Neurilemmoma (benign schwannoma)

Immunohistochemistry

 

 

retroperitoneal

peripheral

 
 

S-100

90/902

22/222

 

GFAP

104/1152

3/222

AE1/AE3

71/1042

0/222

34bE12

0/232

 

CK1

24/392

 

CK4

0/392

 

CK5/6

0/112

 

CK6

1/242

 

CK7

8/612

Cam 5.2 (CK8/CK18)

0/582

CK10

0/242

CK13

0/152

CK14

3/242

CK15

0/392

CK16

0/392

CK17

0/392

CK18

0/242

CK19

0/352

CK20

0/242

 

HMB45

0/1152

2

     

The positivity for cytokeratins may be due to cross reactivity with GFAP.

Cytogenetics

Monosomy 22, eliminating one of the NF-2 alleles, has been reported in Schwannomas, neurofibromas and perineuromas1.

Differential diagnosis

See the immunohistochemistry of the differential diagnosis of spindle cell tumours of the pleura.

References

Diagnostic Immunohistochemistry edited by Professor D. J. Dabbs, page 72

1 Hahn HP, Fletcher CDM. The role of cytogenetics and molecular genetics in soft tissue tumour diagnosis - a realistic approach. Current Diagnsotic Pathology 2005;11:361-370.

2 Fanburg-Smith JC, Majidi M,Miettinen M. Keratin expression in schwannoma; a study of 115 retroperitoneal and 22 peripheral schwannomas. Mod Pathol 2006; 19:115-21

©SMUHT/PW Bishop