High-resolution CT findings of patients with pulmonary nocardiosis

A Case of Asymptomatic Pulmonary Nocardia cyriacigeorgica Infection With Mild Diabetes Mellitus

Nocardiosis is a relatively rare opportunistic infection, ranging from localized to systemic diseases, commonly occurring in immunocompromised patients with high mortality rates. We present a case of a 61-year-old man who received medical treatment for type 2 diabetes mellitus and underwent a physical examination that showed abnormal chest shadows on radiography. Chest computed tomography revealed bronchiectasis and infiltration in the left lower lobe. Nocardia spp. was detected in the bronchial washes, and he was started on sulfamethoxazole-trimethoprim under the diagnosis of pulmonary nocardiosis. 16S ribosomal RNA gene sequencing analysis identified the species as Nocardia cyriacigeorgica. His pulmonary lesions successfully improved after treatment for six months. Pulmonary nocardiosis often presents with symptoms such as hemoptysis and blood-tinged sputum, and bronchiectasis has been identified as an underlying condition. Even in hosts without underlying immunocompromising conditions, Nocardia spp. can be a causative microorganism of pulmonary infections, and it should be considered in the differential diagnoses.

Localized Pulmonary Nocardia farcinica Infection As the Presenting Symptom of Acquired Immunodeficiency Syndrome

Nocardiosis is an opportunistic infection that most commonly affects immunocompromised patients, with clinical presentations ranging from localized to disseminated disease. In the United States, the reported incidence is approximately 500 to 1,000 cases per year, with an observed male-to-female predominance of 3:1. We present the case of a 37-year-old male with a past medical history of malaria who presented with watery, non-bloody diarrhea for four days associated with a fever for two weeks. The human immunodeficiency virus (HIV) was positive in the emergency room before admission. Computerized tomography (CT) of the chest with contrast revealed an irregular pleural base mass in the right lower lobe with several small air foci. CT of the abdomen and pelvis revealed the right pleural base lung mass to be adherent to the diaphragm, as well as mild splenomegaly. The cluster of differentiation 4 (CD4) count was 9 cells/mm³. An acid-fast bacilli (AFB) sputum culture was positive for Nocardia farcinica. Trimethoprim-sulfamethoxazole was started for a Nocardia farcinica pulmonary infection, in addition to antiretroviral therapy. The patient was strongly encouraged to follow-up at the outpatient department.

Nocardiosis with diffuse involvement of the pleura: A case report

BACKGROUND

Nocardiosis is an uncommon infection that usually occurs in immunocompromised patients, and the pulmonary system is the most common site. We report an uncommon case of nocardiosis with diffuse involvement of the pleura, which presented as multiple localized nodular or hillock lesions on computed tomography (CT) with local chest wall infiltration.

CASE SUMMARY

A 54-year-old woman was referred to our hospital due to cough and fever for 20 d. She had a history of nephrotic syndrome for 7 mo and was given prednisone (60 mg/d) 6 mo previously. The hormone was then gradually reduced to the current dose of 25 mg/d. Chest CT showed many nodular or hillock lesions in the right pleura, mediastinum, and interlobar fissure areas. On the lower layer, one lesion infiltrated the chest wall. She was treated with piperacillin sodium and sulbactam sodium, but the therapeutic effect was not good. In this regard, ultrasound-guided local infiltration anesthesia was further conducted for perihepatic hydrops drainage to improve diagnostic accuracy. Puncture fluid culture isolated Nocardia species, confirming the diagnosis of nocardiosis. Subtype Nocardia farcinica was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antibiotic treatment was switched to trimethoprim/sulfamethoxazole and imipenem. After 8 d of treatment, the patient was discharged from the hospital with improved condition, and she has been recurrence-free for 2 years.

CONCLUSION

This report illustrates that nocardiosis should be suspected when clinicians encounter patients who are immunocompromised and have diffuse involvement of the pleura.

