aspergillus is a ubiquitous fungus that causes a variety of clinical syndromes in the lung . the type and severity of airway and parenchymal disease produced by aspergillus are influenced by the patient 's immunologic status and the presence of pre - existing lung disease . in recent years , it has been demonstrated that aspergillus infections can result in a broad range of airway complications1 ) . acute pseudomembranous tracheobronchitis is an uncommon form of invasive apergillosis that is usually limited to the large airways and is a newly reported clinical entity2 ) . it has been reported in severely immunocompromised states , such as postallogenic bone - marrow transplantation , malignancy , and aids patients , or in immunodeficient patients associated with t cell dysfunction by influenza a infection3 ) . this report is about a case of pseudomembranous necrotizing tracheobronchial aspergillosis that developed in an immunocompetent host . a 44-year - old korean male presented with a fever , non - productive cough , and myalgias for 10 days . for the previous 5 years , he had been treated for hypertension with an angiotensin - converting enzyme inhibitor . prior to admission , he was treated with oral quinolone for 7 days by the outpatient department , but his condition progressively worsened with resting dyspnea , a productive cough , and a fever for 2 days before admission to the wonkwang university hospital , iksan , korea . the patient was a 30-pack - a - year ex - smoker , and had no history of previous respiratory diseases nor a specific family history . on admission , he had a temperature of 38.6 , blood pressure of 120/80 mmhg , heart rate of 90 b.p.m , and respiratory rate of 30 breaths / min . chest auscultation was significant for bilateral inspiratory coarse , crackles and end - expiratory wheezing around the perihilar areas . arterial blood gas values on room air were : ph 7.343 , paco2 41.2 mmhg , pao2 59.2 mmhg , and sao2 90.7% . the wbc was 19,580/mm ( neutrophils 82.5% ) ; the esr was 71 mm / h ; and the c - reactive protein was 184.6 the blood urea nitrogen was 32.4 mg / dl and the creatinine was 1.32 mg / dl . the random glucose of capillary blood on admission was 117 mg / dl . a chest x - ray obtained on admission demonstrated bilateral bronchial wall thickening with perihilar area and lower lobe predominance ( figure 1 ) . the results of the initial sputum stains and sputum and blood cultures were all negative . the patient received empirical therapy with cefoperazone / sulbactam and vancomycin for 4 days , but rapidly deteriorated with a high fever , increasing dyspnea , and hypoxemia . he developed respiratory failure with severe co2 retention , and was admitted to the intensive care unit and mechanically ventilated . on the fifth day of therapy , chest ct and fiberoptic bronchoscopy were performed because of a rapidly increasing respiratory acidosis with hypoxemia in contrast to the chest x - ray lesions . a chest ct scan revealed only bilateral peribronchial infiltrates with patent bronchi and no consolidation of the parenchyma ( figure 2 ) . a bronchoscopy demonstrated extensive whitish exudative membranes covering the trachea and both mainstem bronchi ( figure 3 ) . the endobronchial biopsy specimens and bronchial washing fluid revealed aspergillus species without parenchymal invasion ( figure 4 ) . a high fever persisted and 2 days later the patient developed refractory septic shock and hypoxemia . despite using iv amphotericin b and supportive care , acute deterioration followed with refractory hypoxemia and oliguria , resulting in a fatal cardiac arrest on the fifth day of the intensive care unit stay . we could not perform a post - mortem examination because of the refusal of his family members . invasive pulmonary aspergillosis ( ipa ) occurs usually following inhalation of aspergillus in the immunocompromised host3 ) . the rate of invasive mycoses has been on the rise recently , and especially invasive aspergillosis among all mycoses increased from 14% to 60% over a 14-year period , probably as a result of greater life expectancies and an increase in the number of immunocompromised patients4 ) . rarely , ipa has been reported in apparently immunocompetent or in mildly immunocompromised patients , such as those with alcoholism , chronic liver disease , and diabetic ketoacidosis3 , 4 ) . because the diagnosis is often delayed for such patients , therefore , invasive pulmonary aspergillosis must be considered in immunocompetent patients with pulmonary infiltrates who do not respond to broad - spectrum antibiotics . acute airway invasive aspergillosis accounts for less than one - third of all cases of invasive aspergillosis5 ) . pseudomembranous necrotizing tracheobronchial aspergillosis has been reported recently as an uncommon form of airway invasive aspergillosis in immunocompromised patients2 , 6 - 8 ) . in a review of the literature on aspergillus tracheobronchitis , including all forms of tracheobronchial involvement , reports indicated that the disease was progressive and fatal in about 40% of cases . it is apparently a lethal variant of tracheobronchial aspergillosis with a markedly higher mortality rate and more parenchymal lung involvement ( 65% ) compared with all cases with aspergillus tracheobronchitis ( 45%)9 ) . it presents with an extensive transmural necrotizing bronchitis with pseudomembrane formation that develops in immunocompromised patients , and it is usually characterized by a limited extension of inflammation and hyphae into the peribronchial tissue , without an invasion of the pulmonary parenchyma2 ) . the pseudomembrane is the whitish membrane or large plugs that occlude the lumen due to the accumulation of hyphae , exudates , and necrotic material . although those are distinct pulmonary entities from aspergillus pneumonia , occasionally , involvement of the bronchial tree can be invasive , leading to a pseudomembranous tracheobronchitis that is associated with extensive bronchial hemorrhage and an invasion of the bronchial walls and vessels . generally , host immune status determines the manifestations of aspergillus lung disease and the response to treatment . patients with aspergillus tracheobronchitismay be less neutropenic and require less exposure to corticosteroids and cytotoxic drugs than patients with parenchymal involvement . in the literature review , 22 cases with this variant of tracheobronchial involvement by aspergillus have been described . to date , there have been only five reports of this disease developing in a immunocompetent or mildly immunocompromised patient . but the first case revealed cutaneous anergy and lymphopenia involving t cells and nk cells , related to a recent influenza a infection10 ) . in the second case , there were " grayish " mucus plugs in several segmental bronchi on autopsy and focally limited extension into the adjacent lung parenchyma8 ) . the third case revealed the presence of a fungal invasion through the bronchial wall into the adjacent lung parenchyma and pulmonary arteries8 ) . the fourth case was a 70-year - old man with risk factors , including corticosteroid use . the last case was a 66-year - old woman whose underlying disease was chronic airway limitation . the present patient had no risk factors associated with an immunocompromised state , and without invasion of the parenchyma , or atelectasis , but who progressed rapidly to severe co2 retention and respiratory failure . to the best of our knowledge , this is a report of a rare case of aspergillus pseudomembranous tracheobronchitis without an invasion of the pulmonary parenchyma that developed in an immunocompetent patient . in this regard , aspergillus tracheobronchitis was confined , at least initially , to the airways with only a superficial mucosal invasion , and the diagnosis is usually delayed because of non - specific signs and symptoms and lack of radiographic abnormalities9 ) . a chest x - ray is not much help in the diagnosis for several reasons , usually because of normal radiological findings : intraluminal mycetomas may not be readily detectable , aspergillus may enlarge so rapidly that recent prior chest radiographs may not reveal atelectasis and the lung parenchyma is usually unaffected1 ) . and radiologically , the only alteration may be the presence of patchy atelectasis related to the mucus plugs . a chest ct scan is a much more helpful tool in the early diagnosis and aids further diagnostic studies , such as bronchoscopies and open - lung biopsies . occasionally , a chest ct scan reveals tracheal or bronchial wall thickening , including opacification of paratracheal fat , tracheal narrowing , and pneumomediastinum in aspergillus tracheobronchitis2 , 11 ) . although a ct scan is helpful in the diagnosis of airway aspergillosis , specific organism diagnosis can not be made on the basis of imaging features alone . bronchoscopy , apart from providing specimens for microbiological examination , is a very useful method for detecting infections with endobronchial manifestations9 ) . bronchoscopic findings are characteristic , revealing focal or diffuse ulcerative or ' plaque - like ' inflammatory lesions ( pseudomembranes ) along the tracheobronchial walls . it should be recommended as early as possible to both diagnose and maintain airway patency at a time when it is most feasible5 , 12 , 13 ) . aspergillus is seen deep to the basement membrane of the bronchioles at histology , and is usually seen within the airway lumen . a presumptive diagnosis is made when the fungus is isolated from bronchial aspirates or bal cultures , and a definitive diagnosis is made when there is histologic demonstration of invasion of the mucosa by hyphae . therefore , culture and histologic examinations of bronchoscopically identified trcheobronchial mucus plugs and necrotic material should be performed in all immunocompromised individuals , even when the main radiographic finding is atelectasis . early detection of intraluminal growth of aspergillus and prompt institution of antifungal therapy may facilitate the management of these patients . in conclusion , as in our patient , the aspergillus infection of the tracheobronchial tree probably contributed significantly to the development of terminal respiratory failure in an immunocompetent patients . although its incidence is rare , pseudomembranous necrotizing tracheobronchial aspergillosis must be considered in immunocompetent patients with dyspnea progressing to severe hypoxemia without an invasion of the pulmonary parenchyma and without a response to broad spectrum antibiotics . therefore , although early recognition of the infection may not have altered the course of the underlying disease in some of these patients , in others , identification and early treatment might have been life - saving .
a 44-year - old korean male died of rapidly progressive respiratory failure and refractory hypoxemia in 8 days after being admitted with a fever and dyspnea . 
 the patient was diagnosed with pseudomembranous necrotizing tracheobronchial aspergillosis by fibroptic bronchoscopy and it was not related to an invasion of the pulmonary parenchyma . to the best of our knowledge , this case represents a patient with pseudomembranous necrotizing tracheobronchial aspergillosis that developed in an immunocompetent host , rapidly resulting in airway obstruction with acute respiratory failure and refractory hypoxemia without an invasion of the pulmonary parenchyma .