APPEARANCE OF FUNGUS IN TISSUE 



201 



Fig. 101. Chromoblastomycosis. Chlamy- 



dospores of Phialophora Pedrosoi in 



tissue. 



Diagnosis. The early lesions closely resemble those of North 

 American blastomycosis and must be differentiated by laboratory 

 methods. The older verrucous lesions are more diagnostic. Exam- 

 ination of sections made from the lesion will reveal the brown, thick- 

 walled chlamydospores of the fungus. In some cases one can peel 

 off some of the epidermal scales 

 at the edge of the lesion and 

 mount them in 10 per cent 

 sodium hydroxide under a cover 

 slip as in examining for derma- 

 tophytosis. In such prepara- 

 tions the fungus can sometimes 

 be found growing as brown hy- 

 phae in these superficial scales. 



The laboratory diagnosis is 

 not complete without the isola- 

 tion of the fungus in culture, 

 because any one of at least 

 three fungi may cause the dis- 

 ease and there is no correlation 

 between a particular clinical type of lesion and one of the fungi 

 causing chromoblastomycosis. 



Prognosis and Treatment. The prognosis for cure of chromo- 

 blastomycosis is poor but the disease does not become systemic and 

 does not endanger life. Early lesions may be excised or destroyed 

 by electrocoagulation. They sometimes heal under irradiation or 

 after administration of iodides. Some success has been reported in 

 the use of copper sulphate iontophoresis. 



Appearance of Fungus in Tissue. In the superficial epidermal 

 scales the fungus may be found in the form of septate branching 

 hyphae with thick brown walls. In the subcutaneous tissues how- 

 ever it is present in a more characteristic form as small clusters of 

 chlamydospores. The disease was called chromoblastomycosis be- 

 cause the origin of these clusters was interpreted as a budding proc- 

 ess. Actually, true budding does not occur, although something ap- 

 proaching budding is seen in some cells. In most cases the cell 

 elongates and is divided by a septum. This elongation and septum 

 formation takes place in any plane so that there results a small 

 cluster of cells with th^ck, dark brown walls. If growth of the 

 fungus is rapid these clusters may contain several cells and in such 

 cases they differ only in size from the granules seen in some types 



