C-KIT expression in primary cutaneous T-cell lymphomas.
BACKGROUND
Mutations of the stem cell factor receptor C-KIT play a major pathogenetic role in the development of different malignant diseases like human mastocytosis, myeloproliferative disorders, gastrointestinal stromal tumors, acute myelogenous leukemia, and sinonasal lymphomas. Furthermore, the expression of C-KIT has been described in Hodgkin's disease and nodal CD30+ anaplastic large cell lymphomas (ALCLs). As it is possible to inhibit C-KIT by innovative kinase inhibitors like STI571, it may be an attractive target for new therapeutical approaches. Therefore, we screened more than 50 different types of cutaneous T-cell lymphomas (TCLs) for the presence of C-KIT. Immunohistochemical stainings were performed on paraffin-embedded tissue sections using a polyclonal rabbit anti-human C-KIT antibody. Naphtol-ASD-chloroacetate esterase (NASDCE)-control stainings were performed on every positive sample to distinguish C-KIT-positive lymphoma cells from C-KIT-positive mast cells.


RESULTS
We found weak expression of C-KIT in seven of 18 patients with primary cutaneous CD30+ ALCL, two of eight patients with primary cutaneous pleomorphic TCL, six of 18 patients suffering from mycosis fungoides, and three of five patients with Sezary's syndrome. Generally, only a very small population of the lymphoma cells expressed C-KIT. This finding indicates a difference to the systemic variant of CD30+ ALCL. The potential use of C-KIT targeting new therapeutical approaches is therefore discussed critically, because C-KIT expression is very rare in all investigated types of primary cutaneous lymphoma.
Brauns
Tilmann C
TC
Department of Dermatology, University of Essen, Essen, Germany. tilmannbrauns@aol.com
Schultewolter
Thomas
T
Dissemond
Joachim
J
Maschke
Jan
J
Goos
Manfred
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017730:Ki-1 Antigen / Q000378:metabolism; D016403:Lymphoma, Large B-Cell, Diffuse / Q000378:metabolism* / Q000473:pathology; D016410:Lymphoma, T-Cell, Cutaneous / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D019009:Proto-Oncogene Proteins c-kit / Q000096:biosynthesis*; D012878:Skin Neoplasms / Q000378:metabolism* / Q000473:pathology
D014408:Biomarkers, Tumor; D017730:Ki-1 Antigen; D019009:Proto-Oncogene Proteins c-kit