Imaging findings in intracranial aspergillus infection in immunocompetent patients

A Rare Case of Invasive Central Nervous System Aspergillus niger in a Previously Immunocompetent Patient After Corticosteroid Treatment for COVID-19

Aspergillus is a ubiquitous saprophyte found in air, soil, and organic matter. Humans inhale the spore form of the fungus, but manifestations of the disease are typically predominantly seen in immunocompromised patients. Invasive central nervous system (CNS) aspergillosis is even more uncommon, and epidemiological data is sparse, particularly in immunocompetent patients. We report the case of a 67-year-old previously immunocompetent female with no known comorbidities who was treated with corticosteroids for COVID-19 one month prior to admission for altered mental status (AMS). Subsequent imaging and biopsy demonstrated invasive CNS Aspergillus niger. Though a rare cause of AMS in immunocompetent patients, this report draws attention to the detrimental immunosuppressive effects of corticosteroid therapy in COVID-19.

Expansile Sphenoid Mycetoma Presenting With Headache and Galactorrhea

This case report describes an immunocompetent woman in her 30s with daily vertex headaches over 13 months duration who developed spontaneous galactorrhea and was diagnosed with noninvasive fungal sinusitis.

Fatal Fungal Aneurysm Rupture Due to Aspergillosis after Craniopharyngioma Removal via Endoscopic Endonasal Surgery: Case Report and Comparison with Seven Reported Patients

There has been a noted increase in the incidence of intracranial aspergillosis; this is often attributed to the wider use of antibiotics, corticosteroids, and immunosuppressants. Fungal cerebral aneurysms due to aspergillosis after neurosurgery remain extremely rare; in fact, only seven cases have been reported in the literature. In this study, we present a patient with an Aspergillus aneurysm that elicited subarachnoid hemorrhage after endoscopic endonasal surgery (EES) for craniopharyngioma. A 70-year-old woman with recurrent craniopharyngioma and steroid treatment underwent uneventful EES. On the 5th postoperative day, she suffered subarachnoid hemorrhage. As per her computed tomography angiography findings, an aneurysm was detected on the left internal carotid artery (ICA). Subsequent digital subtraction angiography showed occlusion of the ICA and an irregularly shaped wall. The diagnosis was pseudoaneurysm. We then performed craniotomy to place a left high-flow bypass and to trap the pseudoaneurysm. Despite continuous intensive care, she died on the 25th postoperative day of a huge, left cerebral infarct. The final diagnosis was made at autopsy; it revealed destruction of the ICA and Aspergillus invasion of the vessel wall, confirming the presence of a true fungal aneurysm. Perioperatively, patients with potential immunosuppression must be carefully managed. Advanced age is a risk factor. As surgery via the paranasal sinuses raises the risk for aspergillosis, fungal infection must be ruled out in patients whose postoperative course is deemed concerning.

Intracranial aspergillosis in immunocompetent adult patients without risk factors: a systematic review

The clinical features and prognostic factors of intracranial aspergillosis in immunocompetent patients without risk factors are not well known. PubMed, Scopus, Google Scholar, and Web of Science were searched for all relevant case reports/series on adult patient (≥ 18 years) with aspergillosis published from 1976 to 2018. One hundred eighty-two patients (median age, 40 years; range, 18-83 years; male:female, 115:67) were identified. Types of intracranial aspergillosis included intracranial mass from the skull base (54.9%), pure intraparenchymal disease (23.6%), meningoencephalitis (13.2%), and dural-based mass (8.2%). Vascular complications occurred in 44 patients (26.3%). Eighty-one patients (44.5%) had favourable final clinical outcomes without any deficits, whereas 58 (31.9%) died. Disease-related mortality improved significantly over time (43.1% [28/65] before 2000, 25.9% [30/116] after 2001; p = 0.021). Patients with meningoencephalitis demonstrated the highest mortality rate (79.2%, 19/24). Medical non-responders (patients whose disease course worsened after receiving the initial medication regimen) and vascular complications (the presentation of subarachnoid haemorrhage, intracerebral haemorrhage, or infarction related to the rupture or occlusion of intracranial vessels) were significantly associated with mortality (p < 0.001). Findings from the current review may help predict patient prognosis at the initial assessment and determine potential prognostic factors.

