The role of autofluorescence bronchoscopy in monitoring a tumorous lesion in the bronchial mucosa : a case report

Introduction. Autofluorescence bronchoscopy (AFB) is a diagnostic procedure that is included in all diagnostic algorithms discovering precancerous lesions in the large airways. Case report. We presented a 71-year-old patient submitted to exploration due to prolonged cough. Both noninvasive and invasive pulmonary diagnostic management was carried out. On bronchoscopy, an endobronchial mass was detected in the apical bronchus. A positive endoscopy finding indicated AFB which disclosed a fluorescence alteration of the tumor mucosa and the former bronchoscopy site. Histopathological analysis of the catheter biopsy obtained samples from the right upper lobe confirmed fibrinous purulent pneumonia in organization. The applied treatment resulted in regression of both symptoms and the lesion in the right upper lobe. Due to a positive AFB finding, the patient was regularly observed over the following three years, having had three control AFB to monitor the initial finding. Conclusion. AFB may be utilized in the routine of everyday practice to assess the spread of the disease, as well as in the postsurgical and long-term follow-up of operated patients. The procedure may also be applied to enable an easier and more reliable observation of patients with suspicious endobronchial lesions, smokers with altered fluorescence of the bronchial mucosa, and chronic patients.


Introduction
Lung cancer is the most common death cause in patients with malignant diseases.The treatment of choice in these patients includes early diagnosis and a radical tumor resection.There is a great interest to develop imaging tech-niques which might detect the slightest lesion in the mucosa of the airways.Autofluorescence bronchoscopy (AFB) is a relevant diagnostic procedure included in all diagnostic algorithms to discover precancerous lesions in the large airways, like metaplasia, dysplasia, carcinoma in situ and microinvasive cancer 1 .

Case Report
A 71-year-old male patient was examined in the Institute for Pulmonary Diseases of Vojvodina in Sremska Kamenica, in May 2008.The patient had gradually developed the symptoms of fatigue and productive cough without blood traces, reporting a 30 pack-year smoking history.The patient's chest X-ray finding revealed a non-homogeneous shadowing in the right suprahilar region, projecting in the upper lobe (Figure 1).
Computerized tomography of the chest was performed, disclosing an irregular, infiltrative lesion of the density of 40 Hu in the third segment of the right lobe, next to the incisure.The mediastinal lymph nodes were not enlarged (Figure 2).
Bronchoscopy was performed.The larynx, trachea, bifurcation and the left bronchial tree had a normal endoscopic finding, as well as the right main bronchus, intermediary bronchus and lower bronchi.However, a tumorous lesion was seen in the apical segment.Histopathology of the bronchial biopsy obtained from the right upper bronchus, as well as of the biopsy from endobronchial mass and the sample obtained by transbronchial needle biopsy via the right upper bronchus provided a purulent exudate and established the histological elements of chronic nonspecific inflammation, with no elements of tumor tissue.The positive endoscopic finding indicated hospitalization.

Fig. 2 -Computed tomography scan findings of the chest did not reveal enlarged mediastinal lymph nodes
scopically the superior bronchus was involved by a gelatinous tumorous formation which entirely obstructed the orifice for the apical segment.AFB revealed an altered fluorescence of tumor mucosa and the former bronchoscopy site (Figure 3).Histopathological analysis of the bronchial biopsy sample obtained from the right upper bronchus confirmed fibrinous purulent pneumonia in organization (Figure 4).No tumorous tissue was found in the examined sample.

Fig. 4 -Histopathological finding: fibrinous purulent pneumonia in organization (hematoxylin-eozin, 400×)
The patient responded well to the applied antibiotic therapy and corticosteroids (prednisolone tablets in the dose of 30 mg) accompanied with H 2 receptor antagonists.Rehabilitation treatment with breathing exercises was also carried out.The control chest computed tomography (CT) finding showed considerable regression of the lesion in the right upper lobe.The control inflammation markers were within normal levels, including erythrocyte sedimentation rate (10/-), white blood count (7.1 × 10 9 /L).C reactive protein (<6 mg/L), fibrinogen (3.5 g/L).The patient was discharged for further home treatment, with recommendations for control examination and bronchoscopy indicated by a positive autofluorescence finding.
The patient came for control six months later.On physical examination, the patient was entirely asymptomatic, but his chest X-ray finding was presented with more voluminous hilly and bilateral striped shadows pericardially (Figure 5).

