Chromogranin A by IHC-12376 - Technical only, 12379 - Technical & interpretation

Test info

Chromogranin A by IHC
12376 - Technical only, 12379 - Technical & interpretation

All IHC stains will include a positive control tissue

  • Used in a panel for neuroendocrine tumors
  • Best used in combination with other neuroendocrine markers such as Synaptophysin, Leu-7 (and possibly NSE)
  • Neuroendocrine tumors with only a few secretory granules may show a false negative reactivity
  • 23-78% of small cell lung carcinomas stain positive with chromogranin.1 (usually focal and weak staining)



Submit a formalin-fixed, paraffin-embedded tissue


Formalin-fixed, paraffin-embedded (FFPE) tissue block


FFPE tissue section mounted on a charged, unstained slide


Ambient (preferred)

  • Unlabeled/mislabeled block
  • Insufficient tissue
  • Slides broken beyond repair


AHL - Immunohistochemistry
Mo - Fr
1 - 2 days

Immunohistochemical staining and microscopic examination

Clinical and Interpretive info


If requested, an interpretive report will be provided



  • Chromogranin is an acidic protein found in the secretory granules of neuroendocrine cells
  • 3 types exist; A, B, C: Type A is the most ubiquitous and is the type this antibody recognizes
  • Chromogranin stains most normal and neoplastic endocrine tissue containing secretory granules, including the following:
    o Adrenal medulla
    o Pheochromocytomas
    o Paragangliomas
    o Endocrine neoplasms of the pancreas
    o Medullary thyroid carcinoma
    o Normal C-cells of the thyroid
    o Normal endocrine cells of the GI tract
    o Carcinoids
    o Normal parathyroid
    o Normal anterior pituitary
    o Merkel cell tumors of skin
    o Small cell CA of the lung
  • The amount of staining is usually proportional to the number of secretory granules present.

Staining pattern

  • Cytoplasmic based staining; granular


  1. Guinee et. al.; The Spectrum of Immunohistochemical Staining of Small-Cell Lung Carcinoma in Specimens from Transbronchial and Open-Lung biopsies; American Journal of Clinical Pathology, 102:406-414, 1994


88342 - 1st stain
88341 - each additional stain