Invasive sphenoid sinus aspergillosis mimicking sellar tumor: a report of 4 cases and systematic literature review

Background

Invasive sphenoid sinus aspergillosis is a rare but life-threatening condition usually found in immunocompromised patients. When involving cavernous sinus and surrounding structures, patients are frequently misdiagnosed with a neoplasm or sellar abscess. Timely diagnosis and intervention are crucial to patients’ outcomes. The objective of this study is to review cases of invasive sphenoid sinus aspergillosis to describe disease manifestations, imaging features, treatment, and outcome.

Case presentation

We describe four patients with invasive sphenoid sinus aspergillosis misdiagnosed as sellar tumors preoperatively. The mass was completely removed in three patients and partially removed in one patient microscopically. Pathological examinations confirmed Aspergillus in all cases. All four patients received anti-fungal agents postoperatively. There was no recurrence at the time of each patient’s follow-up date. One patient with complete resection was lost to follow-up while the other three patients’ neurologic function improved. Additionally, we performed a systematic review regarding invasive sphenoid sinus aspergillosis of existing English literature.

Conclusion

With regard to clinical symptoms, headache, vision impairment, and ophthalmoplegia were observed in over half of the patients in the literature. A sellar mass with bone destruction on CT and involvement of cavernous sinus is highly suggestive of invasive fungal sphenoid sinusitis. Immediate surgical removal of the lesion is recommended for invasive sphenoid sinus aspergillosis to preserve nerve function and increase the likelihood of survival.

Role of Voriconazole in the Management of Invasive Central Nervous System Aspergillosis: A Case Series from a Tertiary Care Centre in India

Invasive central nervous system (CNS) aspergillosis is acquired by either hematogenous dissemination or direct spread from a sinus infection. We describe a series of nine patients with CNS aspergillosis from a tertiary care teaching institute in North India who were treated with voriconazole alone or in combination with surgery. All patients who had clinical and radiological features consistent with fungal CNS infection, showed the presence of septate hyphae on histopathology/microscopy and were either culture positive for Aspergillus spp. or had serum galactomannan positivity were diagnosed as CNS aspergillosis. Clinical features, risk factors, diagnostic modalities, treatment details and outcome at last follow-up were recorded for all patients diagnosed with CNS aspergillosis. A total of nine patients were diagnosed with CNS aspergillosis. The median duration of presentation at our hospital was six months (IQR-2-9 months). Six patients had concomitant sinus involvement, while two patients had skull-base involvement as well. All patients were treated with voriconazole therapy, and three of these patients underwent surgery. All but one patient survived at the last follow-up (median duration was 14 months (IQR- 8-21.5). Two patients had complete resolution, and voriconazole was stopped at the last follow-up, and the rest of the patients were continued on voriconazole. Of the six patients who were continued on voriconazole, all but one had more than 50% radiological resolution on follow-up imaging. Invasive CNS aspergillosis is an important cause of CNS fungal infection that is often diagnosed late and requires long-term voriconazole-based therapy.

Diagnosis and treatment of invasive fungal infections: looking ahead

Improved standards of care depend on the development of new laboratory diagnostic and imaging procedures and the development of new antifungal compounds. Immunochromatography technologies have led to the development of lateral flow devices for the diagnosis of cryptococcal meningitis and invasive aspergillosis (IA). Similar devices are being developed for the detection of histoplasmosis that meet the requirements for speed (∼15 min assay time) and ease of use for point-of-care diagnostics. The evolution of molecular tools for the detection of fungal pathogens has been slow but the introduction of new nucleic acid amplification techniques appears to be helpful, for example T2Candida. An Aspergillus proximity ligation assay has been developed for a rapid near-patient bedside diagnosis of IA. CT remains the cornerstone for radiological diagnosis of invasive pulmonary fungal infections. MRI of the lungs may be performed to avoid radiation exposure. MRI with T2-weighted turbo-spin-echo sequences exhibits sensitivity and specificity approaching that of CT for the diagnosis of invasive pulmonary aspergillosis. The final part of this review looks at new approaches to drug discovery that have yielded new classes with novel mechanisms of action. There are currently two new classes of antifungal drugs in Phase 2 study for systemic invasive fungal disease and one in Phase 1. These new antifungal drugs show promise in meeting unmet needs with oral and intravenous formulations available and some with decreased potential for drug-drug interactions. Novel mechanisms of action mean these agents are not susceptible to the common resistance mechanisms seen in Candida or Aspergillus. Modification of existing antifungal susceptibility testing techniques may be required to incorporate these new compounds.

