SCLC, tumor markers
• 3 main groups: Neural, Epithelial, Neuroendocrine • Epithelial: virtually all SCLCs are immunoreactive for Keratin and Epithelial Membrane Antigen • 1 or more markers of Neural/Neuroendocrine differentiation found in approx. 75 % of SCLCs
SCLC, tumor markers
– Leads to expression of dopa decarboxylase, calcitonin, neuron-specific enolase, chromogranin A, CD-56 (a neural cell adhesion molecule) gastrin releasing peptide and insulin-like growth hormone – Occasionally patients produce antibodies that crossreact with both the SCLC cells and the CNS cerebellar degeneration syndromes – SCLC cells can produce a number of polypeptide hormones including ACTH and Vasopressin
• Cells are approx. 2 X’s the size of normal lymphocytes
SCLC, pathology