Rhino-orbital-cerebral mucormycosis

Pre- and posttreatment imaging findings

Abstract

Mucormycosis is a fungal infection typically affecting diabetic or immunocompromised patients. Very few cases have been reported in the literature in the past but multiple studies have shown that it is increasing, especially in this COVID era. It is highly invasive in nature hence early diagnosis is obligatory. Radiological imaging plays an important role in its diagnosis and to evaluate the extent of disease, in turn facilitating timely intervention. The objective of this clinical report is to evaluate a case of rhino-orbital-cerebral mucormycosis that involved the medical and surgical treatment of an immunocompromised male patient. In this interventional case study, a comprehensive evaluation of presenting features and imaging diagnostic evaluation are discussed in detail.

INTRODUCTION

COVID-19 has given space to many opportunistic infections to bloom but the way mucormycosis had made its way, none other have. Mucormycosis is an acute, meteoric, and usually, lethal infection typically affecting diabetic or immunocompromised patients. Because of its lethal nature, it must be recognized early and treated aggressively. Radiological imaging plays an important role in its diagnosis and to evaluate the extent of disease, in turn facilitating timely intervention.[¹] Herein, we report on a case of rhino-orbital-cerebral mucormycosis (ROCM) in a diabetic patient with chronic kidney disease, who reported to us with pathology afflicting the right eye, paranasal sinuses (PNS), nasal cavity, and hard palate. This case report studies the pre- and postinterventional treatment radiological features.

CASE REPORT

A 65-year-old poorly controlled diabetic male patient presented with facial swelling, nasal discharge, and blocked nose for more than 20 days in the month of November 2020. He also complained of nasal regurgitation of fluids for the past 10 days. Apart from type II diabetes, he had chronic kidney disease and hypertension and a history of an old cerebrovascular accident.

Examination showed swelling of the right middle third face, proptosis [Figure 1], and tenderness at the zygomatic, periorbital, and lateral nasal regions. Intraoral palatal fistula measuring 1 cm × 2 cm was present on the right half of the hard palate, covered with necrotic slough, which was sent for biopsy. The absence of bleeding on probing from exposed palatal bone confirms the presence of necrotic bone. Eleven–fifteen were grade 1 mobile and 16 were grade 2 mobile. Intranasally, there was nasal crusting and the mucosa was pale. A nasal swab was collected and sent for culture and sensitivity. Considering the COVID-19 era, reverse transcriptase–polymerase chain reaction test from nasopharyngeal swab was done on which he tested negative for the COVID-19 virus.

Figure 1: Swelling of right upper half of face, redness around eyes, and right side proptosis

Computed tomography (CT) scan showed chronic infarct with gliosis in the right occipital lobe. Cerebrospinal fluid attenuation area was noted in the right peripheral cerebellum and cerebellopontine angle region (likely to be chronic infarct) and in the external capsule and corona radiata region (sequelae to previous hemorrhage). Inhomogeneous soft-tissue densities are present in the right buccal, masticator, pharyngeal mucosal spaces, subcutaneous maxillary cheek, and nasal region [Figure 2]. In the right infraorbital region, mild proptosis was seen [Figure 3]. Lamellar soft-tissue density lesions were noted filling the right PNS (maxillary, frontal, ethmoidal, and sphenoidal) [Figure 4]. Bony erosion with irregularities and destruction of the right superior alveolar ridge and posterior inferior wall of the maxillary sinus was noted [Figure 5]. These features were suggestive of inflammatory changes/infective etiology. In the left inferior maxillary sinus and middle ethmoidal area, inflammatory thin mucosal thickening was noted. Mild left-side deviated nasal septum was seen. The bilateral parotid region left masticator and left buccal spaces appeared normal. There was no significant size of the neck adenopathy in the neck region.

