Claudins
The claudins are a family of over twenty proteins which are components of the tight junction (Latin claudere, to close). They are found with other components including occludin and junctional adhesion molecule, and interact with scaffold proteins, ZO-1, ZO-2 and ZO-3. The claudins constitutes a variable component, with specific claudins being associated with specific tissues.
Immunohistochemical expression
A number of tumours which form the differential from perineuromas are negative for Claudin-1:
|
|
Claudin-1
|
|
|
perineuroma
|
11/12(staining is membranous: >50% of cells in 7/12 cases, 25-50% of cells in 3/12 cases, <25% of cells in 1/12 cases)1,
22/76(soft tissue perineuromas: 14 cases staining of more than 50% of cells, 3 cases staining of 26-50% of cells, 4 cases staining of 5-25% of cells, 1 case staining of less than 5% of cells.)2
|
|
|
0/71
|
low-grade fibromyxoid sarcoma
|
0/81
|
desmoplastic fibroblastoma
|
0/31
|
fibromatosis
|
0/71
|
|
|
6/9(a significant number of cells, mainly peripheral, with long cytoplasmic processes, thought to be perineural in origin were positive.)1
|
|
|
3/5(capsular cells in three cases and perivascular cells in one case were positive)1
|
| |
Diagnostic utility
-
Claudin-1, with EMA (positive) and S-100 (negative) in the diagnosis of perineuroma.
-
Claudin 18 in combination with annexin 8 has potential for differentiating benign pancreatic epithelium from infiltrating ductal carcinoma of the pancreas3.
References
1 Folpe, A.L., Billings, S.D., McKenney, J.K., Walsh, S.V., Nusrat, A. and Weiss, S.W. Expression of claudin-1, a recently described tight junction-associated protein, distinguishes soft tissue perineurioma from potential mimics. Am J Surg Pathol 2002;26:1620-6.
2 Hornick JL,Fletcher CD. Soft tissue perineurioma: clinicopathologic analysis of 81 cases including those with atypical histologic features. Am J Surg Pathol 2005; 29:845-58
3 Karanjawala ZE, Illei PB, Ashfaq R, et al. New markers of pancreatic cancer identified through differential gene expression analyses: claudin 18 and annexin A8. Am J Surg Pathol 2008; 32:188-96
This page last revised 1.3.2008.
©SMUHT/PW Bishop