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

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• 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

References

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