Lung and sinus fungal infection imaging in immunocompromised patients.

BACKGROUND: Imaging is a key diagnostic modality for suspected invasive pulmonary or sinus fungal disease and may help to direct testing and treatment. Fungal diagnostic guidelines have been developed and emphasize the role of imaging in this setting. We review and summarize evidence regarding imaging for fungal pulmonary and sinus disease (in particular invasive aspergillosis, mucormycosis and pneumocystosis) in immunocompromised patients. OBJECTIVES: We reviewed data on imaging modalities and findings used for diagnosis of invasive fungal pulmonary and sinus disease. SOURCES: References for this review were identified by searches of PubMed, Google Scholar, Embase and Web of Science through 1 April 1 2023. CONTENT: Computed tomography imaging is the method of choice for the evaluation of suspected lung or sinus fungal disease. Although no computed tomography radiologic pattern is pathognomonic of pulmonary invasive fungal disease (IFD) the halo sign firstly suggests an angio-invasive pulmonary aspergillosis while the Reversed Halo Sign is more suggestive of pulmonary mucormycosis in an appropriate clinical setting. The air crescent sign is uncommon, occurring in the later stages of invasive aspergillosis in neutropenic patients. In contrast, new cavitary lesions should suggest IFD in moderately immunocompromised patients. Regarding sinus site, bony erosion, peri-antral fat or septal ulceration are reasonably predictive of IFD. IMPLICATIONS: Imaging assessment of the lung and sinuses is an important component of the diagnostic work-up and management of IFD in immunocompromised patients. However, radiological features signs have sensitivity and specificity that often vary according to underlying disease states. Periodic review of imaging studies and diagnostic guidelines characterizing imaging findings may help clinicians to consider fungal infections in clinical care thereby leading to an earlier confirmation and treatment of IFD.

The vanishing nasal septum sign: a case of severe fungal sinusitis.

Acute invasive fungal sinusitis (AIFS) is a fungal infection of the nasal cavity and paranasal sinuses with associated invasion of adjacent vessels and soft/hard tissues. It usually occurs in immunocompromised patients and may follow a rapid course of less than four weeks with high mortality rate. We report a 39-year-old male with relapse of acute myelogenous leukemia (AML) who was under evaluation for neutropenic fever. On his sinus CT, there was loss of calcification of his nasal septum when compared to a prior head CT, a sign indicative of an aggressive infectious process. He was diagnosed with AIFS and underwent emergent surgical debridement and systemic antifungal therapy, leading to a positive outcome. The sign described on CT ("Vanishing Nasal Septum" sign) may provide an additional, reliable tool to prospectively identify locally aggressive cases of invasive fungal infections of the nasal cavity at an earlier stage and improve patient outcomes.

Radiology-based diagnosis of fungal pulmonary infections in high-risk hematology patients: are we making progress?

PURPOSE OF REVIEW: In patients with hematological malignancies, high-resolution computed tomography (CT) is the recommended imaging approach for diagnosis, staging and monitoring of invasive fungal disease (IFD) but lacks specificity. We examined the status of current imaging modalities for IFD and possibilities for more effective applications of current technology for improving the specificity of IFD diagnosis. RECENT FINDINGS: Although CT imaging recommendations for IFD are largely unchanged in the last 20 years, improvements in CT scanner technology and image processing algorithms now allow for technically adequate examinations at much lower radiation doses. CT pulmonary angiography can improve both the sensitivity and specificity of CT imaging for angioinvasive molds in both neutropenic and nonneutropenic patients, through detection of the vessel occlusion sign (VOS). MRI-based approaches also show promise not only for early detection of small nodules and alveolar hemorrhage but can also be used to detect pulmonary vascular occlusion without radiation and iodinated contrast media. 18F-fluorodeoxyglucose (FDG) PET/computed tomography (FDG-PET/CT) is increasingly used to monitor long-term treatment response for IFD, but could become a more powerful diagnostic tool with the development of fungal-specific antibody imaging tracers. SUMMARY: High-risk hematology patients have a considerable medical need for more sensitive and specific imaging approaches for IFD. This need may be addressable, in part, by better exploiting recent progress in CT/MRI imaging technology and algorithms to improve the specificity of radiological diagnosis for IFD.

