Bcl-2 overexpression in basaloid proliferations overlying dermatofibromas and basal cell carcinomas.
Basaloid proliferations overlying dermatofibromas resembling superficial basal cell carcinomas have been interpreted both as reactive/regressive and frankly malignant. Basal cell carcinoma is a slow-growing tumour, which so far has been regarded as an actively proliferating lesion with a high apoptotic activity. We examined immunohistochemically 6,dermatofibromas with overlying simple hyperplasia, 12 dermatofibromas with overlying basaloid proliferations, and 24 basal cell carcinomas for expression of Ki-67 protein, and bcl-2 protein. The Ki-67 labelling index represents an estimate of proliferative activity. Bcl-2 protein suppresses apoptosis. The Ki-67 labelling indexes of basaloid proliferations, basal cell carcinomas, and normal epidermis were similar (11-15%, p < 0.05, Mann-Whitney test). Bcl-2 protein was expressed in all cells of basaloid proliferations, similar to the expression pattern in basal cell carcinomas. We suggest that basaloid proliferations overlying dermatofibromas might have achieved a phenotype that equals an early stage of BCC carcinogenesis.
Rossen
K
K
Department of Pathology, Gentofte University Hospital, Hellerup, Denmark.
Haerslev
T
T
Hou-Jensen
K
K
Jacobsen
G K
GK
D002280:Basal Cell Carcinoma / Q000378:metabolism*; D004817:Epidermis / Q000378:metabolism; D018219:Histiocytoma, Benign Fibrous / Q000378:metabolism*; D006801:Humans; D006965:Hyperplasia / Q000378:metabolism; D007124:Immunoenzyme Techniques; D019394:Ki-67 Antigen / Q000096:biosynthesis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D012878:Skin Neoplasms / Q000378:metabolism*
D019394:Ki-67 Antigen; D019253:Proto-Oncogene Proteins c-bcl-2