Nocardia farcinica Brain Abscess: Report of 3 Cases

The Computed Tomography Findings and Follow-up Course of Pulmonary Nocardiosis

OBJECTIVE

Our study aimed to elucidate the computed tomography (CT) features and follow-up course of pulmonary nocardiosis patients to improve the understanding and diagnostic accuracy of this disease.

METHODS

The chest CT findings and clinical data of patients diagnosed with pulmonary nocardiosis by culture or histopathological examination in our hospital between 2010 and 2019 were retrospectively analyzed.

RESULTS

A total of 34 cases of pulmonary nocardiosis were included in our study. Thirteen patients were on long-term immunosuppressant therapy, among whom 6 had disseminated nocardiosis. Among the immunocompetent patients, 16 had chronic lung diseases or a history of trauma. Multiple or solitary nodules represented the most common CT feature (n = 32, 94.12%), followed by ground-glass opacities (n = 26, 76.47%), patchy consolidations (n = 25, 73.53%), cavitations (n = 18, 52.94%), and masses (n = 11, 32.35%). There were 20 cases (61.76%) with mediastinal and hilar lymphadenopathy, 18 (52.94%) with pleural thickening, 15 (44.12%) with bronchiectasis, and 13 (38.24%) with pleural effusion. Significantly higher rates of cavitations were observed among immunosuppressed patients (85% vs 29%, P = 0.005). At follow-up, 28 patients (82.35%) clinically improved with treatment, while 5 (14.71%) had disease progression, and 1 (2.94%) died.

CONCLUSIONS

Chronic structural lung diseases and long-term immunosuppressant use were found as risk factors for pulmonary nocardiosis. While the CT manifestations were highly heterogeneous, clinical suspicion should be raised upon findings of coexisting nodules, patchy consolidations, and cavitations, particularly in the presence of extrapulmonary infections such as those of the brain and subcutaneous tissues. A significant incidence of cavitations may be observed among immunosuppressed patients.

Nocardia Farcinica Mastoiditis and Epidural Abscess in an Immunocompetent Patient: A Rare Entity

Nocardia is regarded as an opportunistic pathogen primarily affecting the respiratory system, whereas Nocardia farcinica is the species of the Nocardia family that is most frequently blamed for central nervous system impairment. The authors present the first case of mastoiditis caused by Nocardia farcinica, accompanied by intracranial complications. An immunocompetent 74-year-old woman who reported a three-week left ear discharge and a two-week facial nerve palsy was referred to our department. MRI revealed mastoiditis and epidural abscess. The bacterial cultures obtained during the surgical management of the patient confirmed the presence of Nocardia farcinica. Targeted antibiotic therapy was subsequently administrated, gradually resulting in favourable outcomes. Nocardia species provoke a disseminated infection that emerges not only among the immunosuppressed individuals but can also affect the healthy population. The nonspecific clinical manifestations in addition to the difficulties identifying the pathogen, remain obstacles to a punctual diagnosis. However, the combination of surgical debridement and antibiotic treatment with trimethoprim and sulfamethoxazole is considered the most appropriate management, leading to propitious results.

Nocardia farcinica pituitary abscess in an immunocompetent patient: illustrative case

BACKGROUND

Pituitary abscess is a rare clinical entity, typically precipitated by Staphylococcus, Pseudomonas, or Aspergillus infection. Although Nocardia species–associated central nervous system abscesses have been documented in immunocompromised patients, no case of Nocardia pituitary abscesses has been previously reported.

OBSERVATIONS

A 44-year-old man presented with hemoptysis and was found to have a cavitary right lung nodule, which was presumed histoplasmosis, prompting antifungal treatment. Several months later, he developed panhypopituitarism. Magnetic resonance imaging identified a pituitary mass, which subsequently underwent transsphenoidal endoscopic biopsy. Infectious workup was negative, and the patient was discharged on intravenous ertapenem therapy. Over several months, he developed progressive headaches, and updated imaging confirmed interval enlargement of the mass with new cavernous sinus invasion. He underwent repeat endoscopic biopsy, which yielded positive cultures for Nocardia farcinica and prompted successful treatment with trimethoprim-sulfamethoxazole and linezolid.

LESSONS

The current study highlights a previously unreported clinical entity, the first pituitary abscess attributable to Nocardia sp. or N. farcinica, which arose in a young, immunocompetent individual. Although rare, atypical infections represent an important component in the differential diagnosis for sellar mass lesions.

Nocardia farcinica Brain Abscess in a Multiple Myeloma Patient Treated with Proteasome Inhibitor: A Case Report and Review of the Literature

Nocardia brain abscess is relatively rare, accounting for about 1–2% of all brain abscesses, and its mortality rate is three times higher than of other types of bacterial brain abscesses; thus, early diagnosis and treatment are essential. Nocardia brain abscess generally occurs in immunodeficient patients. We report a case of Nocardia farcinica brain abscess in a multiple myeloma patient treated with proteasome inhibitor (bortezomib and ixazomib), cyclophosphamide, and corticosteroid. The patient was treated with ceftriaxone and trimethoprim-sulfamethoxazole, together with drainage of the brain abscess. Regular brain MRI follow-ups showed that intracranial lesions were gradually absorbed and improved.

