Stains
Ki67 / MIB1

Author: Nat Pernick, M.D. (see Authors page)

Revised: 10 November 2015, last major update October 2012

Copyright: (c) 2002-2015, PathologyOutlines.com, Inc.

PubMed Search: MIBI [title]

Cite this page: Ki67. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/stainski67.html. Accessed December 5th, 2016.
Definition / General
  • A marker of cell proliferation first described in 1983 (Int J Cancer 1983;31:13)
  • Name derived from Kiel, Germany (city of origin) and the clone number in the 96 well plate (Wikipedia)
  • Labile, non-histone nuclear protein expressed in G1, S, G2 and M phases of cell cycle, then rapidly catabolized at end of M phase and not detectable in G0 and early G1 cells (J Cell Physiol 2000;182:311)
  • MIB1 is the IgG1 antibody against Ki67 for formalin-fixed, paraffin embedded tissue
Uses by Pathologists
Micro Images

Images hosted on PathOut server:

Missing Image

Skin, symplastic glomus tumor, toe

Missing Image

Small bowel, malignant GIST

Missing Image

Tonsil, normal, c/o Leica Microsystems

Missing Image Missing Image

Urethra, clear cell adenocarcinoma

Missing Image Missing Image

Lymph node, normal

Missing Image

Lymph node, Burkitt lymphoma

Missing Image

Cervix, adenocarcinoma in situ, endocervix



Images hosted on Other servers:

Missing Image Missing Image

Breast, hemangioma vs high grade angiosarcoma

Missing Image Missing Image

Breast, invasive carcinoma, basal-like subtype with high Ki67 index

Missing Image

LUMA tumor

Missing Image

Colon, adenomatous vs nonadenomatous polyps

Missing Image

Kidney, malignant solitary fibrous tumor

Missing Image

Lymph node, diffuse large B cell lymphoma

Missing Image

Pancreas, islet cell tumors

Missing Image Missing Image

Uterus (left to right), mid-proliferative endometrium, day 17 endometrium



Nature images:

Missing Image

Breast, invasive carcinoma

Missing Image

Skin, Spitz nevus

Missing Image

Skin, nevi vs melanoma

Missing Image

Lymph node, Burkitt lymphoma

Missing Image

Breast, phyllodes tumors



Positive Staining - Normal
  • Placenta, early (cytotrophoblast: 25-50%, intermediate villous trophoblast: >90%)
Positive Staining - Disease
  • High grade neoplasms, including Burkitt lymphoma, carcinoma in situ, invasive carcinomas (many), malignant phyllodes tumor (breast), sarcomas (many)
  • Conjunctival Spitz nevus and squamous papilloma are Ki67+
Negative Staining
  • Most benign or reactive lesions; nevi