P16(INK4a) overexpression independent of Human Papilloma Virus (HPV) infection in rare subtypes of endometrial carcinomas.
In the current study, we evaluated p16 expression in rare subtypes of endometrial carcinomas, whose HPV status has been previously examined in order to establish the role of this protein in their pathogenesis. These rare subtypes of endometrial carcinomas are primary squamous endometrial carcinoma (ESCC), endometrial mucinous microglandular adenocarcinoma (EMMA), and endometrial transitional cell carcinoma (ETCC). All tissues, obtained at the time of hysterectomy, were fixed in 10% phosphate-buffered formalin and embedded in paraffin. Serial sections were made for hematoxylin and eosin staining and for immunohistochemistry. Although a previous PCR study has demonstrated that none of these neoplasms showed any signal for HPV DNA, these malignancies did display immunoreactivity for P16(INK4a). In ESCC, P16(INK4a) immunoreactivity was diffuse in 100% of neoplastic cells. In two cases of EMMA, positivity for P16INK4a was zonal. In ETCC, scattered cells were positive for P16INK4a protein. These findings suggest that alteration of p16 could play an etiologic role, without any association to HPV infections, in these rare endometrial carcinomas. However, in our view, other cases of these rare malignancies should be investigated in order to confirm this hypothesis.
Giordano
Giovanna
G
Department of Pathology and Laboratory Medicine, Section of Pathology, Parma University, Viale A. Gramsci, 14, 43100 Parma, Italy. giovanna.giordano@unipr.it
Azzoni
Cinzia
C
D'Adda
Tiziana
T
Merisio
Carla
C
D002288:Adenocarcinoma, Mucinous / Q000378:metabolism / Q000821:virology; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000821:virology; D002295:Carcinoma, Transitional Cell / Q000378:metabolism / Q000821:virology; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000096:biosynthesis*; D016889:Endometrial Neoplasms / Q000378:metabolism* / Q000821:virology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D027383:Papillomaviridae; D030361:Papillomavirus Infections / Q000150:complications*; D016133:Polymerase Chain Reaction
D019941:Cyclin-Dependent Kinase Inhibitor p16