Figure 2: CT scan coronal section showing inhomogeneous soft-tissue densities. CT: Computed tomography

Figure 3: CT scan coronal section showing mild proptosis. CT: Computed tomography

Figure 4: CT scan coronal section showing lamellar soft-tissue densities lesions were noted filling the right paranasal sinuses. CT: Computed tomography

Figure 5: CT scan axial section showing bony erosion and destruction of the right superior alveolar ridge. CT: Computed tomography

Management

First, for the prevention of nasal regurgitation, a customized palatal obturator [Figure 6] was given to the patient. Betadine gargle three times a day was advised to maintain oral hygiene. Nasal culture and sensitivity and KOH staining showed fungal growth (cotton white colony). Biopsy of palatal slough favored mucormycosis. The final diagnosis of ROCM was made. Both medical (injection amphotericin B 50 mg and low-dose steroid) and surgical treatment (endoscopic sinus debridement of the right maxillary sinus, as patient denied for partial maxillectomy) along with ear–nose–throat surgeons were planned. After discharge, the patient was shifted on oral posaconazole 900 mg in three divided doses, a tapering dose of prednisolone, and other supportive immunity booster medications.

Figure 6: Palatal fistula closure with palatal obturator to prevent nasal regurgitation

Second noncontrast computed tomography (NCCT) PNS was advised in the month of January 2021 which showed bony destruction of the anterior and lateral wall of the right maxillary sinus with hemosinus, left maxillary sinusitis, blocked left nasal vestibule, and fracture of the anterior maxilla and right nasal bone. The presence of right frontal sinusitis and bilateral blocked osteomeatal complexes was there. Left frontal, ethmoidal, and sphenoidal sinuses reveal normal aeration, and no mucosal thickening or fluid levels were seen. The nasal fossae appeared normal without any mass and the orbits were normal [Figure 7].

Figure 7: Second CT scan coronal section showing postoperative changes. CT: Computed tomography

Magnetic resonance imaging (MRI) brain was done in the month of February 2021 and showed no new developments in the brain. In the PNS region, T2 hyperintense mucosal thickening was noted in the bilateral maxillary, right ethmoidal, right frontal, and sphenoidal sinuses (inflammatory). Postoperative changes were noted in the right maxillary sinus and nasal septum. Edema was noted in soft tissue and muscle planes of the right infratemporal fossa (inflammatory) [Figure 8].

Figure 8: MRI showed edema in soft tissue and muscle planes of the right infratemporal fossa. MRI: Magnetic resonance imaging

Third, NCCT PNS done in the month of April 2021 revealed soft-tissue density mucosal thickening in bilateral maxillary sinus with bony destruction of walls of the right maxillary sinus, orbital and maxillary floor, palatine bone, and posterior alveolar ridge (patient 16 tooth exfoliated) [Figure 9]. Soft-tissue densities were also noted in the right pterygopalatine fossa, retromolar fat, masticator space, and nasal cavity. Further postoperative changes are noted in the right maxillary sinus antrum. Further postoperative changes are noted in the right maxillary sinus antrum. In February 2022 anterior maxillectomy was done as patient was having difficulty in mastication. For prosthetic rehabilitation removable partial denture was given.

Figure 9: CT scan axial section showed soft-tissue density mucosal thickening in bilateral maxillary sinus with bony destruction of walls of the right maxillary sinus, orbital and maxillary floor, palatine bone, and posterior alveolar ridge. CT: Computed tomography

The patient is being followed to date and is continued on oral posaconazole and supportive medications [Figure 10].

