Mvc de Silva

Zeil Neelson and Wade‐Fite stains to demonstrate medlar bodies of chromoblastomycosis

To the Editor, The characteristic fungal bodies of chromoblastomycosis, known as Medlar bodies, are visualized as golden brown rounded bodies in routine hematoxylin and eosin (H&E) stained tissue sections of the skin (Fig. 1). We report a hither to undocumented staining pattern of Medlar bodies that will be useful when they are not identified in routine H&E stains, in cases with a high index of clinical suspicion. Chromoblastomycosis is a chronic fungal infection of skin and subcutaneous tissue seen in rural populations of tropical and subtropical regions. The commonly reported causative fungi are Fonsecaea pedrosoi, Phialophora verrucosa and Cladosporium carrionii. The organisms after gaining entry to the body through traumatic skin injury produce a slow growing verrucous nodule or a plaque. The histological diagnosis of the disease is by staining tissue sections of skin with the H&E stain to demonstrate Medlar bodies. A 72-year-old female presented with a non-itchy warty growth on the dorsum of the left foot of oneyear duration. The warty growth had a hyperkeratotic center with peripheral scarring. The clinical differential diagnosis in this patient included warty tuberculosis and chromoblastomycosis. H&E-stained sections of the lesion showed epidermal hyperplasia and a dense chronic inflammatory infiltrate with illformed granulomata within the dermis. Although these histological features supported a diagnosis of chromoblastomycosis, the characteristic Medlar bodies were not seen. Therefore, the Zeil Neelson stain (ZNS) was performed to rule out the possibility of warty tuberculosis. In the ZNS sections, Medlar bodies were seen prominently as dark grayish oval bodies against a light blue background (Fig. 2). Subsequently, ZNS was performed on tissue sections of three confirmed cases of chromoblastomycosis retrieved from the departmental case files. A similar pattern of staining was seen in all three cases confirming that Medlar bodies of chromoblastomycosis are stained by the ZNS, traditionally used to demonstrate acid fast bacilli. Following this, Wade-Fite staining (WFS) was done on tissue sections in the above patients. Medlar bodies stained positively with WFS in a pattern similar to that seen with the ZNS (Fig. 3). Medlar bodies were easier to identify in the ZNS and WFS than in the routine H&E-stained slides as all inflammatory cells and the back ground stained