Fatal Curvularia brain abscess in a heart and kidney transplant recipient

Abstract

A 42-year-old woman with history of heart failure status post orthotopic heart transplant and end stage renal disease presented to the hospital with decompensated heart failure that progressed to cardiogenic shock. She underwent a new orthotopic heart transplant and cadaveric donor kidney transplant. Three weeks later, she experienced right facial droop and right upper extremity weakness. Computed tomography showed a left frontal cortical lesion with vasogenic edema and a central hemorrhagic component. Given the concern for an angioinvasive mold infection, she was started on voriconazole and amphotericin B. Brain biopsy was performed and histopathology revealed septated hyphae with acute angle branching. Mycology culture isolated Curvularia sp. Unfortunately, her mental status deteriorated with subsequent development of multiorgan failure that led to death.

A 42-year-old woman with history of heart failure status post orthotopic heart transplant and end stage renal disease presented to the hospital with decompensated heart failure that progressed to cardiogenic shock. She underwent a new orthotopic heart transplant and cadaveric donor kidney transplant. Post-operatively, she developed pneumonia and bacteremia secondary to multidrug resistant Pseudomona aeruginosa, for which she was treated with ceftolozane/tazobactam and colistin for 2 weeks. Five days later, she experienced right facial droop and right upper extremity weakness. Laboratory studies revealed leukocytosis of 22.3 K/uL. Computed tomography showed a left frontal cortical lesion with vasogenic edema and a central hemorrhagic component. Given the suspicion for septic emboli, ceftolozane/tazobactam was restarted. Micafungin and vancomycin were also added empirically.

To better characterize the cerebral lesion, a magnetic resonance imaging (MRI) was ordered, which revealed a focal rounded area of hemorrhage within the left frontal lobe with a larger area of high flair and T2 signal intensity (Fig. 1A). These findings raised the concern for an angioinvasive mold infection. Micafungin was discontinued and the patient was started on voriconazole and amphotericin B. Her mental status deteriorated over the next 4 days and follow-up imaging demonstrated enlargement of the frontal lesion with mass effect and rightward midline shift (Fig. 1B). Brain biopsy was performed and histopathology revealed septated hyphae with acute angle branching (Fig. 2A). Subsequently, mycology culture isolated Curvularia sp. (Fig. 2B). This fungus was identified by morphologic characterization. Unfortunately, the patient’s mental status continued to decline with subsequent development of multiorgan failure that led to death.

Fig. 1.

A) Axial T2-weighted MRI showing a focal rounded area of hemorrhage within the left frontal lobe. B) Four days later, T2-weighted MRI demonstrated significant enlargement of hemorrhagic lesion with focal mass effect and new 4 mm rightward midline shift.

Fig. 2.

A) Histopathology of brain tissue showing septated hyphae with acute angle branching (Hematoxylin and eosin stain, x400). B) Microscopic examination showing blue-stained hyphae (arrow) and macroconidia of cultured Curvularia (Lactophenol cotton blue stain, x400).

Curvularia is a pigmented filamentous fungus found ubiquitously in soil. It has been rarely implicated in human infections, but reports of endocarditis, skin infections, keratitis, pneumonia, sinusitis and disseminated disease have been documented [1]. Brain abscess secondary to Curvularia is extremely uncommon, with only 8 cases reported in the literature [2]. This fungus invades the brain mostly by contiguous extension from paranasal sinuses; however, hematogenous dissemination or direct inoculation from penetrating trauma are also possible mechanisms [3]. In our patient, the MRI revealed involvement of paranasal sinuses, which likely served as the port of entry for this pathogen. The diagnosis is challenging and not always achieved by histopathology due to the similarities between Curvularia and Aspergillus. For this reason, tissue culture with morphologic or molecular identification is advocated at all times. The treatment is not standardized, but it includes surgical resection in combination with dual antifungal therapy [3]. Even with an aggressive approach, the mortality rate can be as high as 73% [4].

Declaration of Competing Interest

None of the authors reports a conflict of interest, and there were no funding sources.

Author statement

We had the following roles on this report:

First Author: Jose Armando Gonzales Zamora: Conceptualization and writing of the original draft.

Second Author: Yogeeta Varadarajalu: Writing review and edition of the manuscript.