Case report:
A 44-year-old diabetic man was hospitalized for the management of a blackish necrotic lesion in the left auricle with significant locoregional extension. The history of his disease goes back to ten days before hospitalization: he had a pretragal swelling, with a bluish zone, quickly evolving to a blackish necrotic lesion centered on the left auricle associated with a pretragal fistula. This lesion extended anteriorly to the parotid region, superiorly to the temporal region and posteriorly to the retroauricular region (Fig 1). Purulent otorrhea, otalgia, and left hearing loss were present. Otoscopic examination revealed a blackish tissue filling the external auditory canal and a secretion-covered eardrum that was bluish after aspiration. The rhinological, endobuccal and cervical examinations were normal. The patient had a left peripheral facial palsy (grade IV of House and Brackmann classification) associated with a left vocal cord palsy. The rest of the neurological examination was normal.
Biologically: the blood count showed a hyperleukocytosis of 21240 cells/mm3 (92% neutrophils, with lymphopenia: 3.3% lymphocytes, i.e. 700/mm3), normocytic normochromic anemia with a hemoglobin level of 9.2 gr/dl, and platelets of 233,000/mm3. CRP and blood sugar levels were high (respectively 254 mg/L and 260 mg/dL).
High‑resolution computed tomography of the temporal bone showed thickening of the left peri-auricular soft tissues, filling of the left external auditory canal, middle ear and mastoid cells without bone lysis or nasosinusal involvement or endocranial extension (Fig 2 - Fig 3). Magnetic resonance imaging with gadolinium injection showed infiltration of the subcutaneous soft tissues extending to the homolateral masticatory, parapharyngeal and parotid spaces with collection in the left parotid region and the masticatory space communicating with the homolateral parapharyngeal space, exerting a mass effect on the pharyngo-laryngeal lumen (Fig 4 - Fig 5).
The patient underwent a biopsy of the auricle. Histopathology showed the presence of mucormycosis mycelia filaments. The culture was positive with the presence of Rhisopus
Microspores . Liposomal Amphotericin B was immediately administered at a dose of 5 mg/kg/d. The collection was drained under general anesthesia. Bacteriological examination of the drained abscess isolated Klebsiella Pneumonia confirming bacterial superinfection and the patient was treated by Vancomycin – Imipenem associated with Amphotericin B. However, an immediate surgical debridement surgery was not possible because of poor surgical risk owing to the extensive inflammation around these necrotic lesions.
A regression of the parotid swelling, local inflammatory signs and biological inflammatory syndrome were noted. However, the necrotic lesion extended inferiorly and superiorly to the temporoparietal region with spontaneous anterior detachment of the necrotic plaque (Fig 6). This plaque was lined with underlying budding tissue which motivated us to perform a surgical debridement of the necrotic lesions with total excision of the left auricle and external auditory canal. (Fig 7). An informed consent was obtained from the patient before surgery.
After several months, a healing of the substance loss was obtained by secondary Intention healing (a cover flap was not necessary) (Fig 8). However, facial and left vagus nerve paralysis persisted without any real recovery.