Utility of frozen section analysis for fungal organisms in soft tissue wound debridement margin determination

Abstract

BackgroundZygomycetes cause different patterns of infection in immunosuppressed individuals, including sino-orbito-cerebral, pulmonary, skin/soft tissue infection and disseminated disease. Infections with Zygomycetes have a high mortality rate, even with prompt treatment, which includes anti-fungal agents and surgical debridement. In some centers, clear margins are monitored by serial frozen sections, but there are no specific guidelines for the use of frozen sections during surgical debridement. Studies in fungal rhinosinusitis found 62.5–85 % sensitivity of frozen section analysis in margin assessment. However, the utility of frozen section analysis for margin evaluation in debridement of skin/soft tissue infection has not been published.MethodsWe present a case of zygomycosis of decubitus ulcers in which we assessed statistical measures of performance of frozen section analysis for presence of fungal organisms on the margin, compared with formalin-fixed paraffin embedded (FFPE) sections as gold standard. A total of 33 specimens (94 blocks) were sectioned, stained with H&E and evaluated by both frozen and FFPE analysis. Negative interpretations were confirmed by Gomori methenamine silver stain on FFPE sections.ResultsH&E staining of frozen sections had 68.4 % sensitivity and 100 % specificity for assessing margins clear of fungal organisms. The negative and positive predictive values were 70.0 % and 100 %, respectively. Using presence of acute inflammation and necrosis as markers of fungal infection improved sensitivity (100 %) at the expense of specificity (42.9 %).ConclusionUse of intraoperative assessment of skin and soft tissue margins for fungal infection is a valuable tool in the management of skin and soft tissue fungal infection treatment.

Histopathological techniques for the diagnosis of combat-related invasive fungal wound infections

“…Overall, the findings observed in this military setting are comparable with other publications, which found frozen sections to be largely predictive of IFIs in patients with rhinosinusitis [ 15 , 25 , 26 ]. Furthermore, an assessment of 33 specimens collected from a patient with fungal-infected bedsores found 68 % sensitivity and 100 % specificity of frozen sections in the soft-tissue margin evaluation in wound debridement [ 27 ], which is comparable to our findings.…”

Cutaneous mucormycosis

“…There is a report on the use of frozen sections to help the pathologist and surgeon define the final surgical margins during surgical debridement of the affected tissue. 60 …”

Isolated cutaneous mucormycosis in a pediatric renal transplant recipient

“…Use of intraoperative frozen sections to delineate the extent of surgical excision has been successfully employed in rhino‐orbital‐cerebral mucormycosis. However, in cutaneous mucormycosis, frozen section analysis for the presence of fungal organisms on the margin via H&E staining was found to have a sensitivity of only 68.4% and a negative predictive value of 70% . Walsh et al first described successful use of intraoperative calcofluor staining in the management of periodontal mucormycosis.…”

“…However, in cutaneous mucormycosis, frozen section analysis for the presence of fungal organisms on the margin via H&E staining was found to have a sensitivity of only 68.4% and a negative predictive value of 70%. 8 Walsh et al 9 first described successful use of intraoperative calcofluor staining in the management of periodontal mucormycosis. In our case, only 1 of 4 quadrants of excised tissue samples was calcofluor negative but fungal culture positive.…”