Effect of histologic processing on dimensions of skin samples obtained from cat cadavers

Abstract

OBJECTIVE To determine changes in dimensions of feline skin samples as a result of histologic processing and to identify factors that contributed to changes in dimensions of skin samples after sample collection. SAMPLE Cadavers of 12 clinically normal cats. PROCEDURES Skin samples were obtained bilaterally from 3 locations (neck, thorax, and tibia) of each cadaver; half of the thoracic samples included underlying muscle. Length, width, and depth were measured at 5 time points (before excision, after excision, after application of ink to mark tissue margins, after fixation in neutral-buffered 10% formalin for 36 hours, and after completion of histologic processing and staining with H&E stain). Measurements obtained after sample collection were compared with measurements obtained before excision. RESULTS At the final time point, tissue samples had decreased in length (mean decrease, 32.40%) and width (mean decrease, 34.21%) and increased in depth (mean increase, 54.95%). Tissue from the tibia had the most shrinkage in length and width and that from the neck had the least shrinkage. Inclusion of underlying muscle on thoracic skin samples did not affect the degree of change in dimensions. CONCLUSIONS AND CLINICAL RELEVANCE In this study, each step during processing from excision to formalin fixation and histologic processing induced changes in tissue dimensions, which were manifested principally as shrinkage in length and width and increase in depth. Most of the changes occured during histologic processing. Inclusion of muscle did not affect thoracic skin shrinkage. Shrinkage should be a consideration when interpreting surgical margins in clinical cases. 945).

Longitudinal study of rat volar fat pad fixation and ethanol storage: implications for the use of fluid‐preserved specimens in morphological studies

“…), and 35% for linear measurements for skin samples (Jeyakumar et al. ). Findings are more varied for studies where full or composite specimens are examined, but morphometric studies of fish larvae and associated preservation artifacts prove particularly instructive.…”

“…This was not the case when muscle (65–70% water per unit volume, Schmidt, ) was left attached to excised skin (65% water, Schmidt, ); no reduction in shrinkage for either tissue was noted (Jeyakumar et al. ). Taken together, these pieces of evidence indicate that the most rigid and/or anhydrous tissue is a limiting factor to the amount of shrinkage experienced by composite tissues.…”

“…; Jeyakumar et al. ; Hedrick, 2018) , but composite tissues experience small, predictable changes in dimensions that may be mitigated through extension of joints during preservation (Bininda‐Emonds & Russell, , ; Kansu et al. ).…”

“…This unequal warping affects soft tissues more drastically than hard tissues, which comprise lower percentages of water and receive additional support from rigid minerals in their matrices (Schmidt, 1989;Butler, 1992;Takizawa et al 1994;Margo & Lee, 1995;Vervust et al 2009;Korwin-Kossakowski, 2014;Kansu et al 2017;Hedrick et al 2018). These disparities also highlight the potential for inconsistent artifact formation when full and partial specimens are preserved, as well as the potential for allometric size effects in the formation of preservation artifacts (Fox et al 1985;Fey, 1999Fey, , 2012Edwards et al 2009;Vickerton et al 2013;Korwin-Kossakowski, 2014;Jeyakumar et al 2015).…”

Reductions in margin length after excision of grade II mast cell tumors and grade I and II soft tissue sarcomas in dogs

“…The latter is explained by microscopic infiltration of the GNSM, resulting in a narrower HTFM . Other relevant prior publications tested length reductions in normal (ie, non‐neoplastic) tissues, and may therefore not apply to tumor‐bearing specimens; in addition, retrospective studies have not been able to determine at which point of tissue processing did these changes occur …”