Pulmonary nocardiosis caused by Nocardia exalbida mimicking lung cancer

Nocardiosis is an uncommon infection caused by Nocardia species, but it can often occur in immunocompromised patients. As computed tomography (CT) findings of pulmonary nocardiosis, consolidation, masses, and nodules are often found, but lymph node enlargement is infrequent. Nocardia exalbida was first isolated in 2006, and there are still few reports on this microorganism. We report a case of pulmonary nocardiosis caused by N. exalbida presenting as a mass and lymph node enlargement that mimicked lung cancer. A 76-year-old man was referred and admitted to our hospital because of persistent cough, sputum production, and chest discomfort. Chest CT showed a mass in the superior segment of the left upper lobe and mediastinal lymph node enlargement. After we performed bronchoscopies, Nocardia species was isolated in a cultured specimen and identified as N. exalbida. This case required differentiation from lung cancer and was difficult to diagnose.

Pulmonary nocardiosis mimicking small cell lung cancer in ectopic ACTH syndrome associated with transformation of olfactory neuroblastoma: a case report

Background

Pulmonary nocardiosis frequently develops as an opportunistic infection in cell-mediated immunosuppressive patients, and sometimes requires differentiation from pulmonary malignancy. Ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is a neoplastic disorder which leads to impaired cell-mediated immunity, and is commonly associated with small cell lung cancer (SCLC). Because pulmonary infection and causative malignancy can appear as pulmonary lesions with EAS, differentiation of these diseases remains a critical issue for physicians.

Case presentation

A 52-year-old woman with progressive lower limb paralysis and general fatigue was referred to us. She had been diagnosed with olfactory neuroblastoma (ONB) and treated with surgery and radiation therapy 10 years before the referral and had required stereotactic radiosurgery and chemotherapy 4 years later for a relapse of the ONB. On referral, she presented with Cushing’s syndrome with elevated cortisol and ACTH levels. Potassium supplement improved her symptoms; however, a month later, she was urgently hospitalized due to acute pleuritic chest pain on inspiration. Chest computed tomography revealed left lower lobular consolidations and a contralateral nodule in the right middle lobe. The clinical history and laboratory work-up suggested that her Cushing’s syndrome had most likely arisen from EAS. Additionally, the lungs were suspected as the ACTH source due to high levels of progastrin-releasing peptide and progressive pulmonary consolidation with a contralateral nodule, suggesting SCLC. However, histological examination from bronchoscopy revealed no evidence of malignancy, and Nocardia cyriacigeorgica was isolated from bronchoalveolar lavage fluid. Sulfamethoxazole/trimethoprim improved her pulmonary lesions. Somatostatin receptor scintigraphy revealed strong tracer uptake in the ONB lesions, indicating that the origin of the EAS was the olfactory tumor. However, histological examination of ONB specimens resected 10 years earlier showed no intracytoplasmic immunopositivity for ACTH.

Conclusions

We highlight a rare case of pulmonary nocardiosis, which was associated with EAS mimicking SCLC, and was related to ONB transformation. Nocardiosis has to be considered even though anamnestic, clinical, and radiological aspects suggest the presence of metastasis. Additionally, physicians should carefully monitor patients with ONB for the development of Cushing’s symptoms because the tumor can transform into an ACTH-producing form, even after long-term follow-up.

CT findings of pulmonary nocardiosis: a report of 9 cases

Background

Pulmonary nocardiosis often occurs among immunocompromised patients, especially in those with impaired cell immunity related to AIDS and transplant. As the number of patients receiving transplant, the occurrence of pulmonary nocardiosis may also increase. Radiologic characteristics of this entity have not been well documented. In present study, CT findings of clinical confirmed pulmonary nocardiosis were retrospectively reviewed in order to understand CT features of pulmonary nocardiosis.

Methods

Electronic databases of Shenzhen People's Hospital, Shenzhen, China, and the Third People's Hospital of Longgang District, Shenzhen, China were searched for patients with definitive diagnosis of pulmonary nocardiosis and available CT images. Nine patients were founded and they were included in this retrospective analysis. Clinical presentations at diagnosis and related medical history were recorded. CT images were retrospectively reviewed by two radiologists in consensus.

Results

The patients consisted of seven men and two women with a median age of 47 years (range, 20-73 years). There were three immunocompromised patients and six immunocompetent patients. The latter included two patients had history of bronchiectasis. The symptoms at the diagnosis were nonspecific of fever, cough, sputum, dyspnea, chest pain, and hemoptysis. CT findings included: lung consolidation (n=8) with cavitation in three cases and foci of decreased enhancement in one patient who had contrast-enhanced CT, nodules/masses (n=6) with cavitation in two patients, ground-glass opacity (n=4), centrilobular nodules (n=4), pleural effusion (n=4), bronchiectasis (n=4), interlobular septal thickening (n=3), interlobular reticular opacity (n=3), lymph node enlargement (n=2), halo sign (n=2) and mucoid impaction (n=1).

Conclusions

Lung consolidation and nodules/masses are the most common findings, but CT findings of pulmonary nocardiosis are diverse and nonspecific. In some clinical background, such as immunocompromised patients or with some underlying lung diseases, consolidation or nodules/masses with cavitation may suggest the possibility of pulmonary nocardiosis.

Pulmonary Nocardiosis: A Clinical Analysis of 30 Cases

Objective Pulmonary nocardiosis frequently develops as an opportunistic infection in patients with malignant tumor and is treated with steroids. This study was performed to clarify the clinical features of pulmonary nocardiosis in Japan. Methods The patients definitively diagnosed with pulmonary nocardiosis at our hospital between January 1995 and December 2015 were retrospectively investigated. Results Nineteen men and 11 women (30 in total) were diagnosed with pulmonary nocardiosis. Almost all patients were complicated by a non-pulmonary underlying disease, such as malignant tumor or collagen vascular disease, or pulmonary disease, such as chronic obstructive pulmonary disease or interstitial pneumonia, and 13 patients (43.3%) were treated with steroids or immunosuppressors. Gram staining was performed in 29 patients, and a characteristic Gram-positive rod was detected in 28 patients (96.6%). Thirty-one strains of Nocardia were isolated and identified. Seven strains of Nocardia farcinica were isolated as the most frequent species, followed by Nocardia nova isolated from 6 patients. Seventeen patients died, giving a crude morality rate of 56.7% and a 1-year survival rate of 55.4%. The 1-year survival rates in the groups with and without immunosuppressant agents were 41.7% and 59.7%, respectively, showing that the outcome of those receiving immunosuppressants tended to be poorer than those not receiving them. Conclusion Pulmonary nocardiosis developed as an opportunistic infection in most cases. The outcome was relatively poor, with a 1-year survival rate of 55.4%, and it was particularly poor in patients treated with immunosuppressant agents. Pulmonary nocardiosis should always be considered in patients presenting with an opportunistic respiratory infection, and an early diagnosis requires sample collection and Gram staining.