Holohemispheric Invasive Aspergillus Granulomatous Cerebritis of the Brain

BACKGROUND

Invasive aspergillosis of the central nervous system, a saprophytic infection with a unique vascular tropism, carries the burden of increased morbidity and mortality. Early clinical and imaging findings can masquerade as an innocuous condition before a secondary inexorable progression. We highlight the clinical and imaging phenotype of a patient with fatal invasive granulomatous aspergillosis.

CASE DESCRIPTION

A 39-year-old man presented with progressive weakness of the left upper and lower limb for 4 months. Imaging demonstrated right holohemispheric extensive, numerous, confluent, ill-defined, T2 hypointense foci with moderate perilesional edema. Numerous foci of microhemorrhages with cortical asymmetric mineralization were seen. Post-contrast heterogeneous, variegate, punctiform enhancement of the lesions was observed extending to the ventricular margins. Volume loss of the left cerebral peduncle and ipsilateral long white matter descending tracts was noted. Histopathologic examination of a stereotactic biopsy specimen from the frontal region lesion showed dense inflammatory infiltrate with granulomas, a few in a perivascular distribution and branching septate hyphae resembling Aspergillus. The patient was initiated on antifungal therapy and in the following week, he had progressive drowsiness. The patient succumbed the next day.

CONCLUSIONS

Diffuse holohemispheric, progressive presentation of a granulomatous form of invasive aspergillosis is a rare entity. The miliary pattern of heterogenous enhancement, holohemispheric conglomerate T2 hypointensities, interspersed hemorrhage, juxtacortical punctate T2 hyperintense foci, low perfusion, and the relative absence of diffusion abnormality are distinctive features. Early diagnosis of this atypical imaging phenotype of Aspergillus infection and appropriate treatment is critical for better prognosis.

Intracranial fungal granuloma: a single-institute study of 90 cases over 18 years

OBJECTIVE

Intracranial fungal granuloma (IFG) remains an uncommon entity. The authors report a single-institute study of 90 cases of IFG, which is the largest study until now.

METHODS

In this retrospective study, all cases of IFG surgically treated in the years 2001-2018 were included. Data were obtained from the medical records and the pathology, microbiology, and radiology departments. All relevant clinical data, imaging characteristics, surgical procedure performed, perioperative findings, and follow-up data were recorded from the case files. Telephonic follow-up was also performed for a few patients to find out their current status.

RESULTS

A total of 90 cases consisting of 64 males (71.1%) and 26 (28.9%) females were evaluated. The mean patient age was 40.2 years (range 1-79 years). Headache (54 patients) was the most common presenting complaint, followed by visual symptoms (35 patients), fever (21 patients), and others such as limb weakness (13 patients) or seizure (9 patients). Cranial nerve involvement was the most common sign (47 patients), followed by motor deficit (22 patients) and papilledema (7 patients). The mean duration of symptoms before presentation was 6.4 months (range 0.06-48 months). Thirty patients (33.3%) had predisposing factors like diabetes mellitus, tuberculosis, or other immunocompromised status. A pure intracranial location of the IFG was seen in 49 cases (54.4%), whereas rhinocerebral or paranasal sinus involvement was seen in 41 cases (45.6%). Open surgery, that is, craniotomy and decompression, was performed in 55 cases, endoscopic biopsy was done in 30 cases, and stereotactic biopsy was performed in 5 cases. Aspergilloma (43 patients) was the most common fungal mass, followed by zygomycosis (13 patients), chromomycosis (9 patients), cryptococcoma (7 patients), mucormycosis (5 patients), and candida infection (1 patient). In 12 cases, the exact fungal phenotype could not be identified. Follow-up was available for 69/90 patients (76.7%). The mean duration of the follow-up was 37.97 months (range 3-144 months). The mortality rate was 52.2% (36/69 patients) among the patients with available follow-up.

