PMC7186520_01
Lesion on the left arm characterized by cellulitis and ulcer with tissue necrosis consistent with primary cutaneous mucormycosis.
gr1.jpg
PMC7186520_01_gr1.jpg
fig0005
Over the next 48 h, the lesion progressed to an ulcer with extension to subcutaneous cell tissue and progression of the necrotic area, despite intensive treatment by the wound care team with healings, hydrating dermal wound dressings with sodium alginate and carboxymethylcellulose, as hydrocolloids to cover the lesion (Fig. 1).
Direct evaluation of tissue culture with lactophenol blue 400x, showing structures compatible with Rhizopus spp.
gr2.jpg
PMC7186520_01_gr2.jpg
fig0010
Fungal cultures obtained during skin biopsy, revealed the growth of a mold that was classified by phenotypic characteristics as Rhizopus spp. (Fig. 2).
Histopathology of skin biopsy: (A) Necrotic ulcer extending up to the subcutaneous cellular tissue (Hematoxylin & Eosin -HE- staining 10x). (B) Base of the ulcer with few broad and aseptate hyphae (HE, 40x). (C, D) Broad aseptate hyphae with right angle branching seen on skin ulcer (Grocott's methenamine silver staining 40x).
gr3.jpg
PMC7186520_01_gr3.jpg
fig0015
Mucorales (Fig. 3). Mass spectroscopy (matrix-assisted laser desorption/ ionization-time mass spectrometry of flight mass spectroscopy MALDI-TOF MS, BD  Buker MALDI Biotyper System) and polymerase chain reaction (PCR) plus sequencing from culture (panfungal PCR, sequencing region D1/ D2 -24S RNA long subunit-, internal transcribed spacer region) identified Rhizopus arrhizus (formerly R. oryzae) as the fungus responsible for the infection.