9560/0 Schwannoma, NOS



Definitions

Peripheral nerves and autonomic nervous system
ICD-O-3 topography code: C47

/span>chwannoma is a benign nerve sheath tumour that is typically encapsulated and composed entirely of well-differentiated neoplastic Schwann cells. The vast majority of schwannomas follow a benign clinical course (WHO grade I) 1
 
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (Eds.)
WHO Classification of Tumours of the Central Nervous System.
4th Edition
International Agency for Research on Cancer: Lyon 2007



. Multiple schwannomas are associated with neurofibromatosis type II (NF2) or schwannomatosis .

Histological variants:

> ntional or cellular type. The vast majority arise in skin or subcutaneous tissue of an extremity, head and neck, or trunk. Cranial and spinal nerves are usually spared. There is a low association with schwannomatosis and NF2 , but not NF1.

Melanotic schwannoma>



Tumours of the central nervous system
ICD-O-3 topography code: C70, C71 and C72

/span>chwannoma is a benign nerve sheath tumour that is typically encapsulated and composed entirely of well-differentiated neoplastic Schwann cells. The vast majority of schwannomas follow a benign clinical course (WHO grade I)
3
 
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (Eds.)
WHO Classification of Tumours of the Central Nervous System.
4th Edition
International Agency for Research on Cancer: Lyon 2007



. Multiple schwannomas are associated with neurofibromatosis type II (NF2) or schwannomatosis .

Histological variants:

> ntional or cellular type. The vast majority arise in skin or subcutaneous tissue of an extremity, head and neck, or trunk. Cranial and spinal nerves are usually spared. There is a low association with schwannomatosis and NF2 , but not NF1.

Melanotic schwannoma>



Stomach
ICD-O-3 topography code: C16

/span>chwannoma is a benign nerve sheath tumour that is typically encapsulated and composed entirely of well-differentiated neoplastic Schwann cells. The vast majority of schwannomas follow a benign clinical course (WHO grade I)
5
 
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (Eds.)
WHO Classification of Tumours of the Central Nervous System.
4th Edition
International Agency for Research on Cancer: Lyon 2007



. Multiple schwannomas are associated with neurofibromatosis type II (NF2) OMIM or schwannomatosis OMIM .

Histological variants:

> st majority arise in skin or subcutaneous tissue of an extremity, head and neck, or trunk. Cranial and spinal nerves are usually spared. There is a low association with schwannomatosis OMIM or neurofibromatosis type II (NF2) OMIM , but not NF1.

Melanotic schwannoma>



Hypopharynx, Larynx and Trachea
ICD-O-3 topography code: C13, C32, C33

/span>chwannoma is a benign nerve sheath tumour that is typically encapsulated and composed entirely of well-differentiated neoplastic Schwann cells. The vast majority of schwannomas follow a benign clinical course (WHO grade I)
7
 
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (Eds.)
WHO Classification of Tumours of the Central Nervous System.
4th Edition
International Agency for Research on Cancer: Lyon 2007



. Multiple schwannomas are associated with neurofibromatosis type II (NF2) or schwannomatosis .

Histological variants:

> ntional or cellular type. The vast majority arise in skin or subcutaneous tissue of an extremity, head and neck, or trunk. Cranial and spinal nerves are usually spared. There is a low association with schwannomatosis and NF2 , but not NF1.

Melanotic schwannoma>



Nasal cavity and Sinuses
ICD-O-3 topography code: C30-C31

/span>chwannoma is a benign nerve sheath tumour that is typically encapsulated and composed entirely of well-differentiated neoplastic Schwann cells. The vast majority of schwannomas follow a benign clinical course (WHO grade I)
9
 
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (Eds.)
WHO Classification of Tumours of the Central Nervous System.
4th Edition
International Agency for Research on Cancer: Lyon 2007



. Multiple schwannomas are associated with neurofibromatosis type II (NF2) or schwannomatosis .

Histological variants:

> entional or cellular type. The vast majority arise in skin or subcutaneous tissue of an extremity, head and neck, or trunk. Cranial and spinal nerves are usually spared. There is a low association with schwannomatosis and NF2 , but not NF1.

Melanotic schwannoma>



Breast
ICD-O-3 topography code: C50

Schwannoma is a benign nerve sheath tumour that is typically encapsulated and composed entirely of well-differentiated neoplastic Schwann cells.

Neurofibroma and schwannoma of the breast are discussed together under, Benign peripheral nerve-sheath tumours.






Adrenal gland
ICD-O-3 topography code: C74

/span>i>Schwannoma is a benign nerve sheath tumour that is typically encapsulated and composed entirely of well-differentiated neoplastic Schwann cells. The vast majority of schwannomas follow a benign clinical course (WHO grade I)
13
 
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (Eds.)
WHO Classification of Tumours of the Central Nervous System.
4th Edition
International Agency for Research on Cancer: Lyon 2007



. Multiple schwannomas are associated with neurofibromatosis type II (NF2) or schwannomatosis .