CONCLUSIONS

A high index of suspicion for IFG should exist for patients with an immunocompromised status and diabetic patients with rhinocerebral mass lesions. Early diagnosis, aggressive surgical decompression, and a course of promptly initiated antifungal therapy are associated with a better prognosis.

Intracranial Fungal Infection After Solid-Organ Transplant

Neurologic complications after solid-organ transplant reveal a great spectrum of pathologies. Intracranial hemorrhages, cerebral ischemic lesions, infarctions, lymphoproliferative disorders, and infections, including aspergillosis, have been observed after liver transplant. Fungi constitute nearly 5% of all central nervous system infections, mainly occurring in immunocompromised patients. The most common causative agent is Aspergillus species. It presents either as maxillary sinusitis or pulmonary infection. Brain involvement of Aspergillus carries a high rate of mortality. Aspergillosis presents in the forms of meningitis, mycotic aneurysms, infarctions, and mass lesions. Aspergillosis does not have a specific radiologic appearance. Parenchymal aspergillosis has heterogenous signal intensity (hypointense on T1-weighted and hyperintense on T2-weighted images). Here, we present 3 patients who underwent solid-organ transplant and developed central nervous system aspergillosis. Different modalities of neurosurgical intervention were performed in combination with chemotherapy as part of their fungal therapy.

Tree-in-bud Appearance in the Brain: Fungal Granuloma on Contrast Magnetic Resonance Imaging

We describe a case of dural-based homogenously enhancing fungal granuloma in a 29-year-old male who presented with 3 months history of headache. The peculiarity of the case was that there were streaky areas of enhancement around the lesion in the brain parenchyma which resembled tree-in-bud like appearance. The patient underwent surgery and histopathological analysis revealed numerous Aspergillus hyphae. To the best of our knowledge, this is the first case report of a fungal granuloma with atypical parenchymal enhancement pattern.

The Effects of Paracoccidioides brasiliensis Infection on GM-CSF- and M-CSF-Induced Mouse Bone Marrow-Derived Macrophage from Resistant and Susceptible Mice Strains

Considering the importance of macrophages as the first line of defense against fungal infection and the different roles played by the two M1- and M2-like polarized macrophages, we decided to evaluate the effects of Paracoccidioides brasiliensis infection on GM-CSF- and M-CSF-induced bone marrow-derived macrophages (BMM) from the A/J and B10.A mouse strains, an established model of resistance/susceptibility to PCM, respectively. Upon differentiation, the generated GM- or M-BMMs were characterized by morphological analyses, gene expression profiles, and cytokines production. Our main results demonstrate that GM-BMMs derived from A/J and B.10 produced high levels of pro- and anti-inflammatory cytokines that may contribute to generate an unbalanced early immune response. In accordance with the literature, the B10.A susceptible mice lineage has an innate tendency to polarize into M1-like phenotype, whereas the opposite phenotype occurs in A/J resistance mice. In this context, our data support that susceptibility and resistance are strongly correlated with M1 and M2 polarization, respectively.

Malignant fungal infection of the cavernous sinus: case report

Intracranial spread of fungal infection is a life-threatening condition that usually affects immunocompromised patients. Here the authors present a case of biopsy-proven Aspergillus fumigatus infection of the paranasal sinuses in an immunocompetent patient with documented spread to the orbit, cavernous sinus, and petrous apex despite medical antifungal treatment. As a life-saving treatment, cavernous sinus resection with external carotid artery-middle cerebral artery bypass was performed. The authors discuss the literature regarding the intracranial spread of paranasal sinus fungal infections in immunocompetent patients and management strategies.