Mycological study on cholesteatoma keratin obtained during primary mastoid surgery K G EFFAT 1 , N M MADANY 2 1 Department of Otolaryngology, El-Sahel Teaching Hospital, and 2 Department of Medical Microbiology and Immunology, Faculty of Medicine, Cairo University, Cairo, Egypt Abstract Objective: Established middle-ear cleft cholesteatoma is associated with keratinous debris, which is likely to be an ideal medium for saprophytic fungal colonisation. This prospective case study aimed to explore the incidence and nature of fungal elements in cholesteatoma keratin samples obtained during primary mastoid surgery. Methods: All cases of middle-ear cleft cholesteatoma treated with primary mastoid surgery at the El-Sahel Teaching Hospital over a seven-month period were included. Keratinous debris obtained from the mastoid antrum was subjected to mycological analysis at the Department of Medical Microbiology and Immunology, Faculty of Medicine, Cairo University. A literature search was performed to determine the clinical and pathological relevance of fungal colonisation in cholesteatoma. Results: Eighteen patients underwent primary mastoid surgery for cholesteatoma (nineteen ears in total) in a seven-month period starting 30 March 2013. Patients included 13 males and 5 females, with an age range of 9 to 45 years (mean 23 years). Fungal cultures were obtained from 17 keratin samples (89 per cent). Of these, five fungal isolates belonged to the dermatophyte group (21 per cent). Conclusion: Fungal colonisation in middle-ear cleft cholesteatoma probably plays a significant role in disease progression. Moreover, saprophytic fungal colonisation in cholesteatoma keratin may be responsible for the fetor commonly associated with the ear discharge. Key words: Cholesteatoma; Microbiology; Fungi Introduction Fungi are a diverse group of saprophytic (i.e. derive nourishment from dead organic matter) and parasitic eukaryotic organisms. Fungal pathogenicity is deter- mined by the host’s immune response and virulence factors specific to the fungus. Fungal features that are not present in other microorganisms are a rigid cell wall and the formation of large hyphae, which are fre- quently present in clinical specimens. Both features enable fungi to resist the host’s defence mechanisms. In normal hosts, fungal isolation commonly reflects colonisation rather than infection. However, in patients with an abnormal immune response, a wide spectrum of fungal-related diseases can develop. 1 Fungal infection of the ear is most commonly restricted to the external auditory canal. 2 Middle-ear cleft cholesteatoma is a gradually expanding, destruc- tive epithelial lesion. Established cholesteatoma con- tains keratinous debris, which is probably an ideal medium for saprophytic fungal colonisation. 3 In this prospective study, we performed a fungal ana- lysis of keratinous debris samples obtained during primary mastoid surgery from patients with choles- teatoma presenting to El-Sahel Teaching Hospital, Cairo. We determined the frequency and nature of fungal elements associated with cholesteatoma. A PubMed and Medline search from 1980 until 2013 was performed using the search terms ‘cholesteatoma’ and ‘fungi’. The literature was reviewed to determine the clinical and pathological relevance of fungal colon- isation in middle-ear cleft cholesteatoma. As far as we are aware, this is the first prospective mycological study to be specifically performed on cholesteatoma keratin samples obtained during primary mastoid surgery. Materials and methods Approval from the local ethics committee and informed consent from the patients or guardians of children participating in the study were obtained. Patients with cholesteatoma who presented consecutively during the 7 months from 30 March 2013 onwards and were operated on at the El-Sahel Teaching Hospital in Cairo were included. Accepted for publication 27 January 2014 First published online 19 September 2014 The Journal of Laryngology & Otology (2014), 128, 881–884. MAIN ARTICLE © JLO (1984) Limited, 2014 doi:10.1017/S0022215114002059