The clinical manifestations of mucormycosis are classified as rhinocerebral, pulmonary, gastrointestinal, cutaneous, and disseminated, among which rhinocerebral is the most common. The clinical manifestation of RCM is intense inflammation centered on the nasal cavity, sinuses, and surrounding soft tissues, with atypical early symptoms such as runny nose, nasal congestion, oral/facial mucosal skin necrosis, scab formation, upper-palate black ulcer lesions, facial swelling, and so forth. Sinusitis with facial, nasal, or palate painless black scab formation is a characteristic of RCM, usually suggesting a poor prognosis[4]. In the present case, nasal congestion, runny nose, and oral and upper-palate ulcer formation are still being followed up. As RCM progresses, the orbital and intracranial regions may be involved, with manifestations of symptoms such as orbital cellulitis, orbital apical syndrome, headache, hemiplegia, epilepsy, loss of consciousness, and so forth.
The gold standard for diagnosing RCM is a histopathological examination and fungal culture. For early diagnosis, PCR, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and blood mNGS are being attempted[6]. RCM can involve intracranial tissues and nerves, but it is not suitable for cerebrospinal fluid analysis and diagnosis [7]. In such cases, the blood mNGS examination suggests the presence of rhizomold, but histopathological examination and fungal smear are needed to confirm the diagnosis. Imaging examinations such as CT and magnetic resonance imaging may indicate the lesion site, scope, and bone destruction. In vertical samples of tissue specimens, the presence of a large number of thick and indivisible hyphae is the “gold standard” for confirming the diagnosis. Comparatively, characteristic changes such as hemorrhagic infarction, coagulation necrosis, vascular thrombosis, neutrophil infiltration, and invasion of nerve structure can also be seen [8]. The histopathology of focal chronic RCM is characterized by chronic granulomatous changes, mainly multinucleated giant cells, and highly eosinophilic deposits around hyphal or spore structures, which is also known as Splendore–Hoeppli phenomenon[9].
The European Confederation of Medical Functionalities treatment guidelines recommend a diagnosis and treatment strategy for mucormycosis, including early diagnosis, control of the underlying disease, systemic antifungal therapy, and appropriate surgical debridement therapy[10]. In the present case, we recommended the following:
1. Active treatment of hematological diseases
2. Treatment using drugs mainly amphotericin B, amphotericin B liposomal complex, posaconazole, and oxiconazole. The recommended dose of amphotericin B is 1.0–1.5 mg/(kg × d), with a maximum dose of 2.5–4.0 g[11] and a treatment duration of 4–6 weeks[12]. Amphotericin B liposomal complex is currently recognized as the first-line treatment of mucormycosis. The European Union Medical Association recommends an amphotericin B liposomal complex dose of 5–10 mg/(kg × d) [13]. Posaconazole and oxiconazole are mainly used as salvage therapy, with the recommended dose of 200 mg taken four times a day [4]. The exact course of treatment for mucormycosis is unclear. It is considered under treatment until the clinical symptoms and imaging manifestations have completely disappeared.
3. Surgical debridement. If the physical condition of the child allows, the diseased tissue can be removed based on the condition of the patient. First, nasal endoscopic surgery with clear vision and less trauma is performed. The surgery is conducted as extensively and thoroughly as possible while ensuring that the sinus complex and middle nasal tract drainage is unobstructed until the healthy tissue is exposed; even multiple clearances can be performed. In the present case, the child underwent nasal endoscopy under general anesthesia, and the lesion was removed until no further hair mold was found in the slides. The clinical data suggest that early surgical debridement combined with antifungal drug treatment may improve the survival rate of children[14]. This study showed that the survival rate with antifungal treatment alone was 72.5%[15]. The study also showed a survival rate of 61% within 12 days, 33% after 13 days, and only 21% in children without surgical debridement.
To sum up, if symptoms such as fever, nasal mucosal ulceration, and formation of black scab skin in the nasal cavity and oral mucosa appear in ALL, the possibility of hair mold infection should be considered. Also, the histopathological diagnosis should be clarified by improving nasal endoscopy, imaging, and blood mNGS as soon as possible. The patient should receive antifungal drugs and surgical treatment as soon as possible. Early diagnosis and treatment are crucial for the prognosis of this disease and for improvement in the survival rate of children.