Stains
Calcitonin

Author: Meenakshi Gupta, M.D. (see Authors page)

Revised: 26 January 2017, last major update December 2015

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Calcitonin [title]

Cite this page: Calcitonin. PathologyOutlines.com website. http://pathologyoutlines.com/topic/stainscalcitonin.html. Accessed October 24th, 2017.
Definition / general
  • Calcitonin (thyrocalcitonin) is a 32 amino acid linear polypeptide hormone (molecular weight 3,421Kd) that participates in calcium and phosphorus metabolism
  • It is formed by the proteolytic cleavage of a larger pre-propeptide, which is a product of the CALC1 gene (CALC)
  • In humans, it is primarily produced by the parafollicular cells (C cells) of the thyroid
  • Other tissues such as the lungs and intestinal tract can also synthesize calcitonin
  • The calcitonin receptor protein has been shown to be a member of the seven transmembrane G protein coupled receptor family, which is coupled by G5 to adenylate cyclase and thereby to the generation of CAMP in target cells
Case reports
Uses by pathologists
  • As a marker for medullary thyroid carcinoma (MTC), especially when facing histologic subtypes such as the follicular, papillary or encapsulated variants that can pose diagnostic difficulties with follicular cell–derived carcinomas and paraganglioma (Arch Pathol Lab Med 2008;132:359)
  • Although highly specific, calcitonin staining may be patchy in medullary carcinomas and 5% of these tumors may be negative for this marker
    • In tumors with no staining and still suspected to be MTC, calcitonin and calcitonin gene–related peptide mRNA can be demonstrated by in situ hybridization (Arch Pathol Lab Med 2010;134:207)
  • To evaluate for C cell hyperplasia associated with familial MTC
    • High grade neuroendocrine tumors can also stain with calcitonin, and metastatic lesions can be misinterpreted as having arisen in the thyroid (Adv Anat Pathol 2004;11:202)
  • Immunoreactive calcitonin along with calmodulin has been stained and quantitated in solitary endocrine cells which are increased in number and staining intensity in cystic fibrosis lung when compared to COPD and normal lungs
    • The calcitonin and calmodulin may be associated with increased calcium in pulmonary secretions leading to selective colonization of the lung by a limited number of pathogenic bacteria and enhanced pulmonary infection (Chest 1986;89:327)
Microscopic (histologic) images
Images hosted on PathOut server, courtesy of Andrey Bychkov, M.D., Ph.D.:

Cluster of C cells

Pericapillary location of C cells

Heavy background in the
immediate stroma and follicles



Images hosted on other servers:

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Thyroid

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Single endocrine cell

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Prostate

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HGPIN

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Bone metastasis