Micro-anatomical variation in cellular proliferation in endometrial adenocarcinoma, and inverse correlation between Ki67 and cytokeratin 7 expression.
OBJECTIVE
To investigate micro-anatomical variations in proliferative activity within uterine endometrioid adenocarcinoma with particular emphasis on tumour areas comprising microcystic, elongated and fragmented ('MELF') glands.


RESULTS
Ki67 immunoreactivity was assessed in 29 low-grade endometrial adenocarcinomas specifically comparing conventional tumour glands and areas exhibiting MELF-type alteration. Furthermore, since Ki67 expression differed between the peripheral and central aspects of larger neoplastic glands, these micro-anatomical compartments were assessed separately using a semiquantitative scoring system. Most MELF-type tumour elements were negative for Ki67 or showed only rare (< 5% cells) positivity. In contrast, peripheral conventional tumour glands showed prominent Ki67 labelling, but this was significantly reduced in central glandular areas. An inverse correlation between Ki67 and cytokeratin (CK) 7 expression was noted in many tumours.


CONCLUSIONS
Endometrial adenocarcinomas show micro-anatomical variations in Ki67 expression and this is often inversely correlated with CK7 immunoreactivity. MELF-type tumour elements show minimal proliferative activity, a finding that initially appears unexpected for areas of purported active invasion. However, an inverse correlation between cell division and local invasion has been demonstrated in other malignancies, notably during epithelial-mesenchymal transition, and this may reflect a reversible alteration in cellular activity during neoplastic progression.
Stewart
Colin J R
CJ
Department of Histopathology, King Edward Memorial Hospital, University of Western Australia, Perth, Australia. colin.stewart@health.wa.gov.au
Crook
Maxine L
ML
Doherty
Dorota A
DA
D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism; D018269:Carcinoma, Endometrioid / Q000378:metabolism* / Q000473:pathology*; D049109:Cell Proliferation; D016889:Endometrial Neoplasms / Q000378:metabolism* / Q000473:pathology*; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053552:Keratin-7 / Q000378:metabolism*; D019394:Ki-67 Antigen / Q000378:metabolism*; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology
D014408:Biomarkers, Tumor; D053552:Keratin-7; D019394:Ki-67 Antigen