[P63 protein in the diagnosis of breast tubular carcinoma].
OBJECTIVE
To study and compare the expression of p63 protein and smooth muscle actin in breast tubular carcinoma (TC) and its main differential diagnoses, radial scar (RS)/complex sclerosing lesion (CSL).


METHODS
Immunohistochemistry techniques were used to search for p63 protein and smooth muscle actin antibodies in 10 patients with TC and fifteen with RS/CSL.


RESULTS
Myoepythelial cells were diffusely positive for both actin and p63 protein with a cytoplasmic (actin) or nuclear (p63) pattern in all patients with RS/CSL. Inversely, all TC were negative for p63. Actin antibodies failed to label myoepithelial cells in TC, but both vessels and stromal myoblasts were actin-positive, creating difficult interpretation situations. By contrast, p63 was consistently negative in these structures.


CONCLUSIONS
For the differential diagnosis between TG and CR/LSC, smooth muscle actin and p63 protein demonstrate equivalent sensitivity for the detection of myoepithelial cells. However, the nuclear pattern of p63 labeling gives a "cleaner" stain. In addition, p63 enables distinction between myoepithelial cells and myofibroblasts/vascular smooth muscle cells, offering increased specificity.
Noël
Jean-Christophe
JC
Service d'Anatomie Pathologique, Clinique de Gynécopathologie et de Sénologie, Hôpital Universitaire Erasme, Université Libre de Bruxelles (ULB), Route de Lennik 808, 1070 Bruxelles, Belgium. jenoel@ulb.ac.be
Fayt
Isabelle
I
Fernandez-Aguilar
Sergio
S
D000230:Adenocarcinoma / Q000737:chemistry* / Q000175:diagnosis*; D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000737:chemistry* / Q000175:diagnosis*; D003598:Cytoskeletal Proteins / Q000032:analysis*; D004268:DNA-Binding Proteins; D003937:Diagnosis, Differential; D005260:Female; D016147:Genes, Tumor Suppressor; D006801:Humans; D008875:Middle Aged; D009124:Muscle Proteins / Q000032:analysis*; D010750:Phosphoproteins / Q000032:analysis*; D015534:Trans-Activators / Q000032:analysis*; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins
D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; D009124:Muscle Proteins; D010750:Phosphoproteins; C470306:Smooth muscle protein, human; C115051:TP63 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins