Annals of African Medicine

ORIGINAL ARTICLE
Year
: 2014  |  Volume : 13  |  Issue : 3  |  Page : 119--123

Analysis of computed tomography features of fungal sinusitis and their correlation with nasal endoscopy and histopathology findings


Kamini Gupta, Kavita Saggar 
 Department of Radiodiagnosis, Dayanand Medical College and Hospital, Ludhiana, Punjab, India

Correspondence Address:
Kamini Gupta
Department of Radiodiagnosis, Dayanand Medical College and Hospital, Ludhiana, Punjab
India

Abstract

Objective: The purpose of this study was to analyze the computed tomography (CT) features of fungal sinusitis and to correlate them with nasal endoscopy and histopathological findings. Materials and Methods: Our study included 16 patients of either sex and any age group who presented in the otorhinolaryngology clinic at our hospital and had evidence of definite sinonasal disease on clinical evaluation. Multidetector CT was carried out on Somatom definition AS + 128 slice CT Machine by Siemens Germany Ltd. Axial sections were performed with the plane of data acquisition parallel to the hard palate and slice thickness of 3 mm, reconstructions at 0.75 mm in coronal and sagittal planes. Scanning parameters included 190 mA S, 120 KV and tube rotation time of 0.5 s. Provisional CT diagnosis was made in all cases and correlated with nasal endoscopy and histopathological findings. Results: Out of total 16 patients, 12 showed immunocompromised status and had infection with mucormycosis. Out of 12, 9 patients (75%) showed extension of disease beyond the sinonasal cavities and 4 (33.3%) showed evidence of bone destruction. All patients with candidiasis showed soft-tissue attenuation with hyperdense areas on CT scan. Nearly, 66.6% patients with aspergillosis showed soft-tissue attenuation with hyperdense areas and expansion of sinonasal cavities. Fifteen patients (93%) were proved to be of fungal sinusitis on histopathology. One patient of non-specific granulomatous infection showed bone destruction and mimicked fungal sinusitis on CT. Conclusions: In the present study, fungal sinusitis could be correctly diagnosed on CT with high accuracy. Thus, understanding the different CT findings of fungal sinusitis allows the radiologist to play a crucial role in the diagnosis and prompt treatment.



How to cite this article:
Gupta K, Saggar K. Analysis of computed tomography features of fungal sinusitis and their correlation with nasal endoscopy and histopathology findings.Ann Afr Med 2014;13:119-123


How to cite this URL:
Gupta K, Saggar K. Analysis of computed tomography features of fungal sinusitis and their correlation with nasal endoscopy and histopathology findings. Ann Afr Med [serial online] 2014 [cited 2019 Sep 16 ];13:119-123
Available from: http://www.annalsafrmed.org/text.asp?2014/13/3/119/134398


Full Text

 Introduction



Fungal sinusitis is an important clinical problem with diverse manifestations. It should be considered in all immunocompromised patients and in all patients with chronic sinusitis. [1] The most recent and widely accepted classification of fungal sinusitis is broadly categorized as either invasive or non-invasive. Invasive fungal sinusitis is sub-divided into acute invasive fungal sinusitis, chronic invasive fungal sinusitis and chronic granulomatous invasive fungal sinusitis. Non-invasive fungal sinusitis is sub-divided into allergic fungal sinusitis and fungus ball. [2] Its successful treatment requires a prompt diagnosis and frequently relies on radiologic imaging, specifically computed tomography (CT) imaging. In the present study, we have studied CT features of fungal sinusitis.

Purpose

The present study was undertaken to evaluate the CT features of fungal sinusitis, to classify them into invasive and non-invasive types and to further correlate CT findings with nasal endoscopy and histopathology diagnosis.

 Materials and Methods



A prospective study of 16 cases of either sex and any age group who were presented in the otorhinolaryngology clinic, at our hospital and were found to have evidence of definite sinonasal disease on clinical evaluation was taken up.

All patients included in this

study were assessed as follows.

Clinical details

Detailed history regarding nasal obstruction, nasal discharge, epistaxis, sneezing and orbital symptoms was takenRelevant past and family history was takenDetailed findings of general and local examination including anterior and posterior rhinoscopy, oral and ophthalmoscopic examinations were recorded.

CT

Multidetector CT was carried out on Somatom definition AS+ 128 slice CT Machine by Siemens Germany Ltd. After obtaining the scout projection, the area of scanning was defined to include the region from the roof of frontal sinus until the hard plate.

Axial sections were performed with patient in the supine position and the plane of data acquisition parallel to the hard palate. The sections were taken with slice thickness of 3 mm and reconstructions were carried out at 0.75 mm in coronal and sagittal planes. Scanning parameters included 190 mA S, 120 KV and tube rotation time of 0.5 s. Extended cephalic/caudal sections were carried out in few cases to see the extension of the disease process.

Contrast enhanced CT was performed wherever indicated after giving a rapid bolus injection of 50 ml of non-ionic iodinated contrast material.

The images thus generated were reconstituted at appropriate window widths and window levels to depict the soft-tissue pathologies as well as bony abnormalities.

Provisional CT diagnosis was made in all cases based on CT pattern and pertinent clinical data.

