Outcomes of persons with blastomycosis involving the central nervous system

Disseminated blastomycosis with an intracranial fungoma in an immunocompetent patient: illustrative case

BACKGROUND

Blastomyces dermatitidis is a fungus endemic to central and southern North America. While infection most commonly results in pneumonia, a small number of infections progress to systemic disease, which may include intracranial lesions. Progression to systemic disease is most common in immunocompromised patients, such as those with human immunodeficiency virus.

OBSERVATIONS

The authors present a 44-year-old immunocompetent male who presented following a tonic-clonic seizure. Initial workup revealed a 19-mm enhancing intracranial mass. There was avid uptake of fluorescein sodium, and an en bloc resection of the mass was performed. Histopathology revealed B. dermatitidis. Medical management included amphotericin B and azole therapy. Postoperative recovery was uneventful, and no focal neurological deficits were appreciated.

LESSONS

This case highlights the neurosurgical management of a rare intracranial fungal manifestation in an immunocompetent patient. A literature review was also performed to better understand the role of neurosurgery in fungal infections. There were limited cases of intracranial Blastomyces reported in immunocompetent patients, and neurosurgical management varied (no intervention, biopsy, resection) and was underreported. Too few cases are reported to suggest neurosurgical intervention for blastomycosis improves outcomes. Medical management was relatively standard with azole and amphotericin therapy.

Granulomatous Diseases of the Central Nervous System

PURPOSE OF REVIEW

To discuss the pathophysiology, key clinical features, necessary diagnostic evaluation, and current treatment regimens for granulomatous diseases of the central nervous system.

RECENT FINDINGS

The diagnosis and management of granulomatous disease of the central nervous system has been revolutionized by advances in diagnostic imaging. Nevertheless, tissue and/or cerebrospinal fluid (CSF) sampling remains necessary to establish the diagnosis in most cases. Establishing a specific diagnosis is critical because treatment selection needs to focus on the granulomatous process centering on either antibiotic or immunosuppressive agents. Particular for non-infectious granulomatous disease more aggressive immunotherapies may help in clinical outcome. There are multiple non-infectious and infectious etiologies for granulomatous disease of the central nervous system. Clinical manifestations result from local structural invasion of granulomas or granulomatous inflammation of the blood vessels and meninges. Rapid diagnosis and specific treatment is essential.

Central nervous system blastomycosis clinical characteristics and outcomes

Blastomycosis is a local or systemic infection, caused by Blastomyces dermatitidis (B. dermatitidis) or B. gilchristii. Blastomycosis has been described as "the great pretender," alluding to the fact that it manifests in a wide range of symptoms and disease severity. Central nervous system (CNS) involvement, although rare, carries significant mortality. Due to the limited published reports of CNS blastomycosis, we present an updated cohort with eight cases of proven or probable CNS blastomycosis describing presentation, diagnosis, treatment and outcomes. Headache was the most common presenting symptom. Magnetic resonance imaging (MRI) proved to be the superior imaging study. All patients in our cohort were diagnosed by histopathological staining or cultures of tissue or fluid obtained from CNS or extra-CNS lesions. All patients that received treatment with Liposomal amphrotericin B for at least 10 days followed by a prolonged azole therapy did not have relapse. Two patients with late diagnoses died during hospitalization. Our findings confirm the importance of timely diagnosis and treatment of CNS blastomycosis to improve outcomes especially with an azole that have a high CNS penetration and a good intrinsic activity for B. dermatitidis such as voriconazole.

Blastomycosis

Blastomycosis is the fungal disease caused by thermally dimorphic fungi in the genus Blastomyces, with B dermatitidis complex causing most cases. It is considered hyperendemic in areas adjacent to the Great Lakes and along the St. Lawrence, Mississippi, and Ohio rivers, but definitive geographic distribution of blastomycoses remains obscure. Clinical presentation is variable. Disseminated blastomycosis with extrapulmonary manifestations is more common in immunosuppressed individuals. Culture positivity is required for definitive diagnosis, but compatible histology is often sufficient for presumptive diagnosis and initiation of treatment. Treatment should be provided to all symptomatic cases to prevent progression or recurrence.

Methods for rapid diagnosis of meningitis etiology in adults

Infectious meningitis can be caused by viral, bacterial or fungal pathogens. Despite widely available treatments, many types of infectious meningitis are still associated with significant morbidity and mortality. Delay in diagnosis contributes to poor outcomes. Cerebrospinal fluid cultures have been used traditionally but are time intensive and sensitivity is decreased by empiric treatment prior to culture. More rapid techniques such as the cryptococcal lateral flow assay (IMMY), GeneXpert MTB/Rif Ultra (Cepheid) and FilmArray multiplex-PCR (Biofire) are three examples that have drastically changed meningitis diagnostics. This review will discuss a holistic approach to diagnosing bacterial, mycobacterial, viral and fungal meningitis.

