'Unstained' and 'de stained' sections in the diagnosis of chromoblastomycosis: a clinico-pathological study.

Background: Diagnosis of chromoblastomycosis is frequently missed for many reasons: (1) rarity of the lesion (2) requirement of careful search for diagnostic 'sclerotic' bodies which are often sparse in clinical material such as tissue and exudates (3) often they elicit tissue reactions such as verrucous lesion and micro abscesses, misleading the diagnosis (4) lack of 'clinical suspicion'.

Aims: (1) To compare the feasibility of 'unstained', 'stained' and 'de stained' sections in identification of the diagnostic ' sclerotic' bodies (2) To study histopathological features of chromoblastomycosis, and (3) To highlight the importance of clinical suspicion in the diagnosis of chromoblastomycosis.

Design: This is a retrospective study conducted on six clinically unsuspected, histopathologically diagnosed cases of chromoblastomycosis.

Results: Most common clinical presentation was verrucous lesion over extremities affecting adult men engaged in outdoor works. Sclerotic bodies and their characteristic features were easily identified in both 'unstained' and 'de stained' sections. Special stains such as Fontana Masson and Gomori's methenamine silver nitrate are useful for demonstrating hyphal forms in keratinized layers and for illustration purposes.

Conclusion: Both 'unstained' and 'de stained' sections can be used for rapid screening of sclerotic bodies. 'De stained' sections can be used as a suitable substitute for special stains for confirmation and for retrospective review of all verrucous lesions to diagnose the missed lesion. Clinical suspicion is very important in the diagnosis of chromoblastomycosis as it helps pathologist to screen for diagnostic sclerotic bodies.