Figure 10: Recent clinical image of the patient

DISCUSSION

Mucormycosis is known acutely fatal fungal infection occurring to humans. Mucormycosis, first described by Paulltauf in 1885, is also known as zygomycosis and phycomycosis. These are ubiquitous fungi occurring in soil, air, skin, body orifices, manure, spoiled food, and dust. Its inoculation in the body occurs by inhalation when spores reach the nasal cavity and/or nasopharynx. The fungus then starts spreading to the PNS and subsequently to the orbit, meninges, and brain by direct extension.[²] The nasolacrimal duct and medial orbital wall are the routes to spread to the orbital region and this are possible due to the thinness of the lamina papyracea. Rhino maxillary orbital mucormycosis is a scarce invasive infection which affects immunocompromised and uncontrolled diabetes mellitus (one of the most important risk factors) patients.[³]

Early recognition of the fungal infection is crucial for initiating therapy and avoiding potentially devastating complications. Initial CT scan imaging is the examination of choice and also the preferred method for evaluation of possible bony destruction. Similar approach we took in our case to know the extent of the disease. CT has 100% sensitivity and 78% specificity in the diagnosis of sinonasal mycosis. This scan demonstrates hyperdense content leading to erosions of bony sinus walls and this hyperdensity in the affected sinus is highly suggestive of fungal disease.[⁴] Such an image was also noted in our case where lamellar soft-tissue densities were filling the right PNS and the hyperdense aggressive content mass extends beyond the confines of the sinus cavity and led to erosions of bony sinus walls. Inflammation extending to the soft tissues of the anterior cheek in patients with maxillary sinusitis is highly suggestive of fungal sinusitis.[⁵] Our present case pretreatment shows inhomogeneous soft-tissue densities in the right buccal, right masticator, right pharyngeal mucosal spaces, and subcutaneous right maxillary cheek.

CT imaging features may mimic sinus carcinoma but the diagnosis of invasive mycotic infections should be studied in fitting clinical settings. Again it is critical to differentiate the invasive infection from noninvasive because the treatment and prognosis differ in each condition. The disease can be diagnosed in initial stages if the compromised health of patient with few clinical feature and initial CT scan images shows mucosal thickening.[⁶]

High accuracy is seen with axial and coronal sections in CT and it makes a good noninvasive modality of accurately imaging sinonasal mycosis. In our case, all the diagnosed extent of the lesion was ruled out on axial and coronal sections.[⁷]

Survival rates are between 50% and 80% when limited involvement of the PNS is present, however, when brain invasion has occurred, mortality is greater than 80%. Our patient was diagnosed in the month of October 2020, and after medical and endoscopic surgical treatment, he is keeping well, but still on medication.[⁸]

The objective of this case report is to describe the common radiographic pattern, pre- and posttreatment, which may be useful in predicting the progression of disease and imaging changes in patient with ROCM. 1.5 month postoperative CT apart from pretreatment findings showed two positive outcomes, first, nasal fossae appeared normal without any mass, and second, the orbits were normal.

Later after 1 month, MRI done had postoperative changes in the right maxillary sinus and nasal septum along with inflammatory changes in soft tissue and muscle planes of the right infratemporal fossa.[^5,9]

Recently, last CT done in April month additionally showed mucosal thickening in the bilateral maxillary sinus with postoperative changes in the right maxillary sinus. Furthermore, there was bony destruction of all the right maxillary antrum walls, orbital and maxillary floor, palatine bone, and posterior alveolar ridge.

Pre- and posttreatment CT scan of the present case clearly infers that mucormycosis has high invasive nature and if not addressed timely, this disease may affect the brain and lungs. Furthermore, patient had difficulty in mastication and his health permitted, anterior maxillectomy was done and rehabilitated with removable prosthesis. Due to our instant and right approach to treatment morbidity was markedly reduced.

CONCLUSION

Although mucormycosis is common in immunocompromised and diabetic patients, this disease was rare in prevalence in the pre-COVID-19 era, but frequent now. Imaging study of a single case is a limitation of this study and further case reports are needed to reach the conclusion. However, we can infer with this report that an early diagnostic imaging study is helpful in restricting the disease progression to severe cases with high mortality. In addition, periodic imaging helps us keeping check. Finally, as stressed in earlier studies, our case also shows that aggressive treatment with antifungal medications and wide debridement is the key to the successful management of paranasal mycosis.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

Acknowledgement

We great fully thank Dr. B. B Karunamay CMO I/C Bokaro general hospital for his endless motivation towards research and academics.