Safe transportation of formalin-fixed liquid-free pathology specimens

Diagnostic pathology activities are largely based on fixation of tissues in 4% formaldehyde, which has recently been re-classified as a carcinogenic compound and banned in several countries. Hospitals that do not have in-house pathology services need to send surgical and biopsy specimens to referral centers. These are generally transferred in liquid containers, under suboptimal safety conditions, as accidental spillage of potentially dangerous substances may occur. A safe, innovative, two-step procedure for pathology sample transportation is presented. Formalin-fixed material from ten surgical cases was dissected (including surrogate biopsies) and preserved in liquid-free plastic bags under vacuum for up to 30 days and subsequently processed for conventional histology, several immunohistochemical markers, and molecular tests (e.g., RAS mutation). The data were compared with the corresponding routine analyses. Formalin-fixed specimens after up to 30 days under vacuum storage gave equivalent results compared to standard histopathological slides and molecular tests, regarding both hematoxylin-eosin, immuno-stained slides and also nucleic acid extracted for molecular tests. The proposal of under-vacuum sealing pathology specimens that were previously formalin fixed can be adopted to transfer liquid-free biopsy and surgical specimens to referral pathology services. In fact, it is easy to perform, less expensive (both plastic bags and domestic-type vacuum chamber machines are at affordable costs), and above all is fully safe and adequate in the pre-analytical processing of pathology specimens.