Occurrence of Bronchial Anthracofibrosis in Respiratory Symptomatics with Exposure to Biomass Fuel Smoke

Abstract

Introduction: Bronchial anthracofibrosis (BAF), confirmed bronchoscopically, is characterised by bluish-black mucosal pigmentation and distortion/narrowing of the bronchus. We investigated the occurrence of BAF in respiratory symptomatics with biomass fuel smoke exposure and evaluated its clinico-radiological attributes and impact on functional status. Material and methods: Of the eighty subjects evaluated, 60 consented for fiberoptic bronchoscopy (FOB). All 60 subjects also underwent chest radiography, high resolution computed tomography (HRCT) of the thorax, spirometry with reversibility testing and six-minute-walk test. Information regarding cardinal respiratory symptoms and duration of biomass fuel smoke exposure was documented. FOB evaluation revealed that 24 patients had BAF (Group 1), 17 had bronchial anthracosis (Group 2) and 19 had normal appearance (Group 3). Results: Group 1 patients had significantly higher biomass fuel smoke exposure (p < 0.0001) and lower walk distance (p = 0.003) with greater desaturation. On HRCT, segmental collapse and consolidation were significantly higher in Group 1 while fibrotic lesions were the predominantly seen in Groups 2 and 3. A significant inverse correlation in Group 1 was seen between exposure index, six-minute-walk distance and spirometric parameters. In Group 1, the right middle lobe (RML) bronchus was most commonly involved (15/24 [62.5%]). In Group 2, RML and left upper lobe bronchi were affected in 8/17 (47.1%) patients each. Conclusions: All patients in our study were females. Those with BAF had poorer functional status as compared to those with anthracosis only. On imaging, multifocal bronchial narrowing was specific to BAF.

Bronchial anthracofibrosis: The spectrum of radiological appearances

“…However, there is now a mounting body of evidence to incriminate long-standing exposure to the smoke generated by incomplete combustion of biomass fuel in poorly ventilated kitchens as the causative factor. [ 8 9 10 ]…”

“…The differences between the two entities are summarized in Table 1 . The diagnostic criteria for BAF adopted by us as well as several other authors[ 1 4 5 8 9 10 ] include: (1) long-standing history of biomass fuel smoke exposure, (2) multifocal bronchial narrowing on HRCT when present, and (3) confirmed on bronchoscopy by visualization of (a) bluish-black mucosal anthracotic pigmentation along with (b) narrowing/distortion of the affected bronchus.…”

“…Although BAF is a bronchoscopic diagnosis, imaging often provides the initial diagnostic clue as this clinical entity has diverse but characteristic radiological manifestations. [ 10 12 13 ] The radiological findings in BAF comprise primary imaging features per se due to BAF itself while secondary imaging characteristics are due to the presence of associated disease conditions.…”

“…Radiological features such as multifocal bronchial narrowing and peribronchial cuffing are characteristic of BAF and can be considered as primary imaging features, while collapse, consolidation, and mass lesions could be due to associated conditions. [ 10 13 ] The associated clinical conditions such as pulmonary tuberculosis, chronic obstructive pulmonary disease (COPD), pneumonia, and malignancy contribute to the radiological picture. [ 1 ] Although studies on BAF[ 9 12 13 ] have included radiological aspects, however, a detailed description of the imaging pattern in patients with BAF is yet to receive the attention that it deserves.…”

“…This characteristic feature, when seen on HRCT, is often considered to be the diagnostic hallmark of BAF. [ 1 5 10 11 ] Bronchial narrowing [ Figure 2 ] in patients with BAF tends to be multifocal in nature and usually involves right middle and upper lobe bronchi. BAF affects the segmental or lobar bronchi with sparing of trachea and the main bronchus in most of the patients.…”