Abstract
Papillary immature metaplasia (PIM) is a distinctive exophytic lesion of the uterine
cervix and shares some histologic and cytologic features with ordinary squamous
metaplasia (SM), atypical immature squamous metaplasia (AIM), high-grade squamous
intraepithelial neoplasia (HSIL) and papillary squamous cell carcinoma
(PSC). PIM has been suggested to be a subset of condyloma associated with
low-risk type human papilloma virus (HPV), however, the etiologic role of HPV
and biologic behavior of the disease are still elusive. We compared the clinical
and histopathological findings, immunohistochemical expression of Ki-67 and
p53 protein, and HPV typing of 5 cases of PIM with SM (n=9), HSIL (n=6), and
PSC (n=4) to know the helpful features for the differential diagnosis. Histologically,
all 5 cases showed a papillary proliferation of immature metaplastic cells
involving the proximal transformation zone and endocervix. On HPV typing by
polymerase chain reaction-restriction fragment length polymorphism, 2 out of 5
PIM were confirmed to have HPV 6 or HPV 11, while 2 out of 4 PSC were proved
having HPV 31 and HPV 16 each. Ki-67 labeling index and mitotic index of PIM
were significantly lower than those of HSIL or PSC. There were no significant
differences of Ki-67 labeling index and mitotic index between PIM and SM. The
expression of p53 varied among the groups and thus it was not helpful for the
differential diagnosis.