Central Nervous System Blastomycosis With Multiple Brain Abscesses Presenting as Right Upper Extremity Weakness

Blastomycosis is a mycotic infection that typically affects the lung, but that can have dermatologic, orthopedic, genitourinary, and central nervous system manifestations. Blastomyces dermatitidis is a true human pathogen, which can produce disease in immunocompetent hosts. Risk factors for infection include residence in or travel to endemic areas and outdoor occupation, particularly those activities near open bodies of water and that disrupt soil. Immunosuppressed patients are also at increased risk for severe and disseminated disease. We present a case of a 79-year-old male who presented with a 2-week history of progressive right upper extremity weakness and severe odontogenic disease. He was found to have multiple brain abscesses with positive cultures from a cerebral abscess incision and drainage for B dermatitidis. He underwent an incision and drainage of the largest cerebral abscess and was treated with intravenous liposomal amphotericin B, which he tolerated poorly. He was subsequently switched to voriconazole, which was well tolerated, and his neurological deficits improved throughout his hospitalization.

Disseminated blastomycosis presenting as a retro-orbital mass

A 43-year-old man with history of non-Hodgkins' lymphoma presented with unilateral eye swelling, pain and vision deficits which had been progressive over 2 months. Symptoms followed a presumed bacterial pneumonia 4 months prior. Imaging demonstrated retro-orbital soft tissue swelling with bony erosion concerning for a mass; surgical decompression was performed with histology confirming disseminated Blastomyces dermatitidis Symptoms responded rapidly to antifungal therapy with amphotericin followed by itraconazole. Orbital dissemination of blastomycosis is extremely rare; accurate diagnosis requires tissue biopsy to facilitate timely targeted therapy and minimise morbidity.

Central Nervous System Infection with Other Endemic Mycoses: Rare Manifestation of Blastomycosis, Paracoccidioidomycosis, Talaromycosis, and Sporotrichosis

The central nervous system (CNS) is not a major organ involved with infections caused by the endemic mycoses, with the possible exception of meningitis caused by Coccidioides species. When CNS infection does occur, the manifestations vary among the different endemic mycoses; mass-like lesions or diffuse meningeal involvement can occur, and isolated chronic meningitis, as well as widely disseminated acute infection that includes the CNS, are described. This review includes CNS infection caused by Blastomyces dermatitidis, Paracoccidioides brasiliensis, Talaromyces marneffei, and the Sporothrix species complex. The latter is not geographically restricted, in contrast to the classic endemic mycoses, but it is similar in that it is a dimorphic fungus. CNS infection with B. dermatitidis can present as isolated chronic meningitis or a space-occupying lesion usually in immunocompetent hosts, or as one manifestation of widespread disseminated infection in patients who are immunosuppressed. P. brasiliensis more frequently causes mass-like intracerebral lesions than meningitis, and most often CNS disease is part of disseminated infection found primarily in older patients with the chronic form of paracoccidioidomycosis. T. marneffei is the least likely of the endemic mycoses to cause CNS infection. Almost all reported cases have been in patients with advanced HIV infection and almost all have had widespread disseminated infection. Sporotrichosis is known to cause isolated chronic meningitis, primarily in immunocompetent individuals who do not have Sporothrix involvement of other organs. In contrast, CNS infection in patients with advanced HIV infection occurs as part of widespread disseminated infection.

Advances in the diagnosis and treatment of fungal infections of the CNS

Fungal infections of the CNS are challenging to treat and their optimal management requires knowledge of their epidemiology, host characteristics, diagnostic criteria, and therapeutic options. Aspergillus and Cryptococcus species predominate among fungal infections of the CNS. Most of these fungi are ubiquitous, but some have restricted geographical distribution. Fungal infections of the CNS usually originate from primary sites outside the CNS (eg, fungal pneumonia) or occur after inoculation (eg, invasive procedures). Most patients with these infections have immunodeficiencies, but immunocompetent individuals can also be infected through heavy exposure. The infecting fungi can be grouped into moulds, yeasts, and dimorphic fungi. Substantial progress has been made with new diagnostic approaches and the introduction of novel antifungal drugs, but fungal infections of the CNS are frequently lethal because of diagnostic delays, impaired drug penetration, resistance to antifungal treatments, and inadequate restoration of immune function. To improve outcomes, future research should advance diagnostic methods (eg, molecular detection and fungus identification), develop antifungal compounds with enhanced CNS-directed efficacy, and further investigate crucial host defence mechanisms.

Blastomycosis in Mammals

Blastomycosis is a serious fungal disease of dogs, humans, and occasionally other mammals caused by geographically restricted, thermally dimorphic Blastomyces species. Blastomycosis is primarily a canine disease, with approximately ten dogs diagnosed for every human case. Dogs also develop disease more rapidly, thus becoming sentinels for possible human disease. Human and canine blastomycosis may differ according to epidemiology/epizoology, clinical features, performance and use of diagnostics, and management.

