Cerebral Pseudallescheria boydii infection: unique occurrence of fungus ball formation in the brain

Unusual Fungal Endocarditis Causing Disseminated Infection After Renal Transplant

Fungal endocarditis is a relatively uncommon disease; it mostly affects those with intracardiac devices and those with compromised immune systems. Scedosporium apiospermum (S. apiospermum), the asexual state of Pseudoallescheria boydii, has become increasingly reported as an opportunistic pathogen. These filamentous fungi present in soil, sewage, and polluted waters, and was previously recognized to cause human infection after their inhalation or traumatic subcutaneous implantation. In immunocompetent individuals, it usually causes localized diseases depending on the site of entry such as skin mycetoma. However, in immunocompromised hosts, the fungus species appear to disseminate and cause invasive infections, frequently reported to be life-threatening with poor response to antifungal medications. S. apiospermum invasive endocarditis remains a rare complication, mostly cited in immunocompetent hosts with prosthetic cardiac valves or other intracardiac devices and severely immunocompromised patients with hematologic neoplasia. Herein, we describe the case of a renal transplant patient on immunosuppressive medications who presented with S. apiospermum fungal septic infection that invaded the left ventricular outflow tract (LVOT) causing endocarditis with disseminated infection and resulted in poor clinical outcome.

Infections caused by Scedosporium spp

Scedosporium spp. are increasingly recognized as causes of resistant life-threatening infections in immunocompromised patients. Scedosporium spp. also cause a wide spectrum of conditions, including mycetoma, saprobic involvement and colonization of the airways, sinopulmonary infections, extrapulmonary localized infections, and disseminated infections. Invasive scedosporium infections are also associated with central nervous infection following near-drowning accidents. The most common sites of infection are the lungs, sinuses, bones, joints, eyes, and brain. Scedosporium apiospermum and Scedosporium prolificans are the two principal medically important species of this genus. Pseudallescheria boydii, the teleomorph of S. apiospermum, is recognized by the presence of cleistothecia. Recent advances in molecular taxonomy have advanced the understanding of the genus Scedosporium and have demonstrated a wider range of species than heretofore recognized. Studies of the pathogenesis of and immune response to Scedosporium spp. underscore the importance of innate host defenses in protection against these organisms. Microbiological diagnosis of Scedosporium spp. currently depends upon culture and morphological characterization. Molecular tools for clinical microbiological detection of Scedosporium spp. are currently investigational. Infections caused by S. apiospermum and P. boydii in patients and animals may respond to antifungal triazoles. By comparison, infections caused by S. prolificans seldom respond to medical therapy alone. Surgery and reversal of immunosuppression may be the only effective therapeutic options for infections caused by S. prolificans.

Eumycetoma presenting as a cerebellopontine angle mass lesion

Eumycetoma in the cerebellopontine angle region is extremely uncommon with no case being reported as per an extensive review of the literature by the authors. The authors report a case of cerebellopontine angle eumycetoma in a young female managed by subtotal decompression and antifungal treatment. The pre-operative diagnosis of eumycetoma in this location is extremely difficult and the role of histopathology is very important to characterize this uncommon lesion. The prognosis of this bizarre pathology is dismal despite all treatment modalities as compared to the usual tumors of the cerebellopontine angle that generally have a favorable outcome.

Scedosporium apiospermum: changing clinical spectrum of a therapy-refractory opportunist*

Current knowledge on the opportunist Scedosporium apiospermum (teleomorph: Pseudallescheria boydii), generated over a period of more than 120 years, is reviewed. The natural environmental habitat of the fungus is unknown; nutrient-rich, brackish waters like river estuaria have been suggested. The fungus is strongly promoted by agricultural and particularly by industrial pollution.

An immunocompetent patient with primary Scedosporium apiospermum vertebral osteomyelitis

Scedosporium apiospermum, the asexual anamorph of Pseudallescheria boydii, is a ubiquitous saprophytic fungus that usually causes cutaneous/subcutaneous infection but may manifest as an invasive disease, often in immunocompromised hosts. Following an extensive literature review, we think that this case represents the first documented report of a primary infection of the spine in an immunocompetent patient. Despite extensive surgical debridement and itraconazole therapy, the patient died of multisystem organ failure of unknown etiology. Our case and three previously reported cases of P. boydii vertebral osteomyelitis highlight the importance of obtaining repeat cultures in patients with culture-negative vertebral osteomyelitis who fail to adequately respond to empiric standard antibacterial and/or antimycobacterial therapy. Combined surgical debridement and antifungal therapy have been required for eradication of P. boydii spinal infections in two previously reported immunocompromised patients, although the optimal antifungal regimen for this infection has not been established.

Pseudallescheria boydii brain abscess successfully treated with voriconazole and surgical drainage: case report and literature review of central nervous system pseudallescheriasis

Pseudallescheria boydii and its asexual form, Scedosporium apiospermum, are ubiquitous, saprophytic fungi that commonly cause cutaneous infection. However, in certain circumstances, P. boydii can also cause invasive disease, which can involve the central nervous system (CNS). When the CNS becomes involved, treatment is difficult, therapeutic options are limited, and the prognosis is poor. We report a case of Pseudallescheria brain abscess successfully treated with surgical drainage and systemic voriconazole, the first such case to be described in the literature. We also review previously reported cases of CNS pseudallescheriasis and evaluate therapeutic options.

Pathology of hyalohyphomycosis caused by Scedosporium apiospermum (Pseudallescheria boydii): an emerging mycosis

The genus Scedosporium contains two medically significant species of emerging mycotic agents, S. apiospermum and S. prolificans, which have received scant attention. Scedosporium apiospermum is the anamorph, or asexual state, of the cosmopolitan fungus Pseudallescheria boydii, with both sharing the same risk factors for infection, clinical spectrum, and histopathologic features. Scedosporium prolificans is a recently recognized agent of bone, soft tissue, and joint infections that occurs with highest frequency in children and young adults. S. prolificans may also cause potentially fatal disseminated infections in immunocompromised persons. The drug sensitivities of both Scedosporium species are significantly different from those of most other fungi, and thus identification of these organisms is important. Unfortunately, the pathological features of Scedosporium infections may be easily confused with other mycotic agents, resulting in delayed or inappropriate medical therapy. Because many pathologists and clinicians are unfamiliar with the significance of Scedosporium spp. infection, this communication describes three persons with differing clinical and pathological presentations of S. apiospermum infection. In one patient with sickle cell disease and chronic mycotic sinusitis, fungal colonies of S. apiospermum removed from the sinuses showed a pattern of alternating zones of mycelial hypercellularity and hypocellularity associated with conidiation, similar to a previous report of P. boydii infection. The clinicopathologic features of an immunocompetent person with S. apiospermum osteomyelitis, and a patient with S. apiospermum infection of the brain after bone marrow transplantation, are also described.

Monosporium apiospermum meningoencephalitis: a clinico-pathological case

Twenty nine cases of central nervous system infection due to Monosporium apiospermum have been reported. Six of them occurred after an aspiration pneumonia following a near drowning. The case of a 53 year old man is reported: M apiospermum was isolated from cerebrospinal fluid, sputum, urine and from the mud of the ditch where the patient had fallen. Though the treatment used recommended doses of intravenous, intrathecal and intraventricular amphotericin B, it was ineffective and the patient died 97 days after the near drowning. Necropsy showed that the ventricular infectious process was more prominent distant from the antifungal ventricular source.