Core needle biopsy wash optimization: Enabling specimen integrity for both cytological and histological evaluation

Background. The recovery of cells after washing core needle biopsies represents an under-utilized approach to extend the diagnostic capacity of these diminutive specimens. Recovery of these cells can be dedicated for molecular studies so that the biopsy itself can be used apropos for its intended purpose, diagnosis. Non-enzymatic and enzymatic reagents have the potential to increase the number of cells dissociating from the tissue core, but can also negatively impact the quality of the tissue itself. Materials and Methods: Three different means (phosphatebuffered saline, a non-enzymatic and an enzymatic solution) were used to wash core needle biopsies. The washed cells were recovered by traditional preparatory methods and evaluated for cellularity and cytomorphology. The postwashed cores were processed by formalin fixation, paraffin embedding and evaluated for integrity and morphological quality. Results: The enzymatic solution damaged both the cytological and tissue specimens, while the saline and nonenzymatic process allowed for the comparable recovery of cells and tissue for evaluation. Conclusion: Adequate numbers of cells are dissociated from the tissue core when needle biopsies are washed. The recovery and preservation of cells and tissue for morphological interpretation was optimal when solutions devoid of enzymes were used for washing.