CD44 is a family of transmembrane glycoproteins which mediate cell-extracellular matrix interactions. They are involved in cell surface binding to hyaluronate and interactions with cytoskeleton-related molecules including actin and ankyrin. It is therefore expressed on the basolateral surfaces of myoepithelial cells of ducts and acini. It has also been implicated in lymphocyte activation and homing and tumour invasion. The gene is located on chromosome 11 and contains at least 20 exons, 10 of which can be alternatively spliced to create a variety (at least 25) of isoforms10.

Antibodies are effective on paraffin-embedded tissue14.

Immunohistochemical expression

The CD 44 family of glycoproteins exist in a number of isoforms:

Diagnostic utility




Attanoos 19972



Afify 19989



Filie 1998 (on cytological specimens)15



Cury 20003



Ordonez 200016



Harper 20017



Comin 20018



Attanoos 200117

not studied


Roberts 200118



Attanoos 200219



Ordonez 200320




39% (154/391)

66% (401/605)

Staining is reportedly weaker in post mortem specimens that in the corresponding ante mortem specimens from the same patients13.


1Bohm JP et al. Reduced CD44 standard expression is associated iwth tumour recurrence and unfavourable outcome in differentiated thyroid carcinoma. J Pathol 2000;192:321-327.

2Attanoos, R. L., Webb, R., Gibbs, A. R. CD44H expression in reactive mesothelium, pleural mesothelioma and pulmonary adenocarcinoma. Histopathology 1997;30:260-3.

3Cury, P. M.,et al. Value of the mesothelium-associated antibodies thrombomodulin, cytokeratin 5/6, calretinin, and CD44H in distinguishing epithelioid pleural mesothelioma from adenocarcinoma metastatic to the pleura. Mod Pathol 2000;13:107-12.

4S Ramasami et al. Expression of CD44v6 but not E-cadherin or ß-catenin influences prognosis in primary pulmonary adenocarcinoma. J Pathol 2000;192:427-432.

5L Setala et al. Expression of CD44 and its variant isoform v3 has no prognostic value in gastric cancer. Histopathology 2001; 38: 13-20.

6 Daniel L et al. CD44s and CD44v6 expression in localised T1-T2 conventional renal cell carcinomas. J Pathol 2001;193:345-349.

7Harper CM. Evaluation of a commercially available immunohistochemical diagnostic panel for malignant mesothelioma. J Pathol 2001:193(suppl):39A.

8Comin, C. E., Novelli, L., Boddi, V., Paglierani, M., Dini, S. Calretinin, thrombomodulin, CEA, and CD15: a useful combination of immunohistochemical markers for differentiating pleural epithelial mesothelioma from peripheral pulmonary adenocarcinoma. Hum Pathol 2001;32:529-536.

9Afify. Applied Immunohistochemistry 1998;6:11-15.

10McKenney, J. K., Desai, S., Cohen, C., Amin, M. B. Discriminatory immunohistochemical staining of urothelial carcinoma in situ and non-neoplastic urothelium: an analysis of cytokeratin 20, p53, and CD44 antigens. Am J Surg Pathol 2001;25:1074-1078.

11Poncelet, C., Walker, F., Madelenat, P., Bringuier, A. F., Scoazec, J. Y., Feldmann, G., Darai, E. Expression of CD44 standard and isoforms V3 and V6 in uterine smooth muscle tumors: a possible diagnostic tool for the diagnosis of leiomyosarcoma. Human Pathol ,2 001;32:1190-1196.

12Rioux-Leclercq, N., Epstein, J. I., Bansard, J. Y., Turlin, B., Patard, J. J., Manunta, A., Chan, T., Ramee, M. P., Lobel, B., Moulinoux, J. P. Clinical significance of cell proliferation, microvessel density, and CD44 adhesion molecule expression in renal cell carcinoma. Human Pathol 2001;32:1209-1215.

13Roberts, F., McCall, A. E., Burnett, R. A. Malignant mesothelioma: a comparison of biopsy and postmortem material by light microscopy and immunohistochemistry. J Clin Pathol 2001;54:766-70.

14Leong A S-Y, Cooper K and Leong FJ W-M. Manual of diagnostic antibodies for immunohistology. 2nd edition, 2003

15Filie, A. C., A. Abati, et al. (1998). "Hyaluronate binding probe and CD44 in the differential diagnosis of malignant effusions: disappointing results in cytology material." Diagn Cytopathol 18(6): 473-4.

16Ordonez, N. G. (2000). "Value of thyroid transcription factor-1, E-cadherin, BG8, WT1, and CD44S immunostaining in distinguishing epithelial pleural mesothelioma from pulmonary and nonpulmonary adenocarcinoma." Am J Surg Pathol 24(4): 598-606.

17Attanoos, R. L., R. Webb, et al. (2001). "Malignant epithelioid mesothelioma: anti-mesothelial marker expression correlates with histological pattern." Histopathology 39(6): 584-8.

18Roberts, F., C. M. Harper, et al. (2001). "Immunohistochemical analysis still has a limited role in the diagnosis of malignant mesothelioma. A study of thirteen antibodies." Am J Clin Pathol 116(2): 253-62.

19Attanoos, R. L., R. Webb, et al. (2002). "Value of mesothelial and epithelial antibodies in distinguishing diffuse peritoneal mesothelioma in females from serous papillary carcinoma of the ovary and peritoneum." Histopathology 40(3): 237-44.

20Ordonez, N. G. (2003). "The immunohistochemical diagnosis of mesothelioma: a comparative study of epithelioid mesothelioma and lung adenocarcinoma." Am J Surg Pathol 27(8): 1031-51.


This page last revised 6.5.2002.

©SMUHT/PW Bishop