Difficulty of diagnosing a mucor-induced aneurysm arising in segment P4 of the posterior cerebral artery – A case report

Abstract

Background: Identification of causative pathogen for fungal aneurysm is frequently difficult. We reported the case of a fungal aneurysm caused by Mucor arising in segment P4 of the posterior cerebral artery (PCA) detected only by histopathological examination. Case Description: A 50-year-old female complained of nausea and vomiting. Computed tomography showed an intracranial hemorrhage in the left occipital lobe and acute hydrocephalus due to intraventricular hemorrhaging. Digital subtraction angiography performed after external drainage showed a cerebral aneurysm in segment P4 of the left PCA. Surgical excision of the aneurysm and end-to-end anastomosis of the PCA were performed. A histopathological examination revealed that the aneurysm had been caused by a Mucor infection. Conclusion: In fungal aneurysm cases, especially those involving Mucor infections, it is difficult to identify the causative fungal infection based on cultures, imaging, and serological tests. Therefore, surgical excision and histopathological diagnosis are important for diagnosing such cases if possible.

Fungal symptomatic intracranial aneurysm treated with a flow diverting stent: A case report

“…IIA often occurs in patients with conditions such as poorly controlled diabetes mellitus, leukemia, ongoing chemotherapy, or steroid therapy. [ 7 , 9 , 13 , 17 , 18 , 31 ] The present case had no pre-existing diabetes mellitus and was not on steroids. Although she had recently undergone treatment for breast cancer, she received surgical resection and hormone therapy only, with no chemotherapy.…”

“…However, in some cases, patients have negative results for various examinations. For example, blood cultures may be negative[ 3 , 7 , 17 , 29 ] multiple times,[ 24 ] as can be urine, sputum,[ 24 ] spinal fluid, and ascitic cultures. [ 29 ] It has been reported that 12.7% of patients with IIA have negative results for blood cultures.…”

“…[ 29 ] It has been reported that 12.7% of patients with IIA have negative results for blood cultures. [ 3 ] Some cases of intracranial fungal aneurysm have C-reactive protein levels and white blood cell counts within a normal range[ 17 , 18 ], and some show negative results for β-d-glucan or aspergillus antigen. [ 7 , 17 ] After resection of intracranial fungal aneurysms, histopathologic findings may directly demonstrate the existence of fungus, for example, by detecting coenocytic hyphae.…”

“…[ 3 ] Some cases of intracranial fungal aneurysm have C-reactive protein levels and white blood cell counts within a normal range[ 17 , 18 ], and some show negative results for β-d-glucan or aspergillus antigen. [ 7 , 17 ] After resection of intracranial fungal aneurysms, histopathologic findings may directly demonstrate the existence of fungus, for example, by detecting coenocytic hyphae. [ 17 ] However, in some cases, only the thickening or destruction of vessel walls is detected.…”

“…[ 26 ] Treatments for fungal IIA remain controversial, and many different approaches have been used. Surgical treatments include trapping,[ 31 ] excision,[ 17 ] and clipping,[ 4 , 20 , 22 ] whereas endovascular treatments include coiling,[ 8 , 10 ] placing of a detachable balloon,[ 8 ] and liquid embolization. [ 8 ] However, the endovascular treatment of fungal IIA using a flow-diverting stent has rarely been reported.…”