A Rare Case of Pulmonary Actinomycosis Presented With Hollow Mass Lesion and Elevated CEA Level

Chiang MC

Published on: 2022-06-09

Abstract

Pulmonary actinomycosis is a rare infectious disease led by Actinomycosis israelii, with non-specific clinical and image presentation which is easily misdiagnosed with pneumonia or malignancy. It is more common in patients with poor oral hygiene and underlying respiratory disease. Serum CEA level is taken as a predictive factor of prognosis in lung cancer. However elevated serum CEA level is not always associated with malignancy. Aging, type 2 diabetes mellitus, infection, inflammation, and cigarette consumption can lead to increasement of serum CEA level. Here we report a case of pulmonary actinomycosis complicated with lung mass and elevated serum CRP level. Chest image series showing the remission of the lung mass after antibiotic treatment are contained in this report. Gradually decreased serum CEA level throughout the clinical course is also record and related studies about this phenomenon will be discussed either.

Keywords

Pulmonary Infection; Thoracic Actinomycosis; Bacteriology; Serum CEA

Introduction

Actinomyces infection is caused by Actinomyces species, mostly Actinomycosis israelii [1].Cervicofacial, thoracic, abdominal, pelvis, skin, brain and other organs have been reported to be involved, while pulmonary actinocmycosis accounts for 15% and male is three times more than female[2,3]. Individuals with poor oral hygiene, preexisting respiratory disease such as asthma, chronic bronchitis, bronchiectasis, and alcoholism, long term smoker, are more vulnerable to respiratory tract actinomyces infection [4]. Clinical presentation and image findings of pulmonary actinomycosis may be similar to benign disease or malignancy, which is usually confusing for physicians. Reliable diagnosis relies on sulfur granules and gram-positive, beaded filamentous bacilli in histologic report [5]. Elevated serum Carcinoembryonic Antigen (CEA) level is widely associated with several malignancy such as colorectal, lung, pancreatic adenocarcinoma [6-8]. Here we report a case who was found to have a lung mass with elevated serum CEA level, turning out to be diagnosed with pulmonary actinomycosis. Chest image series and lab data change of the nine-month long treatment course are also presented comprehensively.

Case Presentation

A 78 years-old woman was sent to our hospital due to persistent dyspnea, produc-tive cough, and progressing hemoptysis. She was a housewife and with underlying disease of hypertension. She denied alcohol or cigarette consumption and any known allergies. Vital sign measured in emergency room was as below: blood pressure 113/73 mmHg, body temperature 37.8°C, cardiac frequency 121 ppm, respiratory frequency 30, and oxygen saturation 91% with oxygen at 3 L/min by nasal cannula. Chest auscultation showed bilateral clear breathing sound without basal crackles or wheezing. Clinically significant laboratory findings included elevated white blood cell count (WBC) 17300 /μL, C-reactive protein (CRP) 69.47 mg/L and serum CEA level 10.29 ng/m. Blood sugar was 215 and HbA1C level was 9.5%, thus type 2 diabetes mellitus was occasionally diagnosed. Posterior – anterior chest X – ray revealed a mass lesion measured as 4 cm on the left upper lobe with cavity [Figure 1]. And COVID-19 exam showed negative outcome.

Figure 1: Chest X-ray on admission showed.

As the image findings was ambiguous and her clinical presentations were common in both pulmonary infectious disease and lung cancer, Levofloxacin and hemostasis agent were prescribed first, CT guided biopsy was then arranged for further survey. However, the effect of Levofloxacin was far from satisfying as symptoms persisted. Sputum culture, tuberculosis culture and smear showed negative finding. Finally, the pathology report of biopsy showed acute and chronic inflammation without malignancy, also Sulfur granules of Actinomyces was seen. [Figure 2]

Figure 2: The biopsy showed sulfur granules of Actinomyces. (Black arrow) (hematoxylin and eosin stain, 200X).

Since pulmonary actinomycosis was diagnosed, Ampicillin and Sulbactam treatment was started. Dramatic improvement was seen as the patient’s symptoms relieved a lot and no more hemoptysis was noted after 2 weeks of the treatment. As the symptoms subsided and the patient can maintain good saturation under room air, she was discharged from our ward with oral form Ampicillin, and we would follow up her condition in our patient department. A series of chest X ray was taken in the entire medical course showing the mass lesion became a little scaring lesion [Figure 3]. Decline of serum CEA level from 10.29 to 4.67 ng/mL is clearly demonstrated after 3 months of oral antibiotic treatment [Table 1]. Positron emission tomography scan was done 4 months after discharge and the outcome demonstrated no evidence of malignancy [Figure 4]. Besides, she stated no more hemoptysis, fever nor dyspnea were noted after discharge.

Figure 3: The serious chest radiography revealed the remission of the mass lesion. (A) Shows a mass lesion with cavity over left upper lobe. (B, C, D, E) showed gradual remission of the lesion under the antibiotic treatment. (F) Shows no obvious lesion.

Table 1: Serum CEA level in the nine-months long medical course.

Significant decrease of serum CEA level from 10.29 to 4.67 throughout the treatment course.