Various CT patterns suggestive of fungal sinusitis were intrasinus high density nodular or linear interlacing areas, expansion of sinuses with thinning or erosion of bony walls, bone sclerosis or remodeling, extension of disease into adjacent soft-tissues, orbits or cranium. CT diagnosis was correlated with nasal endoscopic and histopathological diagnosis in all cases.

All patients underwent surgical debridement of sinuses and nasal cavities. Biopsies were taken for histopathology and restoration of drainage of sinuses was done.

Systemic antifungals were given to the patients depending upon the nature of fungus and extent of disease. Itraconazole and lipid based amphotericin B was given to patients with aspergillosis and mucormycosis respectively for duration of 3-6 months. Most of patients with allergic fungal sinusitis responded well; however, patients with acute invasive fungal sinusitis having extrasinus extension and decreased neutrophil count showed poor response and eight patients died within 6 months.

 Results



Sixteen patients with CT diagnosis of fungal sinusitis were included in our study [Table 1]. Out of these, 12 patients showed immunocompromised status in the form of diabetes mellitus acquired immune deficiency syndrome renal allograft recipient and acute/chronic myeloid leukemia and had an infection with mucormycosis.{Table 1}

All these patients presented within 2-3 weeks of onset of symptoms. Most common symptoms were due to orbital or intracranial extension of disease.

Out of 12, 9 patients (75%) showed extension of disease beyond the sinonasal cavities [Figure 1] and [Figure 2]. Four patients (33.3%) showed evidence of bone destruction and expansion of sinuses was not seen in any case. Out of these 12 cases, 9 patients showed unilateral pansinusitis and 3 patients had bilateral disease.{Figure 1}{Figure 2}

All patients with candidiasis showed soft-tissue attenuation with hyperdense areas on CT scan. Two out of three patients (66.6%) with aspergillosis also showed evidence of soft-tissue attenuation with hyperdense areas [Figure 3] and expansion of sinonasal cavities [Figure 4].{Figure 3}{Figure 4}

Patients with aspergillosis and sporothrix infection had symptoms since 6-12 months and had a history of allergy to dust and pollens with seasonal exacerbations. Two out of three patients of aspergillosis and patient with sporothrix infection had bilateral distribution of disease.

Out of 16 patients with CT diagnosis of fungal sinusitis, 13 patients had evidence of crustacean and necrotic material (suggestive of fungal infection) on nasal endoscopy. One patient with sporothrix schenckii infection showed polypoidal masses with cheesy material on nasal endoscopy and was interpreted as inflammatory sinonasal polyposis on endoscopy. Two cases of aspergillosis were also diagnosed as inflammatory polyposis on endoscopy as there was no evidence of mucosal invasion.

Out of 16 patients with CT diagnosis of fungal sinusitis, 15 patients (93%) were correctly diagnosed as proved on histopathology. One patient of non-specific granulomatous infection was wrongly interpreted as fungal sinusitis on CT scan because of the presence of erosion of the hard palate, which is common in acute invasive fungal sinusitis [Figure 5].{Figure 5}

 Discussion



Acute invasive fungal sinusitis is a rapidly progressing and most lethal form of fungal sinusitis, with a reported mortality of 50-80%. [3]

Up to 80% of invasive fungal infections in this group are caused by fungi belonging to the order Zygomycetes, such as Rhizopus, Rhizomucor, Absidia and Mucor and infection by these organisms is sometimes termed zygomycosis. [4]

The diagnosis of acute invasive fungal sinusitis is always a dilemma as the most common CT feature is non-specific mucosal hypertrophy and in some cases hyperdense attenuation is not seen, as in 75% cases in our study. However, the presence of immunocompromised status, bone erosion, extension beyond sinonasal cavities in conjunction with nasal endoscopy findings can clinch the diagnosis in all cases.

In chronic invasive fungal sinusitis, inhaled fungal organisms are deposited in the asal passage and paranasal sinuses. Insidious progression occurs over several months to years, in which fungal organisms invade the mucosa, submucosa, blood vessels and bony walls of the paranasal sinuses. This results in significant morbidity and may even be fatal. Common organisms include Mucor, Rhizopus, Aspergillus, Bipolaris and Candida. On imaging in such cases, hyperdense attenuation with bony sclerosis and expansion is the most important clue to diagnosis as seen in our study.

In allergic fungal sinusitis, there is usually involvement of multiple sinuses if not pansinusitis and rhinitis. Disease tends to be bilateral and there is a frequent nasal component. The majority of the sinuses show near-complete opacification and are expanded. Non-contrast CT demonstrates hyperdense attenuation. [5]

Fungus ball appears as a mass within the lumen of a paranasal sinus and is usually limited to one sinus. The maxillary sinus is the most commonly involved sinus. There is usually calcification in the fungal hyphae. [6]

 Conclusions



In the present study, considering histopathological diagnosis as the gold standard, fungal sinusitis could be correctly diagnosed on CT with high accuracy as only 1 patient (out of 16) of non-specific granulomatous infection was wrongly interpreted as fungal sinusitis.

Understanding the different types of fungal sinusitis and knowing their particular radiologic features allows the radiologist to play a crucial role in alerting the clinician to use appropriate diagnostic techniques for confirmation. Prompt diagnosis and initiation of appropriate therapy are essential to avoid a protracted or fatal outcome. However, the sample data of the present study is limited, we need to study these CT features in a larger sample of patients and may be able to strongly emphasize the crucial role of CT scan in the diagnosis of fungal sinusitis in future.

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