Chapter 8
Reporting of ALK Testing
By Elisabeth Brambilla, Erik Thunnissen, Marileila Varella-Garcia, and Yasushi Yatabe
Consistent with the standard reporting of the molecular pathologic diagnosis of tumors, ALK testing reports should include four sections: preanalytic, analytic, results, and interpretation/conclusion, regardless of the diagnostic method used FISH, IHC, or RT-PCR].
Preanalytic Section
In addition to patient identifiers, this section of a standard report should include a summary of the specimen type and diagnosis, if the molecular diagnosis is not part of the pathologic report being issued at the same time. The following details should be reported. Specimen features • Specimen size and type: surgical resection (lobectomy, pneumonectomy, segmentectomy, wedge), biopsy (bronchial/transbronchial biopsy, core-needle biopsy), FNA for cytology, fluid (pleural, cerebral spinal fluid) • Tissue preservation: snap-frozen (storage temperature) or FFPE • Tissue fixation: the fixation time and duration and the fixative used (only buffered formalin is recommended for FFPE); if tissue has been processed with decalcification solution, this should be documented, as well as the reagent used Tumor histologic diagnosis For adenocarcinoma, the type and subtype should follow the 2011 IASLC/American Thoracic Society/ European Respiratory Society lung adenocarcinoma classification (Travis 2011). Tumors with more than one type should be described as such: adenosquamous carcinoma, combined small cell lung cancer with adenocarcinoma, and large cell neuroendocrine carcinoma (pure or combined with adenocarcinoma). If more than one pattern or histologic type is present in the same tumor, the predominant histologic type in the testing sample should be stated, and if not, the type tested should be documented. Tumor assessment • Estimate of tumor cellularity (percentage of tumor cell nuclei compared with all nuclei present on the section) of the whole section, to obtain an impression of whether the sample has sufficient tumor cells for IHC, FISH, and/or RT-PCR