Anthracosis - Breathing in Black

Introduction

Asymptomatic anthracosis shows pigment accumulation without a cellular reaction. This deposition is seen in the connective tissue, along with the lymph nodes, or lymphoid tissue in the bronchi or lung hilus. Anthracosis is a chronic condition that presents with dyspnea that is difficulty in breathing, and cough in non-smokers.

What Is Anthracosis?

Anthracosis is black discoloration of the bronchial mucosa of the lung. This leads to the occlusion and narrowing of the bronchial lumen. Anthracosis is a chronic condition that presents with dyspnea and cough in non-smokers. Also, exposure to dust and smoke causes anthracosis. Pulmonary function tests help detect an obstructive pattern. The disease does not improve with a group of drugs called bronchodilators. Computed tomography (CT scan) helps diagnose lymph nodes or bronchial calcification and lesions. The final diagnosis calls for bronchoscopy. Culture samples for tuberculosis can help. Endobronchial ultrasound detects nodular patterns in surrounding lymph nodes.

Anthracosis is a condition due to coal or carbon inhalants. Anthracosis is the asymptomatic and mild version of pneumoconiosis. This is caused by the accumulation of carbon in the lungs by constant exposure to pollution, smoke, or coal dust. Anthracosis presents as superficial black discoloration or scattered black spots. Anthracosis shows distortion and narrowing of the bronchial lumen.

Etiologic Factors Associated With Anthracosis

The exact etiology is unknown, unclear, and yet to be discovered. The following factors are said to cause anthracosis:

• Dust: Exposure to coal dust in the workplace, with the deposition of mica and silica. Crystals are noticed in the lymph nodes. Some show aluminum silicate and quartz deposits. Silicon and aluminum deposits are higher in farmers as compared to other occupations.

• Smoke: Smoke from biomass is the smoke produced due to the burning of wood and manure for cooking. This is a significant risk factor. Smoke can induce chronic respiratory diseases. Cigarette smoking is not associated with Anthracosis.

• Bronchogenic Carcinoma: Lung cancer cases show a high level of iron, calcium, copper, and lead deposits. However, cancer has low deposits of silicon and aluminum. No clear association can be noticed.

• Tuberculosis: The presence of tuberculosis increases the risk of the development of anthracosis.

What Is the Pathology of Anthracosis?

Anthracosis begins in the bronchioles. The bronchial wall and lymph nodes show carbon deposition. Bronchitis also indicates the presence of fibrosis. Other organs like the liver, spleen, and esophagus might show involvement.

What Are the Clinical Features of Anthracosis?

Anthracosis presents with symptoms like chronic obstructive pulmonary disease without a history of smoking, though. The following are the features of Anthracosis:

• Cough.

• Dyspnea means difficulty breathing.

• Unexplained weight loss.

• Fever.

• Wheezing.

• Decreased breath sounds.

• Enlarged lymph nodes.

• Vocal cord paralysis.

How To Diagnose Anthracosis?

Anthracosis presents itself as chronic obstructive pulmonary disease. A diagnostic test to detect anthracosis is as follows:

• X Rays: X-Ray imaging shows non-homogeneous infiltration and lesion in the lungs.

• Computed Tomography Scan: CT scan shows lymphadenopathy, calcifications, bronchial narrowing and stenosis, necrotic lymph nodes, and opacities.

• Magnetic Resonance Imaging: MRI scan shows low-density images as compared to cancer imaging.

• Bronchoscopy: Bronchoscopy is the gold standard for diagnosing anthracosis. It shows black lesions, narrowing of bronchioles, bronchial swelling, erythema, or redness. Generally, the lesion involves the right middle lobe of the lung, and the involvement can be unilateral or bilateral, or it can be localized or generalized. It is difficult to obtain a biopsy due to hard consistency and bleeding during the procedure.

• Ultrasound: Ultrasound detects scattered hyperechoic nodular patterns.

• Spirometry: These are the pulmonary function tests that show obstructive lung disease or calcifications.

How To Treat Anthracosis?

No treatment line is established for Anthracosis. However, the following measures may help:

• Bronchodilators: Bronchodilators are drugs that help dilate bronchioles. Long or short-acting bronchodilators can be used.

• Corticosteroids: Corticosteroids are drugs that reduce inflammatory responses. They can be used as inhalants or systemic medications.

• Anti-Tubercular Drugs: The use of anti-tuberculosis drugs can improve symptoms as well as radiographic findings.

• Surgical Management: Surgical placement of bronchial stents is done in severe cases.

What Is the Scientific Evidence Regarding Anthracosis?

Anthracosis is the black pigment discoloration of bronchi causing bronchial destruction and deformity. Anthracosis is an ancient condition reported in mummies. This condition was seen in pneumoconiosis patients. Most authors considered this disease as a complication of occupational diseases.

• Chung et al., Towhidi et al., and Aslani et al. reported arthrofibrosis in three percent, eight percent, and ten percent of routine bronchoscopies. Also, anthracosis in 21 percent of routine bronchoscopies was found. Anthracofibrosis distorts the bronchial lumen. Along with the lung, anthracosis involves lymphoreticular organs and the liver. To determine the origin of anthracosis, Tanaka et al. performed a particular bronchoscopic study in small bronchi and found that peripheral airways are the initial site of anthracosis granule formation.

• Many patients with anthracosis are not exposed to dust at work. Muliez et al. showed patients with anthracosis have mica in lung biopsy. This indicates that anthracosis plaque is associated with pollution. Kato and Kawaga studied the effect of polluted air on the pathogenesis of chronic respiratory disease and anthracosis. The findings show the impact of roadside air on the respiratory tissue is not as severe.

• Wang and coworkers examined surgically resected tissues of pulmonary adenocarcinoma and concluded that adenocarcinoma heavily anthracitic lungs could progress to advanced stage or adenocarcinoma with poor prognosis.

• Chung et al. found infective etiology for severe anthracosis.

What Is the Clinical Course, Quality of Life, and Follow-Up of Anthracosis?

Follow-up of radiographic mass lesions shows a slow progression of the lesion, which is different from the spread pattern of malignant lesions. Therefore, such cases should be followed up with a lung biopsy. Patients who suffered only from Anthracosis or a combination with malignancy had lower survival rates than patients with tuberculosis.

Conclusion

Anthracosis presents just like any other obstructive pulmonary disease. Smoking and tuberculosis were not found to be more common in Anthracosis and anthracofibrosis lung disease. However, dust exposure, bio-smoke, and malignancy relate to Anthracosis. The condition is very much treatable with conservative management. Diagnosis is possible with various imaging tests.