Autopsy Analysis On Epidemiology and Site of Involvement Of Invasive Fungal Infections (IFI) In Hematological Malignancies : A Retrospective Study at Hematologic Tertiary Care  Department

Clinical diagnosis of IFI is difficult ,due to lack of sensitive and specific diagnostic tools. An assessment of trends concerning the prevalence of IFI is a challenge and postmortem data may be useful to monitor the local epidemiology ,the frequency and the disease patterns.

The aim of this retrospective analysis is to determinate the local epidemiology and the prevalence at autopsy of IFI, occurring in hematological malignancies at a single center  over a eleven years period.

We have retrospectively reviewed 161 patients – median age  62,5 yrs, range 22 -83 - with hematological malignancies, who underwent autopsy between 2002 -2012. Acute Myeloid Leukemia (AML) were 77, Acute Lymphoid  Leukemia (ALL) 11,  Lymphoproliferative disorders (LPD) 56 and other disorders 17. Acute leukemia pts received systemic antifungal  prophilaxis, whereas the others not absorbable prophilaxis. None patients received transplant procedures. An experienced pathologist evaluated the organ involvement and the IFI pathologic pattern. Fisher’s Exact test was used to recognize the IFI prevalence, the main occurring pathogens and the involved site; a p-value of <0.05 was considered statistically significant.

The analysis of 161 consecutive autopsies identified 40  pts.(25%)resulting to have IFI; of these, 22 were AML (55%) ,6 ALL (15%),11LPD (28%) and 1 other. Aspergillus  spp. infection was detected in 20 cases (50%), Mucor spp in 8 (20%) and Candida spp. in 12 (30%). Moulds  were prevalent in acute leukemia pts. and Aspergillus spp. is the leading pathogen with respect to Candida and Mucor spp. (p 0,0396),with a statistically significant prevalence in ALL (p 0,0186).The site more involved resulted lung (p 0.0002). Whereas the standardized EORTC/MSG criteria applied in vivo were conclusive for  IFI in 6  pts ( 15%) only, the postmortem findings revealed fungal infections in further 34  pts (85%).

This analysis confirms that the IFI diagnosis is still an unresolved issue in hematological malignancies. Acute leukemias remain the subset with the higher prevalence of mould infections. As in other largest studies, in our experience Aspergillus spp and lung proved to be the most recurrent pathogen and site of involvement. At now, the diagnostic methods are not still completely able to identify the underlying IFI, thus  the autopsy rate should be increased to achieve a better knowledge of epidemiology and to critically review previous misdiagnosis.

No relevant conflicts of interest to declare.