Fig. 5 -Posteroanterior chest X-ray finding six months after discharge revealed more voluminous hilly and bilateral striped shadows epricardially
Laboratory test findings, pulmonary gas exchange and lung function test findings were normal as well.The control chest CT finding delineated a discrete zone of hypodense lesions in the right upper lobe corresponding to post inflammatory lesions (Figure 6).Bronchoscopy was performed.Two tiny granulations were observed in the upper arch of the right bronchus, as well as a wider intersegmental with all orifices free.AFI detected no altered fluorescence of the granulations, unlike the altered fluorescence of the mucosa in the intersegmental carina, between the posterior and anterior orifices (Figure 7a).
The histopathological and cytological analysis of the samples showed no elements of tumorous tissue.The patient was suggested to have a control bronchological exploration in six months.
At the control six month later, the patient reported no subjective symptoms.The chest X-ray finding showed no deviations from the former one.A control bronchoscopy was performed, providing a normal endoscopic finding.In the bronchus for the right upper lobe, on its lateral wall towards the orifice for the posterior one, a tine granulation was detected.AFB revealed the altered mucosa on the intersegmental carina in the right upper lobe, at the possible site of the former biopsy.The granulation did not fluoresce (Figure 7b).
The control bronchoscopy was performed one year later with normal endoscopic finding.The patient reported no symptoms.The radiological finding was unchanged.Laboratory test findings were within normal levels.Pulmonary gas exchange, spirometry and plethysmography findings were normal.The formerly detected granulations were not delineated.Autofluorescence showed fluorescence of sites of former biopsy at one point of the carina of the upper bronchus, as well as on the intersegmental carina.The histopathological analysis showed usual histological elements.The patient was dismissed with a recommendation to continue with regular observations in the future.

Discussion
The investigations performed so far have very well established that AFB achieves better results in detecting pre-cancerous lesions than conventional bronchoscopy.Many multicentric studies have revealed that AFB performed in combination with a standard one, increases the percentage of early detected dysplasia, cancer in situ and microinvasive lung cancer [2][3][4][5][6][7][8][9] .It has been confirmed that the lesions in terms of metaplasia, dysplasia, dysplasia and carcinoma in situ may appear over large mucosa regions of the tracheobronchial tree, particularly in smokers and patients with invasive diseases 9,10 .The studies having been carried out since 1990 using AFB to diagnose premalignant lesions of the central airways have confirmed that premalignant lesions' behavior is unpredictable.Certain advanced lesions, defined as "carcinoma in situ" have exhibited the capacity of spontaneous regression 11 .AFB has a higher potential than the conventional, white-light bronchoscopy.Recent studies have shown that it may be applied in the routine of everyday practice to assess the spread of the disease 12,13 .
Nowadays, there is a great debate about a large-scale application of AFB in the screening of lung cancer.Any new procedure requires a detailed analysis and assessment of possible negative effects on a patient.

Conclusion
When applied in combination with a standard bronchoscopy, AFB increases early detection of premalignant lesions, dysplasia, carcinoma in situ and micro invasive lung cancer.This method may be used in the routine of everyday practice to assess the spread of the disease, in the postoperative monitoring and a long-term follow-up of surgically treated patients.In addition, it may also be utilized to enable an easy and more reliable observation of patients with suspicious endobronchial lesions, as well as in smokers and chronic patients with altered mucosa on fluorescence.

Fig. 6 -Fig. 3 -
Fig. 6 -Control chest computed tomography finding: discrete zone of hypodense lesions in the right upper lobe

7 -
Endoscopy findings of autofluorescence bronchoscopy a -no altered fluorescence of the granulations and altered fluorescence of the mucosa in the intersegmental carina (first control six month after disharge) b -the altered mucosa at the possible site of the former biopsy (second control six month after the first post-disharge control)