A case report of brain abscess caused by Nocardia farcinica

Background

Brain abscess due to the Nocardia genus is rarely reported and it is usually found in immunocompromised patients. Treatment of Nocardia brain abscess is troublesome and requires consideration of the severity of the underlying systemic disease. The difficulties in identifying the bacterium and the frequent delay in initiating adequate therapy often influence the prognosis of patients.

Case presentation

Here, we report a rare case of brain abscess caused by Nocardia farcinica. The patient’s medical history was complicated: he was hospitalized several times, but no pathogens were found. At last, bacteria were found in the culture of brain abscess puncture fluid; the colony was identified as Nocardia farcinica by mass spectrometry. Targeted antibiotic treatment was implemented, brain abscess tended to alleviate, but the patient eventually developed fungal pneumonia and died of acute respiratory distress syndrome (ARDS).

Conclusion

Brain abscess caused by Nocardia farcinica can appear in non-immunocompromised individuals. Early diagnosis, reasonable surgical intervention, and targeted antibiotic treatment are critical for Nocardia brain abscess treatment. In the treatment of Nocardia brain abscess, attention should paid be to the changes in patients’ immunity and infection with other pathogens, especially fungi, avoided.

Primary Nocardia brain abscesses and role of intraventricular antibiotic therapy

Intracranial infections caused by Nocardia Farcinica are challenging to treat and potentially lethal because of the organism's tendency to resist antibiotics and high relapse rates. Such infections usually occur in immunocompromised patients who have predisposing factors. Nocardia brain abscesses carry a higher morbidity and mortality rate than other bacterial brain abscesses, with reported mortality rates of 55% (even up to 90% in cases of late diagnosis) in immunocompromised patients. An aggressive therapeutic approach is required and an early identification of the microorganism is paramount. Given the high microbial resistance, it is usually an infection with a low cure rate. We present the case of a patient with primary brain abscesses due to Nocardia Farcinica, successfully treated with intrathecal Amikacin administration through ventricular drain, in addition to surgical evacuation and intravenous antibiotic therapy. In this case, clinical and radiological improvement were observed once the intrathecal treatment was started. To our best knowledge, no cases of intraventricular use of Amikacin have been previously reported to treat this type of infection and we believe that it may be useful in properly selected patients.

Clinical Presentation, Management, and Outcomes of Patients With Brain Abscess due to Nocardia Species

Background

Nocardial brain abscesses are rare, and published literature describing brain abscesses due to Nocardia species is limited to individual case reports or small series. We report one of the largest contemporary retrospective studies describing risk factors, diagnostic evaluation, management, and outcomes of nocardial brain abscess.

Methods

Retrospective review of all adults with brain abscess due to culture-confirmed Nocardia species at our institution between January 1, 2009, and June 30, 2020.

Results

Overall, 24 patients had nocardial brain abscesses during the study period. The median age at presentation was 64 years, and 62.5% were immunocompromised. Pulmonary and cutaneous infections were the most common primary sites of nocardial infection. All 24 patients had magnetic resonance imaging performed, and the frontal lobe was the most commonly involved. The most common organism isolated was Nocardia farcinica, followed by Nocardia wallacei and Nocardia cyriacigeorgica. Thirteen patients were managed with antimicrobial therapy alone, while 11 had both medical and surgical management. In all patients, dual therapy was recommended for the initial 6 weeks of treatment, and 22 patients received at least 1 oral agent as part of their final antibiotic regimen, predominantly trimethoprim-sulfamethoxazole and linezolid. Fourteen patients achieved complete clinical and radiographic resolution of infection.

Conclusions

Nocardia is an important cause of brain abscess in the immunocompromised host. Early diagnostic and therapeutic aspiration may help health care providers confirm the diagnosis, choose an appropriate antimicrobial regimen, and achieve source control.

Nocardiosis in glomerular disease patients with immunosuppressive therapy

Background

Glomerular disease patients have a high risk of infection, which contributes to the progression of disease per se and mortality, especially in those with long-term use of glucocorticoids and (or) immunosuppressive agents. Cases of sporadic nocardiosis have been reported in glomerular disease patients, and this observation was conducted to comprehensively understand the manifestations of and treatments for nocardiosis, which is commonly misdiagnosed as pneumonia or tuberculosis or even as lung cancer or metastatic tumors in glomerular disease patients.

Methods

We reviewed the demographic characteristics, laboratory abnormalities, radiological features, and treatments of 7 patients with nocardiosis and glomerular disease receiving steroids and immunosuppression therapy at the nephrology department of the Second Xiangya Hospital between 2012 and 2019.

Results

It was found that all 7 patients had been receiving methylprednisolone for renal disease at a median dose of 20 mg per day and a median duration of 4 months before developing nocardiosis. There were 4 males and 3 females, and the median age was 52.14 years. All 7 patients had hypoalbuminemia at the time of admission. In addition, various cystic abscesses in the subcutaneous tissue, with or without lung and brain involvement, were observed in these patients. Encouragingly, body temperatures returned to normal, and subcutaneous abscesses diminished or disappeared with compound sulfamethoxazole treatment alone or in combination with linezolid, imipenem and mezlocillin/sulbactam.