An Unusual Presentation of Nocardiosis in an Allogeneic Transplant Recipient

Nocardiosis is a rare cause of opportunistic infection post hematopoietic stem cell transplant (HSCT) occurring in about 0.3% of patients. The risk factors include delayed immune reconstitution, prolonged neutropenia, and graft-versus-host disease. The most common site of infection is the lung, followed by the brain and the skin. Concomitant pulmonary and central nervous system (CNS) nocardiosis is an extremely rare entity as presented in our case. We present the case of a 72-year-old male at 137 days post transplant presenting with complaints of headache and slurred speech. A magnetic resonance imaging (MRI) brain scan revealed two ring-enhancing lesions: 1.6 cm in the right frontal lobe and 1 cm in the left parietal lobe. The patient had an outpatient computed tomography (CT) chest scan a month prior showing a 1.4 cm solid right upper lobe nodule prompting bronchoalveolar lavage (BAL) that was nondiagnostic. On repeat inpatient CT chest scan, the nodule had increased in size to 3.3 x 2.5 x 2.1 cm, prompting a percutaneous fine-needle aspiration biopsy. He was started on empiric trimethoprim-sulfamethoxazole (TMP-SMX) and liposomal amphotericin B. The tissue mycology and acid-fast cultures were reported positive for nocardia species. The patient was discharged on intravenous TMP-SMX. A follow-up CT chest scan and MRI brain scan four months later showed resolution of the right upper lobe nodule and significant decrease in size of the brain lesions. The patient will continue TMP-SMX for a total of nine to 12 months. Given the increase in transplant recipients and the ongoing risk of developing nocardiosis several months post transplant, there is a need for standardized diagnostic and treatment guidelines. Meanwhile, our case highlights the importance of aggressiveness in pursuing a prompt diagnosis including invasive procedures, if required, in order to begin specific treatment.

Impact of pre-transplant pulmonary infection developed in horizontal laminar flow unit on the outcome of subsequent allogeneic hematopoietic stem cell transplantation

BACKGROUND

So far, there is very little literature on how pre-transplant pulmonary infection developed in horizontal laminar flow unit (HLFU) affects outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODS

A retrospective analysis was performed on allo-HSCT recipients who were diagnosed with pre-transplant pulmonary infection developed in HLFU between January 2012 and December 2012. Various tests were analyzed to evaluate the overall survival (OS) and pulmonary infection rate after allo-HSCT.

RESULTS

Among 317 patients who received allo-HSCT from related donors, 7 cases of human leukocyte antigen (HLA)-haploidentical transplantation reported a fever, cough, and other symptoms before transplantation. Chest radiography findings showed pulmonary infection, and the C-reactive protein (CRP) level was higher than normal, which confirmed pulmonary infection (incidence rate 2.21%). The Breslow test suggested that the early survival rate was lower in the group with pre-transplant pulmonary infection than in the group without pre-transplant pulmonary infection (OS: 28.4 vs. 42.4 months; P=0.023); the early survival rate was lower in patients with a pulmonary infection accompanied by bilateral pleural effusion than in patients without pleural effusion (OS: 1.5 vs. 36.3 months; P=0.010). In the first month after transplantation, the difference in the CD4CD45RO+CD45RA- and CD4CD45RO-CD45RA+ between the groups with and without pre-transplant pulmonary infection was statistically significant (P<0.05). Patients with pre-transplant pulmonary infection who survived >3 years had a higher rate of pulmonary infection in the first 2 months after allo-HSCT than those without pre-transplant pulmonary infection [100% (5/5 patients) vs. 38.1% (118/310); χ(2)=5.542, P=0.019].

CONCLUSIONS

Development of pre-transplant pulmonary infection in the HLFU in patients with hematological malignancies who receive HLA-haploidentical HSCT is associated with an increased risk of recurrent pulmonary infection in the early period after transplantation; however, there is no impact on patients' long-term survival rate.

Pulmonary melanoma and "crazy paving" patterns in chest images: a case report and literature review

Background

In the lung, melanoma is mostly arranged as patterns of multiple nodules, solitary nodules, or miliary invasions. Very rarely, it also displays a “crazy paving” pattern (also described as a “paving stone,” “flagstone,” or “slabstone” pattern), which is rarer still in discrete bilateral nodules. This pattern is considered to be caused by pulmonary alveolar proteinosis, but its association with various diseases is unclear.

Case presentation

A 60-year-old man was diagnosed with pulmonary melanoma. Computed tomography revealed discrete bilateral nodules surrounded by a “paving” pattern. A literature review found more than 40 types of diseases that have presented with “paving” patterns in the lung—predominantly pulmonary alveolar proteinosis, viral pneumonia, exogenous lipoid pneumonia, bacterial pneumonia, pulmonary alveolar microlithiasis, interstitial pneumonia, ARDS, squalene aspiration pneumonia, radiation pneumonitis, drug-induced pneumonitis, pulmonary leptospirosis, pulmonary hemorrhage, and pulmonary nocardiosis.