Figure 4: PET scan (A) Fibrotic tissue over left upper lung field. (B) An infiltrative lesion, inflammation process related. (C) Mediastinal lymph node lesions, might be reactive lymphadenopathy. (D) Soft tissue surrounding the left hip prosthesis.

Discussion

This case is a woman with an infection disease, pulmonary actinomycosis, complicated with elevated serum CEA level and cured by antibiotic treatment only. Serum CEA level decreased to less than 5 ng/mL without antineoplastic agent. Pulmonary actinomycosis has no specific clinical radiographic presentation which can be similar to several pulmonary diseases from infection to malignancy, image findings with cavities, lung nodules, peripheral consolidations, and pleural effusion have also been report. Its diagnosis relied on pathology finding of Sulfur granules in purulent tissue, combined with the clinical and radiological features. Cough, sputum, and chest pain are found to be the most seen clinical symptoms of it. Treatment of pulmonary actinomycosis required high dose intravenous beta-lactam antibiotic for several weeks followed by 6–12 months of oral treatment [9,10]. Duration of the symptoms before final diagnosis may be taken as a prognostic factor. Patients with longer duration of symptoms were prone to have refractory response to the antibiotic treatment [11]. Surgery indication included life threatening hemoptysis, poor response to the antibiotic treatment, and formation of fistula or empyema [9]. This case had well response to the antibiotic and no evidence of recurrence was noted. Obviously, antibiotic treatment alone works efficiently. CEA is a member of cell surface glycoprotein which is produced during fetal development and stops before the birth [12]. Serum CEA level is taken as a prognostic and predictive information of risk of recurrence and of death in non-small cell lung cancer (NSCLC) [13]. Patients of NSCLC with elevated serum CEA level tended to develop brain metastasis and carried a wore prognosis outcome [14,15]. Besides, elevated preoperative serum CEA level in NSCLC had significant lower 5-yers survival rate [16]. This case was presented with lung mass, dyspnea, hemoptysis and elevated serum CEA, as a result malignancy survey was an indispensable process. CEA has mainly three biological functions: cell adhesion, regular of signal transduction and innate immunity. In colon, an organ carries highest load of microorganism, CEA may serve as a defensive system able to trap and bind to the microorganism to prevent it from invading the epithelium [17]. Latest research supported the role of CEA in innate immunity, indicating that CEA contained a number of multi-antennary carbohydrate chains, capable to bind to bacteria in colon. The author assumed that the same protective mechanism may exist in upper alimentary tract or urinary bladder [18]. We suppose this mechanism also appeared in respiratory tract since trachea, bronchi and alveoli of lung are deviated from endoderm as alimentary tract is. The invasion of microorganism in respiratory tract may trigger the produce of CEA and lead to elevation in serum CEA level. Though this hypothesis has not been proved yet, significant elevated serum CEA level had been found in patient with pneumonia no matter the infectious source was pneumococcal, gram negative bacteria or chlamydial pneumonia [19]. A cross sectional study recruiting 18,131 non-smokers had performed a multivariate analysis between serum CEA level and variable factors such as WBC count, age, gender, etc. It revealed a positive relationship between WBC level and log-transformed serum CEA level indicating that the serum CEA level was affected by inflammation and infection to some degree [20]. Nonetheless, lower serum CEA level seems not to be a necessary outcome of cure of the infection. Stockley et al. record serum CEA level before and after the treatment in different respiratory tract disease. Antibiotic treatment in 9 patients of bronchiectasis had no significant difference while steroid treatment in 9 patients of bronchiolitis reduced serum CEA level significantly [21]. As mentioned before, serum CEA level can be affected by many physiological factors, personal history, or underlying disease. The elder group, even without specific underlying disease, has higher serum CEA level compared with younger subjects [22]. In addition, positive relationship between serum CEA level and HbA1C level or hyperglycemia has been confirmed [23, 24]. In this case, serum CEA level drop back to reference range from 10.29 to 4.66 as the infection disease was controlled by antibiotic successfully. However, the extent of decrease in serum CEA level may be limited as it might be affected by the age and type 2 diabetes.

Limitation and Perspective

The image of pathological biopsy was not a ‘typical’ pulmonary actinomycosis since no obvious sulfur granules or beaded filamentous bacilli was found. However, the symptoms improved, and the lung mass subsided after the antibiotic treatment. A single case may not illustrate the relationship between pulmonary infection and serum CEA level, and we need more study of the immune function of CEA in respiratory tract. The commonly used cut-off value of serum CEA is 5 ng/mL but many factors are known to affect its baseline level, we are hopeful that future research will provide more detailed survey on adjust of the cut-off value depending on different condition of each patient, making serum CEA level a more sensitive and accurate index of infection severity or a prognostic factor.

Conclusion

When confronting with a lung mass with elevated CEA level, we should keep diverse differential diagnosis in our mind besides malignancy. Infection disease, hemangiomas, pulmonary arteriovenous malformations can present as a lung mass on image study. Male and individuals with respiratory tract disease or poor oral hygiene are more vulnerable to pulmonary actinomycosis but this case is a woman without specific respiratory problems, reminding physicians that exceptional cases are always existing.

International Journal of Case Reports and Clinical Images