NEWS & EVENTS

Case of the Month - February 2011

Warren Lowman; Trusha Nana; Norma Bosman
Department of Clinical Microbiology & Infectious Diseases, School of Pathology, University of the Witwatersrand.

A 13 year old insulin-dependent diabetic presented to her local clinic with three days of pain and swelling on her left gum associated with fever and swelling of the left side of the face. She was sent home on oral amoxicillin-clavulanate for five days, but did not improve.

She subsequently presented to Rahima Moosa Hospital, where she was noted to have swelling of the buccal mucosa and bilateral periorbital oedema. This seemed more pronounced on the left side. On clinical examination, the left side of the face was extremely tender, erythematous and extensively swollen. A collection of pus was noted on the maxilla, extending to the left eye.

She was immediately transferred to Charlotte Maxeke Johannesburg Academic Hospital and seen by the maxillo-facial and ENT Surgeons who diagnosed left facial-orbital cellulitis. She had conjunctival injection, proptosis and reduced eye movement in the left eye. The pharynx was normal and no abnormality was detected on rhinoscopy.

CT scan of the brain (figure 1) revealed mucosal thickening of the left ethmoid and maxillary sinuses. No intracranial or cavernous sinus thrombosis was seen.



Figure 1: CT Brain



The patient was taken to theatre that same evening for a biopsy and to exclude a fungal infection. She was found to have necrotic, devitalized periorbital soft tissue, with an area of blackening of the left globe medially. Necrotic and devitalized tissue was also found in the mucosa of the ethmoid and maxillary sinuses.

A working diagnosis of mucormycosis was made and a left fronto-ethmoidectomy, left medial maxillectomy and debridement of devitalized tissue was performed. Specimens were submitted to the microbiology laboratory for fungal staining and culture and also to histopathology.

She was admitted to ICU and started empirically on amphotericin B and cefotaxime.

Laboratory Results:



C-Reactive Protein [mg/L] 393
Total WBC x 109/L 11.9
Neutrophils x 109/L 79.5%
Random Glucose mmol/L 13.8
HBA1c 10%


Microbiology

Special fungal stains of tissue samples from the maxillary and ethmoid sinuses, and preseptal area using the potassium hydroxide (KOH) and periodic-acid Schiff (PAS) stains revealed the presence of fungal hyphae in all the specimens. On fungal culture, using both macroscopic (Figure 2a) and microscopic morphology (figure 2b), the mould was identified as a Rhizopus spp.



Figure 2a Macroscopic colonial morphology of fungal isolate



Figure 2b Lactophenol-blue stain demonstrating the microscopic morphology of isolate



Figure 3 shows the results of histopathological examination of the same tissue. The areas of tissue necrosis contained aggregates of aseptate fungal hyphae, which were noted to invade the underlying tissue and vasculature, in keeping with features of mucormycosis. This was further confirmed by special fungal stains (PAS /Grocott’s) which highlighted evidence of invasion by fungal hyphae.





Figure 3 [H&E stain]: numerous fungal elements with tissue invasion and ischaemic necrosis



Question 1: What are the clinical manifestations of mucormycosis?

Continue to Answer 1

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