The Utility of Frozen Section in the Detection of Invasive Fungal Species in Combat-Related Injury
Kevin Downing, David Tribble, Justin Wells. Walter Reed National Military Medical Center, Bethesda, MD; Uniformed Services University of the Health Sciences, Bethesda, MD
Background: Invasive fungal infection is an uncommon but serious complication of traumatic injury. One retrospective review of U.S. military personnel returning from combat operations in Iraq and Afghanistan with combat-related injuries over a six-year period reported an overall incidence of 0.4 cases per 1000 admissions, with a peak in incidence of 5.2 cases per 1000 admissions temporally associated with increased operational tempo in theater. We would like to report our institution's experience with the utility of frozen sections in guiding management of invasive fungal infections in combat-related traumatic injuries.
Design: A review of frozen section evaluations for fungal elements performed on combat-related soft tissue injuries involving U.S. military personnel deployed in support of Operations Enduring Freedom and Iraqi Freedom in Afghanistan and Iraq, respectively, from July 2010 to August 2011 was performed. A total of 147 samples from 48 patients were evaluated intraoperatively for the presence of invasive fungal species using hematoxylin and eosin stained frozen sections, and then later correlated with permanent H&E sections and Gomori methenamine silver (GMS) staining.
Results: Routine permanent and special stains demonstrated fungal elements in 24 of 147 specimens, with 19 of 48 patients having at least one sample positive for fungus on permanent sections. The false positive rate was 1.4% (2/147), and the false negative rate was 10.9% (16/147), with a sensitivity of 60.0% and a specificity of 98.1%.
Conclusions: Invasive fungal infection is a rare but life-threatening complication of traumatic injury often requiring aggressive medical and surgical management. Our experience suggests that while frozen section evaluation can be a helpful adjunct, its low sensitivity makes it suboptimal as a stand-alone intraoperative screening test for fungal elements. We hypothesize that the observed false negative rate is likely attributable to inherently poor staining characteristics of fungal organisms in general, coupled with the known limitations and interpretive difficulties associated with frozen sections. Due to these difficulties, our institution subsequently transitioned from screening for fungal elements via intraoperative consultation to expedited traditional tissue processing with H&E and GMS stained sections with rapid turn-around to ensure optimal, timely management of this unique patient population.
Tuesday, March 5, 2013 2:35 PM
Proffered Papers: Section H2, Tuesday Afternoon