Central nervous system blastomycosis diagnosed using the MVista® Blastomyces quantitative antigen enzyme immunoassay test on cerebrospinal fluid: A case report and review of the literature

Blastomyces dermatitidis is a thermally dimorphic fungus that is capable of causing pulmonary and extra-pulmonary disease, including infections of the central nervous system (CNS). Diagnosis of CNS blastomycosis with non-invasive testing can be difficult, and a surgical biopsy may ultimately be required for microbiological and/or histopathological confirmation. A case of B. dermatitidis meningitis is presented where the diagnosis was made by testing cerebrospinal fluid (CSF) using the MVista® Blastomyces Quantitative Antigen Enzyme Immunoassay test. The utility of performing this test on CSF for diagnosis of CNS mass lesions/abscesses caused by B. dermatitidis in the absence of associated meningitis remains unclear. Cross reaction of the Blastomyces antigen test with other dimorphic fungi is a concern, necessitating that positive test results are interpreted in the context of the patient's exposure and travel history.

Central Nervous System Blastomycosis in Children: A Case Report and Review of the Literature

We present a 7-year-old boy with chronic meningitis caused by Blastomyces dermatitidis. A review of the literature revealed 32 cases of central nervous system blastomycosis in children between 1983 and 2016, of which 18 represented parenchymal disease of the brain or spinal cord. Blastomycosis affecting the central nervous system is rare but should be considered in children with chronic meningitis.

Blastomycosis in Children: An Analysis of Clinical, Epidemiologic, and Genetic Features

BACKGROUND

Blastomyces spp. are endemic in regions of the United States and result in blastomycosis, a serious and potentially fatal infection. Little is known about the presentation, clinic course, epidemiology, and genetics of blastomycosis in children.

METHODS

A retrospective review of children with blastomycosis confirmed by culture or cytopathology between 1999 and 2014 was completed. Blastomyces sp. isolates were genotyped by using microsatellite typing, and species were typed by sequencing of internal transcribed spacer 2 (its2).

RESULTS

Of the 114 children with blastomycosis identified, 79% had isolated pulmonary involvement and 21% had extrapulmonary disease. There were more systemic findings, including fever (P = .01), poor intake (P = .01), elevated white blood cell count (P < .01), and elevated C-reactive protein level (P < .01), in children with isolated pulmonary disease than in children with extrapulmonary disease. Children with extrapulmonary disease had more surgeries (P = .01) and delays in diagnosis (P < .01) than those with isolated pulmonary infection. Of 52 samples genotyped, 48 (92%) were Blastomyces gilchristii and 4 (8%) were Blastomyces dermatitidis.

CONCLUSION

This is the first large-scale study of the clinical, epidemiologic, and genetic features of blastomycosis in children. The majority of the children had isolated pulmonary disease with systemic findings. Patients with extrapulmonary disease were less likely to have systemic symptoms or additional laboratory evidence of infection, which made delays in diagnosis more common. More than 90% of the pediatric cases were caused by B gilchristii.

Blastomycosis during pregnancy: a case report and review of the literature

The diagnosis of blastomycosis during pregnancy is rare, but can carry significant clinical questions for both the infected mother and developing fetus. Furthermore, given its rarity, providers have little available data to help manage and counsel patients in this uncommon, yet serious, scenario. We present a case of blastomycosis in a woman at 38weeks' gestation and review all published cases of blastomycosis during pregnancy. It is our hope to provide a multidisciplinary understanding of the current knowledge surrounding the presentation, diagnosis, management, and outcome of this unusual infection.

Blastomyces Antigen Detection for Diagnosis and Management of Blastomycosis

Blastomyces spp. antigen testing was evaluated over a 10-year period in an area where blastomycosis is endemic. Antigen testing was less sensitive than previously reported, but serial urine testing was useful in monitoring disease resolution or progression. Culture and cytopathology remain the gold standard for diagnosis and exclusion of this infection.

Infectious causes of stroke

Most infectious pathogens have anecdotal evidence to support a link with stroke, but certain pathogens have more robust associations, in which causation is probable. Few dedicated prospective studies of stroke in the setting of infection have been done. The use of head imaging, a clinical standard of diagnostic care, to confirm stroke and stroke type is not universal. Data for stroke are scarce in locations where infections are probably most common, making it difficult to reach conclusions on how populations differ in terms of risk of infectious stroke. The treatment of infections and stroke, when concomitant, is based on almost no evidence and requires dedicated efforts to understand variations that might exist. We highlight the present knowledge and emphasise the need for stronger evidence to assist in the diagnosis, treatment, and secondary prevention of stroke in patients in whom an infectious cause for stroke is probable.