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Immunohistochemistry (IHC)
Test Description

Delta-like protein 3 (DLL3) expression is regulated by ASCL1, a transcription factor that is required for proper development of pulmonary neuroendocrine cells. IHC staining is useful in the diagnosis of lung small cell carcinoma (SCLC) and large cell neuroendocrine carcinoma (LCNC) as DLL3 protein is highly expressed in SCLC and other neuroendocrine tumors but has low expression in the majority of normal tissues. The staining pattern is membranous and/or cytoplasmic.

Specimen Requirements
  • A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen type or
  • One (1) unbaked, unstained slide cut at 4-5 microns for H&E staining (required) and two to three (2-3) positively charged unstained slides cut at 3-4 microns for each test/antibody ordered
  • Block and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
Storage and Transportation

Use cold pack for transport. Make sure cold pack is not in direct contact with specimen.

CPT Code(s)*
88360x1, 88342x1, or 88341x1
New York Approved
Level of Service
Stain Only
Turnaround Time

Global: 48 hours, Tech-Only (stain only): 24 hours

  1. Owen DH, Giffin MJ, Bailis JM, et al. DLL3: an emerging target in small cell lung cancer. J Hematol Oncol. 2019;12:61.
  2. Huang RSP, Homes BF, Powell C, et al. Delta-like Protein 3 prevalence in small cell lung cancer and DLL3 (SP347) assay characteristics. Arch Pathol Lab Med. 2019:143(11):1373-1377.
  3. Brcic L, Kuchler C, Eidenhammer S, et al. Comparison of four DLL3 antibodies performance in high grade neuroendocrine lung tumor samples and cell cultures. Diagn Pathol. 2019;14(1):47.

*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.