Determining the usefulness of systematic 18F-FDG PET/CT for the management of invasive fungal infection (PETIFI project): a prospective national multicentre cohort study protocol.

INTRODUCTION: The evaluation of staging and activity of invasive fungal infection (IFI) is used to adjust the type and duration of antifungal therapy (AT). Typically anatomy-based imaging is used. Positron emission tomography/CT with 18F-fluorodeoxyglucose (18F-FDG PET/CT) not only evaluates more than one body area in one session, but adds functional information to the anatomic data provided by usual imaging techniques and can potentially improve staging of IFI and monitoring of the response to therapy. Our objective is to analyse the impact of the systematic use of 18F-FDG PET/CT in IFI diagnostic and therapeutic management. METHODS AND ANALYSIS: Multicentre prospective cohort study of IFI with performance of systematic 18F-FDG PET/CT at diagnosis and follow-up that will be carried out in 14 Spanish tertiary hospitals. It is planned to include 224 patients with IFI over a 2-year study period. Findings and changes in management before and after 18F-FDG PET/CT will be compared. Additionally, the association of initial quantitative 18F-FDG PET/CT parameters with response to therapy will be evaluated.The primary endpoint is to compare the yield of 18F-FDG PET/CT with standard management without 18F-FDG PET/CT in IFI at initial assessment (staging) and in monitoring the response to treatment.The impact of the results of 18F-FDG PET/CT on the diagnostic-therapeutic management of patients with IFI (added value), as well as the prognostic ability of different quantification parameters of 18F-FDG PET/CT will be secondary endpoints. ETHICS AND DISSEMINATION: The Clinical Research Ethics Committee of Puerta de Hierro-Majadahonda University Hospital approved the protocol of the study at the primary site. We plan to publish the results in high-impact journals. TRIAL REGISTRATION NUMBER: NCT05688592.

Imaging of Invasive Fungal Infections- The Role of PET/CT.

Over the last decades, the population at risk for invasive fungal disease (IFD) has increased because of medical therapy advances and diseases compromising patients' immune systems. The high morbidity and mortality associated with invasive fungal disease in the immunocompromised present the challenge of early diagnosis of the IFD and the need to closely monitor the infection during treatment. The definitive diagnosis of invasive fungal disease based on culture or histopathological methods often has reduced diagnostic accuracy in the immunocompromised and may be very invasive. Less invasive and indirect evidence of the fungal infection by serology and imaging has been used for the early diagnosis of fungal infection before definitive results are available or when the definitive methods of diagnosis are suboptimal. Imaging in invasive fungal disease is a non-invasive biomarker that helps in the early diagnosis of invasive fungal disease but helps follow-up the infection during treatment. Different imaging modalities are used in the workup to evaluate fungal disease. The different imaging modalities have advantages and disadvantages at different sites in the body and may complement each other in the management of IFD. Positron emission tomography integrated with computed tomography with [18F]Fluorodeoxyglucose (FDG PET/CT) has helped manage IFD. The combined functional data from PET and anatomical data from the CT from almost the whole body allows noninvasive evaluation of IFD and provides a semiquantitative means of assessing therapy. FDG PET/CT adds value to anatomic-based only imaging modalities. The nonspecificity of FDG uptake has led to the evaluation of other tracers in the assessment of IFD. However, these are mainly still at the preclinical level and are yet to be translated to humans. FDG PET/CT remains the most widely evaluated radionuclide-based imaging modality in IFD management. The limitations of FDG PET/CT must be well understood, and more extensive prospective studies in uniform populations are needed to validate its role in the management of IFD that can be international guidelines.

Fungal biomarker monitoring and CT scans for early detection of invasive fungal disease in neutropenic hematological patients.