Histological variants:

> or cellular type. The vast majority arise in skin or subcutaneous tissue of an extremity, head and neck, or trunk. Cranial and spinal nerves are usually spared. There is a low association with schwannomatosis and NF2 , but not NF1.

Melanotic schwannoma>



Kidney
ICD-O-3 topography code: C64

/span>chwannoma is a benign nerve sheath tumour that is typically encapsulated and composed entirely of well-differentiated neoplastic Schwann cells. The vast majority of schwannomas follow a benign clinical course (WHO grade I)
15
 
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (Eds.)
WHO Classification of Tumours of the Central Nervous System.
4th Edition
International Agency for Research on Cancer: Lyon 2007



. Multiple schwannomas are associated with neurofibromatosis type II (NF2) or schwannomatosis .

Histological variants:

> ntional or cellular type. The vast majority arise in skin or subcutaneous tissue of an extremity, head and neck, or trunk. Cranial and spinal nerves are usually spared. There is a low association with schwannomatosis and NF2 , but not NF1.

Melanotic schwannoma>



Colon and rectum
ICD-O-3 topography code: C18-C20

Schwannoma is a benign nerve sheath tumour that is typically encapsulated and composed entirely of well-differentiated neoplastic Schwann cells. The vast majority of schwannomas follow a benign clinical course (WHO grade I)
17
 
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (Eds.)
WHO Classification of Tumours of the Central Nervous System.
4th Edition
International Agency for Research on Cancer: Lyon 2007



. Multiple schwannomas are associated with neurofibromatosis type II (NF2) OMIM or schwannomatosis OMIM .

Schwannoma of the colon and rectum
Schwannomas similar to those in the stomach occur in the colon and rectum, usually in older adults. Presentations include gastrointestinal bleeding and a polypoid, obstructing, intraluminal mass. The histological features of these tumours are similar to those in the stomach, with the typical features including peritumoral lymphoid cuff and microtrabecular architecture. Small mucosal nerve sheath tumours occur in the colon and rectum. The designation ?mucosal Schwann cell hamartoma? has also been used for apparently similar lesions. These tumours are clinically indolent and are not associated with neurofibromatosis type 1 (NF1)
18
Click to access Pubmed
Gibson JA, Hornick JL (2009)
Mucosal Schwann cell "hamartoma": clinicopathologic study of 26 neural colorectal polyps distinct from neurofibromas and mucosal neuromas.
Am J Surg Pathol 33: 781-7



19
Click to access Pubmed
Miettinen M, Shekitka KM, Sobin LH (2001)
Schwannomas in the colon and rectum: a clinicopathologic and immunohistochemical study of 20 cases.
Am J Surg Pathol 25: 846-55



20
 
Bosman FT, Carneiro F, Hruban RH, Theise ND (Eds.)
WHO Classification of Tumours of the Digestive System.
4th Edition
International Agency for Research on Cancer: Lyon 2010



.



Bone
ICD-O-3 topography code: C40-C41

/span>chwannoma is a benign nerve sheath tumour that is typically encapsulated and composed entirely of well-differentiated neoplastic Schwann cells. The vast majority of schwannomas follow a benign clinical course (WHO grade I)
21
 
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (Eds.)
WHO Classification of Tumours of the Central Nervous System.
4th Edition
International Agency for Research on Cancer: Lyon 2007



. Multiple schwannomas are associated with neurofibromatosis type II (NF2) or schwannomatosis .

Histological variants:

> ntional or cellular type. The vast majority arise in skin or subcutaneous tissue of an extremity, head and neck, or trunk. Cranial and spinal nerves are usually spared. There is a low association with schwannomatosis and NF2 , but not NF1.

Melanotic schwannoma>



Connective, subcutaneous and other soft tissues
ICD-O-3 topography code: C49

/span>chwannoma is a benign nerve sheath tumour that is typically encapsulated and composed entirely of well-differentiated neoplastic Schwann cells. The vast majority of schwannomas follow a benign clinical course (WHO grade I)
23
 
Louis DN, Ohgaki H, Wiestler OD, Cavenee WK (Eds.)
WHO Classification of Tumours of the Central Nervous System.
4th Edition
International Agency for Research on Cancer: Lyon 2007



. Multiple schwannomas are associated with neurofibromatosis type II (NF2) or schwannomatosis .

Histological variants:

> ntional or cellular type. The vast majority arise in skin or subcutaneous tissue of an extremity, head and neck, or trunk. Cranial and spinal nerves are usually spared. There is a low association with schwannomatosis and NF2 , but not NF1.

Melanotic schwannoma>