Lab: Special Histochemical Stains and Immunohistochemical Stains

Special histochemical and immunohistochemical stains are covered when necessary to produce a complete, actionable diagnosis that will be used by the treating physician and when the pathologist documents the medical necessity, specific blocks, markers and results. Routine pre-orders, reflex templates prior to H&E review, standing orders for broad marker panels (e.g., Ki‑67 or EGFR for all breast cancers), excessive non‑actionable stains, and chemosensitivity panels are not covered; certain organ‑specific exceptions (renal, liver, neuromuscular, select GI, prostate, lung, renal neoplasms, bone marrow) and specific predictive tests (ER/PR/HER2 for breast and gastric; Ki‑67 for a defined high‑risk breast subgroup) are explicitly addressed and require documentation.

"Special histochemical stains and/or IHC are medically necessary when they are required to produce a complete and accurate diagnosis that will be reported to and used by the treating physician to gu..."