OBJECTIVES: By using data from the CEDMIC trial (n = 413), we conducted a post-hoc analysis of the diagnostic value of biomarker monitoring and chest computed tomography (CT) scans for the early detection of invasive fungal disease (IFD) in neutropenic hematological patients. METHODS: IFDs were defined in accordance with the EORTC/MSG definition with some modifications. Biomarkers such as Aspergillus galactomannan (GM) and (1→3)-ß-D-glucan (ßDG) were measured weekly. RESULTS: The positive predictive value (PPV) of GM and ßDG in cases of high-risk treatment were 0.70 and 0.69, while those in low-risk treatment were 0.08 and 0, respectively. All of the positive biomarkers that were measured before the development of fever in low-risk treatment were false positives. The proportion of patients who had abnormal chest CT findings was 19% in persistent fever at 4-6 days, 57% at 7 days or later and 36% in recurrent fever. Sixty-nine percent of the patients who had abnormal findings at 7 days or later did not have abnormalities at 4-6 days. CONCLUSIONS: Afebrile screening of biomarkers in low-risk treatment is not useful. Chest CT should be reevaluated in persistent fever lasting for 7 days or longer even in patients who did not have abnormalities within 6 days.

Rinosinusitis micótica alérgica con destrucción de base de cráneo / Allergic fungal rhinosinusitis with skull base destruction

La sinusitis micótica alérgica es una enfermedad inflamatoria de la mucosa rinosinusal producida por hongos que pueden aislarse de la cavidad de nasal de individuos sanos. Se produce indirectamente por los hongos que actúan como antígeno y desencadenan una reacción inmunológica mediada por IgE que origina pólipos y una secreción mucosa espesa con detritus e hifas denominada mucina. Su presentación clínica más frecuente es una sinusitis crónica unilateral o bilateral con pólipos. Con menos frecuencia, las sustancias originadas por la desgranulación de los eosinófilos producen remodelación o destrucción ósea y la sinusitis puede simular una neoplasia. Se describe el caso clínico de un paciente que padeció una sinusitis micótica alérgica con destrucción ósea masiva de la base del cráneo y que tuvo extensión intracraneal extradural e intraorbitaria de la enfermedad. Fue tratado con éxito mediante cirugía y corticoides. (AU)

Allergic fungal sinusitis is an inflammatory disease of the rhinosinusal mucosa caused by fungi that can be isolated from the nasal cavity of healthy individuals. The pathology is produced indirectly by the fungus that acts as an antigen and triggers an IgE-mediated allergic reaction that causes polyps and a thick mucous discharge with detritus and hyphae called mucin. Its most common clinical presentation is unilateral or bilateral chronic sinusitis with polyps. Less commonly, substances originated by the degranulation of eosinophils cause bone remodeling or destruction, and sinusitis can simulate a neoplasia. We describe the clinical case of a patient who suffered from allergic fungal sinusitis with massive bone destruction of the skull base and who had intracranial, extradural and intraorbital extension of the disease. He was successfully treated with surgery and corticosteroids.Key words: allergic fungal sinusitis, intracranial extension, endoscopic surgery, transorbital transpalpebral approach. (AU)

Revisiting rhino-orbito-cerebral acute invasive fungal sinusitis in the era of COVID-19: pictorial review.

COVID-19 patients have been found to have an increased incidence of superadded fungal infections because of multiple factors such as impaired cell-mediated immunity, immunosuppressive therapy, and coexistent diabetes mellitus. Recently, there has been a significant rise in the COVID-19-associated mucormycosis and aspergillosis cases involving the sinonasal cavity and the lungs. Rhino-orbito-cerebral acute invasive fungal rhinosinusitis (AIFR) is a potentially life-threatening, invasive fungal infection. Early diagnosis followed by prompt medical management and surgical intervention is crucial for patient survival. The role of cross-sectional imaging (CT/MRI) is not only to suggest a diagnosis of invasive fungal sinusitis but also to delineate the complete extent of disease. Mapping the extent of orbital and intracranial disease has prognostic as well as management implications, as involvement of these sites marks a worse prognosis. A stepwise approach to evaluation of imaging of AIFR along with a pictorial depiction of the key imaging findings is presented.

Fatal disseminated aspergillosis in an immunocompetent patient with COVID-19 due to Aspergillus ochraceus.

Aspergillus infection is a well-known complication of severe influenza and severe acute respiratory syndrome coronavirus (SARS-CoV), and these infections have been related with significant morbidity and mortality even when appropriately diagnosed and treated. Recent studies have indicated that SARS-CoV-2 might increase the risk of invasive pulmonary aspergillosis (IPA). Here, we report the first case of Aspergillus ochraceus in a SARS-CoV-2 positive immunocompetent patient, which is complicated by pulmonary and brain infections. Proven IPA is supported by the positive Galactomannan test, culture-positive, and histopathological evidence. The patient did not respond to voriconazole, and liposomal amphotericin B was added to his anti-fungal regimen. Further studies are needed to evaluate the prevalence of IPA in immunocompetent patients infected with SARS-CoV-2. Consequently, testing for the incidence of Aspergillus species in lower respiratory secretions and Galactomannan test of COVID-19 patients with appropriate therapy and targeted anti-fungal therapy based on the primary clinical suspicion of IPA are highly recommended.

The role of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (FDG PET/CT) in assessment of complex invasive fungal disease and opportunistic co-infections in patients with acute leukemia prior to allogeneic hematopoietic cell transplant.

INTRODUCTION: Individuals diagnosed with acute lymphoid and myeloid malignancies are at significant risk of invasive fungal and bacterial infections secondary to their marked immunocompromised states with a significant high risk of mortality. The role of metabolic imaging with 18F-Fluorodeoxyglucose (FDG) Positron Emission Tomography/Computed Tomography (PET/CT) has been increasingly recognized in optimizing the diagnosis of invasive infection, monitoring the response to therapy and guiding the duration of antimicrobial therapy or need to escalate to surgical intervention. METHODS: Two distinct cases of pulmonary co-infection of rare fungal and bacterial pathogens are explored in severely immunocompromised individuals where FDG PET/CT aided both patients to make a full recovery and transition to HCT. The first case explores mixed Scedosporium apiospermum and Rhizomucor pulmonary infection on a background of T cell/myeloid mixed phenotype acute leukemia ultimately warranting long-term antifungal therapy and lobectomy prior to HCT. The second case explores Fusarium and Nocardia pulmonary infection on a background of relapsed AML also warranting surgical resection with lobectomy and long-term antimicrobials prior to transition to HCT. DISCUSSION: The cases highlight the utility of FDG PET/CT to support the diagnosis of infections, including the presence or absence of disseminated infection, and to provide highly sensitive monitoring of the infection over time. FDG PET/CT played a key role in directing therapy duration decisions and prompted the necessity for surgical intervention. Ultimately, the use of FDG PET/CT allowed for a successful transition to HCT highlighting its value in this clinical setting. CONCLUSION: FDG PET/CT has an emerging role in the diagnostic and monitoring pathway for complex infections in high-risk immunocompromised patients.

The use of imaging to identify immunocompromised children requiring biopsy for invasive fungal rhinosinusitis.

BACKGROUND AND PURPOSE: Children with severe immunocompromise due to cancer therapy or hematopoietic cell transplant are at risk both for potentially lethal invasive fungal rhinosinusitis (IFRS), and for complications associated with gold-standard biopsy diagnosis. We investigated whether early imaging could reliably identify or exclude IFRS in this population, thereby reducing unnecessary biopsy. METHODS: We reviewed clinical/laboratory data and cross-sectional imaging from 31 pediatric patients evaluated for suspicion of IFRS, 19 without (age 11.8 ± 5.4 years) and 12 with proven IFRS (age 11.9 ± 4.6 years). Imaging examinations were graded for mucosal thickening (Lund score), for fungal-specific signs (FSS) of bone destruction, extra-sinus inflammation, and nasal mucosal ulceration. Loss of contrast enhancement (LoCE) was assessed separately where possible. Clinical and imaging findings were compared with parametric or nonparametric tests as appropriate. Diagnostic accuracy was assessed by receiver operating characteristic (ROC) analysis. Positive (+LR) and negative likelihood ratios (-LR) and probabilities were calculated. RESULTS: Ten of 12 patients with IFRS and one of 19 without IFRS had at least one FSS on early imaging (83% sensitive, 95% specific, +LR = 15.83, -LR = 0.18; P < .001). Absolute neutrophil count (ANC) ≤ 200/mm3 was 100% sensitive and 58% specific for IFRS (+LR = 2.38, -LR = 0; P = .001). Facial pain was the only discriminating symptom of IFRS (P < .001). In a symptomatic child with ANC ≤ 200/m3 , the presence of at least one FSS indicated high (79%) probability of IFRS; absence of FSS suggested low (<4%) probability. CONCLUSION: In symptomatic, severely immunocompromised children, the presence or absence of fungal-specific imaging findings may effectively rule in or rule out early IFRS, potentially sparing some patients the risks associated with biopsy.

Gastrointestinal involvement of unusual Mucormycete Syncephalastrum racemosum in a diabetic patient with adenocarcinoma: rare case presentation with review of literature.

BACKGROUND: Mucormycosis is a serious and often fatal mycotic infection caused by members of class Mucormycetes in populations with immunologic or metabolic disorders. Though several clinical manifestations are associated with mucormycetes, gastrointestinal involvement is quite rare. CASE DESCRIPTION: We described a rare case of invasive fungal infection due to Syncephalastrum racemosum associated with gastric adenocarcinoma in a 48-year-old male patient with type II Diabetes mellitus. He presented with complaints of abdominal pain, nausea, vomiting, dyspepsia, dysphagia, loss of appetite, and weight. Histopathological examination showed broad and aseptate hyphae and culture of endoscopic biopsy tissue from pylorus and antrum yielded the fungal pathogen S. racemosum. The species was confirmed by molecular sequencing of D1/D2 region of the ribosomal DNA. The in vitro susceptibility of S. racemosum was tested by broth microdilution assay as per CLSI guidelines. The MICs suggest that the isolate was susceptible to Amphotericin B (0.25 µg/ml), Itraconazole (0.25 µg/ml) and Posaconazole (0.06 µg/ml) and showed resistance to Micafungin (>16 µg/ml). The patient was successfully treated with radical subtotal gastrectomy with lymphadenectomy and Amphotericin B antifungal therapy. There was a dilemma in concluding the pathogenicity of the isolate since; the symptoms noted were common for both gastric adenocarcinoma and mucormycosis. A review of previously reported cases on Syncephalastrum was presented in the paper with their clinical manifestations, treatment, and outcome. CONCLUSION: To the best of our knowledge, this is the first report from India on the gastrointestinal involvement of S. racemosum. Patients with immunocompromised status are more prone to mucormycotic infections, and any typical presentations should be carefully examined for their etiological agent, and appropriate species directed therapy would help in a better outcome.

Chronic invasive fungal rhinosinusitis vs sinonasal squamous cell carcinoma: the differentiating value of MRI.

OBJECTIVES: To investigate MRI features in discriminating chronic invasive fungal rhinosinusitis (CIFRS) from sinonasal squamous cell carcinomas (SNSCC). METHODS: MRI findings of 33 patients with CIFRS and 47 patients with SNSCC were retrospectively reviewed and compared. Multivariate logistic regression analysis was performed to identify significant imaging features in distinguishing between CIFRS and SNSCC. The ROC curves and the AUC were used to evaluate diagnostic performance. RESULTS: There were significant differences in cavernous sinus involvement (p < 0.001), sphenoid sinus involvement (p < 0.001), meningeal involvement (p = 0.024), T2 signal intensity (p = 0.006), and enhancement pattern (p < 0.001) between CIFRS and SNSCC. Multivariate logistic regression analysis identified cavernous sinus involvement (odds ratio [OR] = 0.06, 95% confidence interval [95% CI] = 0.02-0.20) and sphenoid sinus involvement (OR = 0.14, 95% CI = 0.05-0.45) as significant indicators for CIFRS and T2 isointensity to gray matter (OR = 4.44, 95% CI = 1.22-16.22) was a significant indicator for SNSCC. ROC curve analysis showed the AUC from a combination of three imaging features was 0.95 in differentiating CIFRS and SNSCC. CONCLUSIONS: MRI showed significant differences between CIFRS and SNSCC features. In immunocompromised patients, a sinonasal hypointense mass on T2WI with septal enhancement or loss of contrast enhancement, and involvement of cavernous sinus, sphenoid sinus, and meninges strongly suggest CIFRS. KEY POINTS: • Chronic invasive fungal rhinosinusitis (CIFRS) is often difficult to distinguish from sinonasal squamous cell carcinomas (SNSCC) in clinical practice. • Cavernous sinus and sphenoid sinus involvement appear to be significant indicators for CIFRS. T2 isointensity to gray matter appears to be a significant indicator for SNSCC. • Loss of contrast enhancement and septal enhancement can be used to distinguish CIFRS from SNSCC with a high degree of specificity.

Treatment outcomes in acute invasive fungal rhinosinusitis extending to the extrasinonasal area.

Acute invasive fungal rhinosinusitis (AIFRS) can spread beyond the sinonasal cavity. It is necessary to analyze the association between the specific site involved in the extrasinonasal area and the survival rate to predict patient prognosis. We investigated 50 patients who had extrasinonasal lesions on preoperative gadolinium (Gd)-enhanced magnetic resonance imaging (MRI) scan and underwent wide surgical resection of AIFRS. The specific sites with loss of contrast enhancement (LoCE) on Gd-enhanced MRI were analyzed for AIFRS-specific survival rate. The most common underlying disease was diabetes mellitus followed by hematological malignancy. The most common symptoms were headache and facial pain. Seven patients (14.0%) expired because of AIFRS progression. Poor prognosis was independently associated with LoCE at the skull base on preoperative MRI (HR = 35.846, P = 0.004). In patients with AIFRS extending to the extrasinonasal area, LoCE at the skull base was an independent poor prognostic factor.

A Rare Case of Chromoblastomycosis in a 12-year-old boy.

Chromoblastomycosis is a chronic fungal infection of the subcutaneous tissue. The infection usually results from a traumatic injury and inoculation of the microorganism by a specific group of dematiaceous fungi, resulting in the formation of verrucous plaques. The fungi produce sclerotic or medlar bodies (also called muriform bodies or sclerotic cells) seen on direct microscopic examination of skin smears. The disease is often found in adults due to trauma. We report a case of chromoblastomycosis in a 12-year-old child in whom the infection started when he was only 4 years old with secondary involvement of bones, cartilage, tongue and palatine tonsils. The child was not immunosuppressed.

Beyond biomarkers: How enhanced CT imaging can improve the diagnostic-driven management of invasive mould disease.

CT imaging remains an essential diagnostic test for identification, staging and management of invasive mould infection (IMI) in patients with hematological malignancies. Yet the limited specificity of standard CT imaging can drive excessive antifungal use in patients, especially when more definitive diagnosis cannot be established through microbiology or invasive diagnostic procedures. CT pulmonary angiography (CTPA) is a complimentary, non-invasive approach to standard CT that allows for direct visualization of pulmonary arteries inside infiltrates for signs of angioinvasion, vessel destruction and vessel occlusion. Experience from several centers that are using CTPA as part of a standard diagnostic protocol for IMI suggests that a positive vessel occlusion sign (VOS) is the most sensitive and a specific sign of IMI in both neutropenic and non-neutropenic patients. CTPA is particularly useful in patients who develop suspected breakthrough IMI during antifungal prophylaxis because, unlike serum and/or BAL galactomannan and polymerase chain reaction (PCR) testing, the sensitivity is not reduced by antifungal therapy. A negative VOS may also largely rule-out the presence of IMI, supporting earlier discontinuation of empirical therapy. Future imaging protocols for IMI in patients with hematological malignancies will likely replace standard chest X-rays in favor of early low radiation dose CT exams for screening, with characterization of the lesions by CTPA and routine follow-up using functional/metabolic imaging such as 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (FDG-PET/CT) to assess treatment response. Hence, enhanced CT imaging techniques can improve the diagnostic-driven management of IMI management in high-risk patients with hematological malignancies.