CD Markers

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

Revised: 9 September 2016, last major update August 2013

Copyright: (c) 2002-2016,, Inc.

Cite this page: CD5. website. Accessed February 22nd, 2018.
Definition / general
  • Important in identification of T cells and most T cell lymphomas, some low grade B cell lymphomas, thymic carcinoma
  • Belongs to ancient scavenger receptor superfamily; at 11q13; binds to CD72
  • CD5+ B cells, which may arise from B-1 cells (subset of B cells) produce "generalist antibodies" using germline (non-mutation) configuration of gene segments - polyreactive low affinity "natural" antibodies (usually IgM) to exogenous antigens (tetanus toxoid, lipopolysaccharide) as well as autoreactive antibodies (Immunol Lett 1993;38:159)
  • First line of defense against antigens; have a low activation threshold; are the only line of defense for those who cannot produce specific antibody
  • May mediate Hepatitis C infection of T cells (J Virol 2012;86:3723)
Clinical features
Uses by pathologists
Microscopic (histologic) images
Scroll to see all images.

Tumors / tissue typically CD5+ - images hosted on PathOut server:

Breast CLL/SLL, by Dr. Julia Braza, Boston, MA (USA)

Eyelid: mantle cell lymphoma

Thymic carcinoma,
nonkeratinizing squamous cell subtype

Tumors / tissue typically CD5+ - images hosted on other servers:

Lymph node: mantle cell lymphoma (fig b)

Tonsil: normal

Thyroid: CASTLE tumor

Various images (quality control)

Tumors / tissue typically CD5+ - image hosted on server:

Lymph node: SLL

Tumors / tissue occasionally / rarely CD5+ - image hosted on PathOut server:

Liver: MALT lymphoma is CD5-

Tumors / tissue occasionally / rarely CD5+ - images hosted on other servers:

Bone marrow:
lymphoplasmacytic lymphoma (fig A)

Breast: florid ductal epithelial hyperplasia and normal ducts with 4C7 antibody

Liver: diffuse
large B cell lymphoma (fig C)

Lymph node: diffuse
large B cell lymphoma

Lymph node: follicular lymphoma: typically CD5 stains only adjacent T cells (left); rarely tumor is CD5+ (right)

Marginal zone lymphomas are rarely CD5+ - images hosted on other servers:

Lung (fig A)

Spleen (fig B)

Positive staining - normal
  • Thymocytes, almost all T cells
  • B cells in fetal spleen and cord blood; B cells in bone marrow (particularly stage 3 hematogones and mature B cells, Am J Clin Pathol 2009;132:733), B cells in peritoneal and pleural cavities, some B cells in mantle zone of spleen and lymph nodes (12% of B cells in peripheral blood, Am J Clin Pathol 2004;121:368)
Positive staining - disease
Negative staining