ear
Erosion of tympanic portion of petrous bone
Facial nerve lesion outside the temporal bone
Infratentorial intracranial tumor in a child
Intermuscular soft-tissue tumor
Intratracheal mass
Jugular foramen lesion
Masticator space lesion
Middle cranial fossa lesion
Multifocal soft-tissue tumor
Multiple nerve tumors
Nasopharyngeal extension of intracranial neoplasm
Nasopharyngeal lesion
Neck mass
Oropharyngeal lesion
Paranasal sinus mass
Parapharyngeal space lesion
Paraspinal soft-tissue mass
Posterior fossa lesion
Posterior skull base lesion
Retrobulbar mass
Sacral neoplasm
Salivary gland lesion
Salivary gland neoplasm
Sinonasal lesion
Sinonasal mass with bony remodeling without erosion
Soft-tissue mass with adjacent bone erosion
Soft-tissue neck mass
Soft-tissue tumor in a young adult
Soft-tissue tumor in an older adult
Soft-tissue tumor with associated calcification
Soft-tissue tumor with fluid-fluid level
Solid mass in carotid sheath
Solitary intracranial calcification
Solitary thoracic calcification
Subcutaneous tumor
T1-hypointense intracranial lesion
T1-isointense intracranial lesion
T2-hyperintense intracranial lesion
Trigeminal nerve lesion
Unilateral exophthalmos
Urothelial tumor