Histochemical Evaluation of Skin Lesions from Cutaneous Leishmaniasis Patients: Comparison of Processing with Xylene or Coconut Oil

Introduction:

Cutaneous leishmaniasis (CL) is a notifiable disease, and histopathological analysis constitutes one of the main diagnostic methods. Changes in the extracellular matrix in the skin can vary according to the infection time and parasitemia. Therefore, histopathological preparation must be performed appropriately, allowing for the preservation of structures. In this context, coconut oil has been used as a substitute for xylene with the aim of improving the quality of biological samples. The objective of this study was to compare the histochemical quality of skin lesion samples from CL patients processed with xylene and with coconut oil.

Methodology:

Skin biopsies were fixed in 10% formalin, dehydrated in ethanol solutions, cleared with coconut oil or xylene, and embedded in paraffin. The histological sections were stained with hematoxylin and eosin (H&E), reticulin, Masson’s trichrome, and Sirius red.

Results:

After H&E staining, it was observed that samples processed with coconut oil showed images with better extracellular matrix quality. Similarly, samples processed with coconut oil had greater preservation of the extracellular matrix, as evidenced by Masson’s trichrome and Sirius red staining. However, with reticulin staining, type 3 collagen fibres were better visualized in samples processed with xylene.

Conclusions:

The processing of skin lesion samples from leishmaniasis patients yielded better quality when processed with coconut oil, as evidenced by H&E, Masson’s trichrome, and Sirius red staining.