FIGURE 1.

Tumor specimens obtained from bony tissue. A: Failed genotyping of a core needle biopsy from a glenoid metastasis. Although the specimen demonstrates high tumor cellularity, the extensive infiltration of bone trabeculae necessitated decacification prior to processing. Subsequent genotyping from a second specimen (cell block from a transbronchial FNA) successfully demonstrated a deletion mutation in exon 19 of the EGFR gene. B: Successful tumor genotyping of a core needle biopsy from a L3 spinal metastasis in a 64 year old female never smoker. The poorly differentiated adenocarcinoma (5 and 9 o’clock) is seen in a background of fibrosis with only rare bony trabeculae, thus decalcification was unnecessary for specimen processing. Compare the appearance of the calcified bone trabeculae with the decalcified osteoid in part A; the former demonstrates shattering or fracturing artifact, and had a more basophilic hue. C: Successfully genotyped core needle biopsy specimen of a sacral metastasis. The poorly differentiated adenocarcinoma can be seen extending into the periosseous soft tissues (adipose tissue and skeletal muscle on the right). The lack of calcified tissue in this bony metastasis obviated the need for decalcification, leading to successful tumor genotyping. All images were taken at 200x original magnification, hematoxylin and eosin stain.