Conclusions

It was shown that multisite abscesses, including subcutaneous, pulmonary and cerebral abscesses, were the common manifestations of nocardiosis in glomerular disease patients. Sulfonamide was the first-line antibiotic therapy for nocardiosis, and combinations of other antibiotics were also needed in some serious cases.

Asymptomatic cerebral abscesses after pleuropulmonary Nocardia farcinica infection

We report the case of a 68-year-old man with long-term receipt of steroid therapy who was diagnosed with cerebral abscesses and pulmonary nocardiosis. This patient displayed only respiratory symptoms. Confirmation of Nocardia farcinica species was achieved by specific PCR sequencing of the 16S ribosome RNA in bronchoalveolar lavage cultures. Cerebral magnetic resonance imaging revealed abscesses. Antibiotic therapy with trimethoprim/sulfamethoxazole was prescribed given the results of susceptibility tests and was maintained for 12 months, with no evidence of relapse afterwards.

Nocardia farcinica masquerading as intracerebral metastases in advanced metastatic prostatic cancer

A 67-year-old man with metastatic prostate cancer and underlying asymptomatic pancytopenia presented with a 1-week history of general malaise, left leg weakness and facial numbness. Initial brain imaging demonstrated two rim-enhancing lesions felt to represent intracerebral metastasis. Following neurosurgical referral, a multidisciplinary meeting decision was made for best supportive care and dexamethasone was given. He developed multiple cutaneous lesions, which on incision and drainage revealed Nocardia farcinica Repeat brain imaging showed enlargement of the existing cavitating lesions and appearance of new lesions, now typical of cerebral abscesses. A diagnosis of disseminated nocardiosis with cutaneous and intracerebral infection was reached. He started taking empirical treatment with intravenous meropenem, co-trimoxazole and subsequent addition of amikacin, with little improvement. On further review of sensitivities, moxifloxacin was added. Following over 1 month of antimicrobial treatment, his neurological symptoms, cutaneous lesions and repeat MRI of the brain had improved.

Intracranial peripherally enhancing lesions in cardiac transplant recipients: A rare case series and literature review

Intracranial peripherally enhancing lesions in immunosuppressed solid organ transplant recipients represent a unique diagnostic and management dilemma due to the vast array of differentials that demand consideration. Diagnosis of the underlying pathology is often guided by the use of magnetic resonance imaging (MRI). We present the first published case series of three cardiac transplant recipients with significantly atypical neuroradiological findings contrary to the tenets of contemporary literature. Our rare case series consists of: (1) A sterile Mycobacterium pyogenic abscess mimicking glioblastoma multiforme due to an immunosuppressed state (2) Epstein Barr Virus encephalitis masquerading as Central Nervous System Post-Transplant Lymphoproliferative Disorder (3) An unusual case of partially treated disseminated Nocardiosis warning of the need to consider the immunosuppressed state and partial treatment response obfuscating classical MRI appearances. We utilise these unprecedented cases as the basis of a literature review to understand the pathophysiology behind the peculiar imaging findings in this rarefied cohort of transplant recipients, and rationalise why the MRI findings in each instance contradicts the accepted imaging patterns. In the setting of potential unreliability of neuroradiology in this immunosuppressed unique subgroup, we hope to impart to clinicians that definitive diagnosis obtained by emergent neurosurgical intervention may be necessary to accurately and expediently guide further medical management.

Nocardia paucivorans cerebellar abscess: Surgical and pharmacotherapy

Background

Nocardia species are ubiquitous in nature and mainly cause pulmonary disease in humans; however, they can also infect the central nervous system and skin. The management of cerebellar nocardiosis is troublesome and requires multiple considerations of the severity of the underlying systemic disease, difficulties in identifying the bacterium, and frequent delay in initiating adequate therapy.

Case Description

We report a 52-year-old diabetic female patient with Nocardia paucivorans cerebellar abscesses. Brain magnetic resonance imaging (MRI) revealed innumerable small ring-enhancing lesions of posterior fossa. In this report, we present a case of primary single cerebellar abscesses due to N. paucivorans. Early diagnosis and surgical interventions were significant for the patient. The diagnosis was confirmed by DNA sequencing and the organism was susceptible to trimethoprim-sulfamethoxazole (TMP/SMX). The patient was successfully treated with drugs and surgical excision.

Conclusion

According to the literature, surgical excision or aspiration of cerebellar abscess seems to provide favorable outcomes. In our experience, a successful outcome was achieved with subtotal resection and prolonged adequate antibiotic therapy.

Neurosurgical management of multiple intracranial Nocardia and Enterococcus abscesses in an immunocompetent patient

Nocardia farcinica and Enterococcus faecium are both rare causes of cerebral abscess. The former is associated with high morbidity and mortality. We describe a neurosurgical approach to the management of multiple intracranial abscesses of dual microbial pathology in an immunocompetent patient to achieve a good outcome.