Conclusions

We describe the first case of pulmonary melanoma in the form of discrete bilateral nodules accompanied with a computed tomography paving pattern. Although pulmonary paving patterns are rare, more than 40 diseases reportedly display them; clinicians should consider melanoma of the lung in differential diagnoses for patients who show such a pattern.

Pulmonary nocardiosis in Chronic Obstructive Pulmonary Disease: A new clinical challenge

Pulmonary nocardiosis (PN) is a rare but severe disease caused by Nocardia spp. Despite the traditional description as opportunistic infection, case reports and case series of pulmonary nocardiosis have recently been reported in immunocompetent patients too, in particular among people with chronic pulmonary diseases such as advanced Chronic Obstructive Pulmonary Disease (COPD). PN is characterized by non-specific symptoms and radiological findings; bacteriological culture can be difficult. For the reasons above, diagnosis of PN is challenging, sometimes resulting in a misdiagnosis of tuberculosis. We report an interesting case of PN in a 75-year-old male with COPD. He complained a 3-months history of fatigue, evening rise in body temperature, night sweats, unexplained weight loss of 5 kg, worsening dyspnea, cough and mucopurulent sputum. The chest X-ray showed multiple nodules with cavitations bilaterally in the apical and subclavian regions. Nocardia cyriacigeorgica with 100% identity was identified in three sputum samples. Since the patient has never undergone a systemic and/or inhaled steroid therapy, and has no respiratory failure and comorbidities entailing immunodepression, it is conceivable that, in this immunocompetent patient, the COPD could represent an isolated risk factor for PN. Risk factors, clinical presentations, radiographic findings, differential diagnosis and review of the literature of PN cases in COPD, pointing out the similarities and differences, are also described.

Pulmonary nocardiosis revisited: A case series

Pulmonary nocardiosis is a rising bacterial infection, with a high propensity for misdiagnosis. On account of a paucity of prospective studies, there is limited understanding on various aspects of its diagnosis and treatment. We present three patients with pulmonary nocardiosis, with emphasis on the predisposing factors, variable disease course, and treatment issues. There is a need to understand the basis of these discrepancies so as to rationalize the management of this potentially fatal infection.

Computed tomography features of pulmonary nocardiosis in immunocompromised and immunocompetent patients

BACKGROUND

Nocardiosis primarily occurs in the setting of immunocompromising conditions. However, it may also occur in immunocompetent patients. We described computed tomography features of pulmonary nocardiosis and compared immunocompetent and immunocompromised patients.

MATERIAL/METHODS

CT images of 25 patients (Mean age of 39.5 years; 76% male) with pulmonary nocardiosis proved by bronchoalveolar lavage or biopsy were reviewed by two experienced pulmonary radiologists and detailed findings were reported on. Fourteen patients (56%) were immunocompetent, while 44% had an underlying immunocompromising condition, including chronic granulomatous disease (CGD) (n=4), diabetes mellitus (DM) (n=2), malignancy (n=2), HIV (n=1), concomitant CGD and DM (n=1), and steroid therapy for nephrotic syndrome (n=1).

RESULTS

Most patients had bilateral involvement with no zonal predominance. Multiple pulmonary nodules (96%) were the most common CT findings, followed by consolidation (76%) and cavity (52%). Other findings included bronchiectasis (48%), pleural thickening (40%), ground glass opacity (32%), mass-like consolidation (20%), intrathoracic lymphadenopathy (16%), pleural effusion (12%), reticular infiltration (4%), and pericardial effusion (4%). There was no statistically significant difference in the CT findings of immunocompromised and immunocompetent groups.

CONCLUSIONS

Pulmonary nocardiosis presents mainly as multiple pulmonary nodules, consolidations, and cavity in both immunocompromised and immunocompetent patients. However, these features are more suggestive of nocardiosis in the setting of an underling immunocompromised condition.