Vimentin (57 kDa) is the most ubiquituos intermediate filament protein and the first to be expressed during cell differentiation. All primitive cell types express vimentin but in most non-mesenchymal cells it is replaced by other intermediate filament proteins during differentiation.
Vimentin is expressed in a wide variety of mesenchymal cell types (Fig.1): fibroblasts, endothelial cells etc., and in a number of other cell types derived from mesoderm, e.g., mesothelium and ovarian granulosa cells. However, in non-vascular smooth muscle cells, vimentin is often replaced by desmin. In striated muscle, vimetin is also replaced by desmin. However, during regeneration, vimentin is reexpressed. Cells of the lymfo-haemopoietic system (lymphocytes, macrophages etc.) also express vimentin, sometimes in scarce amounts.
Vimentin is also found in mesoderm derived epithelia, e.g. kidney (Bowman capsule), endometrium and ovary (surface epithelium), in myoepithelial cells (breast, salivary and sweat glands), an in thyroid gland epithelium. In these cell types, as in mesothelial cells, vimentin is coexpressed with cytokeratin. Furthermore, vimentin is detected in many cells from the neural crest. Particularly melanocytes express abundant vimentin. In glial cells vimentin is coexpressed with glial filament acidic protein (GFAP).
Vimentin is present in many different neoplasms but is particulary expressed in those originated from mesenchymal cells. Sarcomas e.g., fibrosarcoma, malignt fibrous histiocytoma, angiosarcoma, and leio- and rhabdomyosarcoma, as well as lymphomas, malignant melanoma and schwannoma, are virtually always vimentin positive (Fig. 2). Mesoderm derived carcinomas like renal cell carcinoma, adrenal cortical carcinoma and adenocarcinomas from endometrium and ovary usually express vimentin. Also thyroid carcinomas are vimentin positive. Any low differentiated or sarcomatoid carcinoma may express some vimentin.
Vimentin is frequently included in the so-called
primary panel (together with CD45, cytokeratin, and S-100 protein): Intense
reaction for vimentin
other intermediate filament proteins is
suggestive of a mesenchymal
tumour or a malignant melanoma. However, in biopsies representing
only a sarcomatoid part of renal cell carcinoma a.o. a strong
positivity for vimentin without cytokeratin expression may be seen.
Tumours like lymphomas and seminomas have the same intermediate
filament profile, but the vimentin expression is usually weaker.
The first commercially available clone for vimentin was V9. One main drawback was the sensitivity of the epitope to formalin fixation. Fixation in formalin for 3 days will in most cases mask the epitope and block the immunoreactivity of V9. For optimal results with V9 it is mandatory to use an efficient pretreatment of formalin fixed specimens. The recommended pretreatment is heat induced epitope retrieval (HIER). Proteolytic digestion is inconsistent due to variations of the fixation times and the type of tissue. Immunostain with V9 without pretreatment can be used for visualization of the uniformity of the fixation in tissue specimens.
The clone 3B4 is less sensitive to formalin fixation. However with usage of HIER as pretreatment there is no difference in the performance of the
antibodies. The clone 3B4 is very sensitive to the pH of the buffer used
for HIER. A change in pH from 6 to 9 will increase the sensitivity 5 - 8
Azumi, N., Battifora, H. The distribution of vimentin and keratin in epithelial and nonepithelial neoplasms. A comprehensive immunohistochemical study on formalin- and alcohol-fixed tumors. Am J Clin Pathol 1987;88:286-96.
Battifora H. Assesment of antigen damage in immunohistochemistry. Am J Clin Pathol. 1991;88:669-671.
Cote RJ, Cordon-Cardo C, Reuter VE, Rosen PP. Immunopathology of adrenal and renal cortical tumors. Coordinated change in antigen expression is associated with neoplastic conversion in the adrenal cortex. Am J Pathol. 1990 May;136(5):1077-84.
Guan XY. Association of Vimentin overexpression and hepatocellular carcinoma metastasis. Oncogene. 2004 Jan 8;23(1):298-302.
Khoury JD, Abrahams NA, Levin HS, MacLennan GT. The utility of epithelial membrane antigen and vimentin in the diagnosis of chromophobe renal cell carcinoma. Ann Diagn Pathol. 2002 Jun;6(3):154-8.
Lang SH, Hyde C, Reid IN, Hitchcock IS, Hart CA, Bryden AA, Villette JM, Stower MJ, Maitland NJ. Enhanced expression of vimentin in motile prostate cell lines and in poorly differentiated and metastatic prostate carcinoma. Prostate. 2002 Sep 1;52(4):253-63.
Niveditha SR, Bajaj P. Vimentin expression
in breast carcinomas. Indian J Pathol Microbiol. 2003 Oct;46(4):579-84.