J Neurol Res

Journal of Neurology Research, ISSN 1923-2845 print, 1923-2853 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Neurol Res and Elmer Press Inc

Journal website https://www.neurores.org

Case Report

Volume 10, Number 5, October 2020, pages 199-202

Brain Abscess in a Patient With Radiotherapy-Treated Adenoid Cystic Carcinoma: A Misdiagnosis Case Report and Review of the Literature

Figure 1. (a) Computed tomography of the head with and without contrast demonstrating left temporal lobe vasogenic edema. (b) Magnetic resonance imaging of the brain with and without contrast, diffusion weighted imaging demonstrating a well-circumscribed lesion to the left temporal lobe. (c) Magnetic resonance imaging of the brain with and without contrast, flair images demonstrating vasogenic edema to the left temporal lobe.

**Table 1.** Summary of Retrospective Studies, Case Series, and Case Reports Related to Abscesses Arising After Radiation Therapy
Authors	Type of study	Key findings
NPC: nasopharyngeal cancer; CNS: central nervous system.
Chuang et al, 2015 [3]	Retrospective study of 146 patients with brain abscesses (10 of whom had received radiotherapy for a head and neck cancer).	The pathogenesis of bacterial brain abscess in post-irradiated NPC patients is likely due to radiation and the tumor both destroyed the skull base and resulted in a breakdown of the blood-brain barrier, providing a pathway for the pathogens; increase in the incidence of chronic otitis media, sphenoid sinusitis, or other nasal infection. Radiation-related temporal lobe necrosis is also a predisposing factor.
Fang et al, 2012 [4]	Retrospective analysis of 210 patients with brain abscesses, 12 of whom had radiotherapy-treated NPC.	NPC patients post radiotherapy with brain abscesses frequently had chronic otitis media; temporal lobe as the most common site; high incidence of post-radiation necrosis; staphylococcus and streptococcus as the most common species.
Liang et al, 2009 [5]	Retrospective study of 18 post-irradiated NPC patients with CNS infection (brain abscess, cavernous sinus thrombosis, epidural abscess, and meningitis).	Post-irradiated NPC patients with skull base osteoradionecrosis are prone to have CNS infections. The prevalence of otitis media and rhinosinusitis is high in post-irradiated NPC patients. Ten patients with CNS infection had skull base osteoradionecrosis.
Cheng et al, 2000 [8]	Six cases of brain abscesses in patient with radiotherapy-treated NPC.	Radiation necrosis in the temporal lobe can be a side-effect of NPC treated with radiotherapy. History of nasal infection or otitis media was recognized in all six patients. A bony defect was observed between the middle cranial fossa and the sphenoid sinus in three patients.
Kuriyama et al, 2019 [9]	Case report of a patient with scalp angiosarcoma and a subsequent brain abscess after treatment.	Brain abscess formation in this patient could be due to large skin defects and cranial bone necrosis resulting from surgery and radiation.
Noguchi et al, 2018 [10]	Case report of oropharyngeal carcinoma treated with radiotherapy and with a subsequent brain abscess several years later.	Patient underwent chemoradiotherapy for oropharyngeal carcinoma. Was later found to have brain abscess that was presumed to be caused by radiation osteomyelitis of the mandible.

Table 1. Summary of Retrospective Studies, Case Series, and Case Reports Related to Abscesses Arising After Radiation Therapy

Authors

Type of study

Key findings

NPC: nasopharyngeal cancer; CNS: central nervous system.

Chuang et al, 2015 [3]

Retrospective study of 146 patients with brain abscesses (10 of whom had received radiotherapy for a head and neck cancer).

The pathogenesis of bacterial brain abscess in post-irradiated NPC patients is likely due to radiation and the tumor both destroyed the skull base and resulted in a breakdown of the blood-brain barrier, providing a pathway for the pathogens; increase in the incidence of chronic otitis media, sphenoid sinusitis, or other nasal infection. Radiation-related temporal lobe necrosis is also a predisposing factor.

Fang et al, 2012 [4]

Retrospective analysis of 210 patients with brain abscesses, 12 of whom had radiotherapy-treated NPC.

NPC patients post radiotherapy with brain abscesses frequently had chronic otitis media; temporal lobe as the most common site; high incidence of post-radiation necrosis; staphylococcus and streptococcus as the most common species.

Liang et al, 2009 [5]

Retrospective study of 18 post-irradiated NPC patients with CNS infection (brain abscess, cavernous sinus thrombosis, epidural abscess, and meningitis).

Post-irradiated NPC patients with skull base osteoradionecrosis are prone to have CNS infections. The prevalence of otitis media and rhinosinusitis is high in post-irradiated NPC patients. Ten patients with CNS infection had skull base osteoradionecrosis.

Cheng et al, 2000 [8]

Six cases of brain abscesses in patient with radiotherapy-treated NPC.

Radiation necrosis in the temporal lobe can be a side-effect of NPC treated with radiotherapy. History of nasal infection or otitis media was recognized in all six patients. A bony defect was observed between the middle cranial fossa and the sphenoid sinus in three patients.

Kuriyama et al, 2019 [9]

Case report of a patient with scalp angiosarcoma and a subsequent brain abscess after treatment.

Brain abscess formation in this patient could be due to large skin defects and cranial bone necrosis resulting from surgery and radiation.

Noguchi et al, 2018 [10]

Case report of oropharyngeal carcinoma treated with radiotherapy and with a subsequent brain abscess several years later.

Patient underwent chemoradiotherapy for oropharyngeal carcinoma. Was later found to have brain abscess that was presumed to be caused by radiation osteomyelitis of the mandible.