Radiology of the aspergilloma

Imaging Spectrum in Chronic Pulmonary Aspergillosis

Chronic pulmonary aspergillosis (CPA) is a life-threatening respiratory fungal infection that is almost exclusively seen in patients with preexisting structural lung disease with no or mild immunosuppression. The clinical presentation and imaging findings are varied and often pose a diagnostic challenge; and the disease is often present for a long time before being correctly diagnosed. High-resolution chest computed tomography is the imaging modality of choice because it helps identify various forms of CPA, which can range from a simple aspergilloma and chronic cavitary form, to the subacute invasive and end-stage fibrotic form. The knowledge of the imaging features of this disease cannot be overemphasized because it can assist the clinician in reaching at an early diagnosis and timely initiation of appropriate antifungal therapy, thereby improving patient management and treatment outcome. Moreover, imaging also plays a pivotal role during follow-up in patients of CPA to assess the treatment response. In the current review, we present an illustrative review of radiologic patterns seen in various forms of CPA.

The radiologic spectrum of pulmonary Aspergillus infections

Aspergillus infections may be categorized by specific radiographic patterns, the patient's immunologic status, and the presence or absence of preexisting structural lung disease. General patterns include invasive aspergillosis (both vascular and airway invasive varieties and acute tracheobronchitis), semiinvasive aspergillosis (including allergic bronchopulmonary aspergillosis and hypersensitivity pneumonitis), mycetoma, allergic aspergillosis, and obstructing bronchial aspergillosis. Knowledge of these various radiographic patterns as well as the immune derangements that accompany these infections may allow proper diagnosis.

Chronic forms of pulmonary aspergillosis

Aspergillus is a genus of fungi commonly found in all environments. Remarkably, only a few species cause disease and equally remarkably, those same species cause multiple diseases. In the lung, exposure to the fungus, the immunological status of the individual and the condition of the lung determine the pattern of disease. In asthmatic patients and those with cystic fibrosis, allergic bronchopulmonary aspergillosis (ABPA) is a complication that reduces pulmonary function and, in asthmatics, is substantially improved by itraconazole therapy. Patients with pre-existing lung cavities develop aspergillomas (fungal masses inside the cavity). Aspergillomas carry a 40% 5 years survival, and it not clear whether antifungal therapy is helpful. Similar in presentation to aspergilloma is chronic necrotizing pulmonary aspergillosis (CNPA). Development of new or expansion of existing pulmonary cavities with surrounding paracavitary shadowing is the hallmark of CNPA These two entities are probably a continuum of the same pathological process. Patients with CNPA respond to systemic antifungal therapy, but this may need to be lifelong. Surgery is appropriate for isolated aspergillomas, but not pleural or multicavity lesions. Aspergillus empyema is a complication of aspergilloma and CNPA, or surgery for these diseases and is slow to respond to treatment.

[Pulmonary aspergillomas. Analysis of 31 patients]

Thirty-one patients with pulmonary aspergilloma were studied retrospectively, leading to the following main findings: 1) Men are most often affected (90% of cases). 2) Diagnosis occurs significantly more often when the patient is between 50 to 60 years of age. 3) Aspergilloma originates most often in residual pulmonary tuberculosis (74% of cases). 4) The incidence of hemoptysis was high (87% of patients). Traditional tomography afforded images that were diagnostically useful in 77.4% of the cases, whereas simple X-rays were useful in only 38.7%. 6) In 94% aspergilloma occurred in the upper lobes. 7) Aspergillus was found in respiratory secretions in 55%. 8) Serum samples were positive for Aspergillus precipitins in 94.4%. 9) Forty-eight percent did not meet criteria for surgical intervention. 10) Noteworthy features of the course of the disease were that spontaneous lysis occurred in 13.6% and that hemoptysis led to death in 9%.

Surgical management of symptomatic pulmonary aspergilloma

Pulmonary aspergilloma is a potentially life-threatening disease resulting from the colonization of lung cavities by the ubiquitous fungus Aspergillus fumigatus. Complex aspergilloma, characterized by thick-walled cavities with surrounding parenchymal inflammation, is a risk factor for increased morbidity and mortality. Fifteen patients with symptomatic aspergilloma underwent major thoracic procedures at North Carolina Memorial Hospital between January 1, 1972, and December 31, 1983. Twelve of the patients had hemoptysis; in 7 it was recurrent and in 5, life threatening. Tuberculosis and sarcoidosis were the most common underlying causes of lung disease, and more than half of the patients had other coexistent serious medical illness. Eleven of the 15 patients were seen with complex aspergilloma; all of the 4 major complications and the 2 deaths occurred in these patients. Bronchopleural fistula with persistent air space was the most common serious complication, and required thoracoplasty in 3 patients. Nine patients, including 5 with complex aspergilloma, had no postoperative complications, and there were no recurrent symptoms in any of the 13 operative survivors over a mean follow-up of five years. It is concluded that aggressive pulmonary resection can provide effective long-term palliation in critically ill patients with symptomatic pulmonary aspergilloma.

Management of pulmonary aspergilloma in the presence of active tuberculosis

Eleven cases of pulmonary aspergilloma complicating active cavitating pulmonary tuberculosis are reviewed. Nine of the 10 patients who had combined medical (antituberculosis drugs) and surgical treatment were cured of their disease; one patient, who had bilateral multiple aspergillomas, died from massive haemoptysis after resection of one of the affected lobes. The only medically treated patient who refused surgery had fatal haemoptysis at home. Pulmonary resection is recommended for patients who are fit for operation whenever the diagnosis of aspergilloma is made because most published reports indicate that only a few patients benefit from drug treatment alone.

Aspergillomas complicating sarcoidosis. A prospective study in 100 patients

During a ten-year study period, we evaluated 100 histologically-proven sarcoid patients for the development of aspergillomas. Serum precipitins against Aspergillus antigens were used to screen all patients regardless of sarcoid stage. Twelve patients had serum precipitins and were further investigated with tomography and serial serum precipitins testing. Ten of these 12 patients had aspergillomas and two patients died of massive hemoptysis. No aspergillomas occurred in stages I, II, or non-cystic stage III patients. All ten aspergillomas developed in the 19 stage III patients with cystic parenchymal damage. We believe that aspergillomas in sarcoidosis are not as rare as previously reported, but occur commonly in chronic cystic sarcoidosis. Additionally, we found serial testing for serum precipitins to be valuable both for the screening of cystic sarcoid patients for aspergillomas and for the management of this complication.

Pulmonary aspergillosis: an analysis of 41 patients

During the period 1969 to 1974, 41 patients having cultures positive for aspergillus were seen on the thoracic surgical services of the University of Maryland and Mt. Wilson State Hospitals. Intracavitary mycetoma was present in 36 patients. In 32 the underlying disease was chronic cavitary tuberculosis, 5 had decreased immunity due to other diseases, and in 3 no underlying disease was noted. One final patient developed a mycetoma following repair of tetralogy of Fallot. Hemoptysis, the predominant symptom, occurred in 23 patients, all of whom were from the group with intracavitary mycetoma. Hemoptysis was life-threatening in 8 patients, severe but not life-threatening in 12, and minimal in 3. Fifteen patients underwent pulmonary resection with 2 deaths. Both patients who died had undergone emergency resection for life-threatening hemoptysis; the fungus ball had developed following a previous resection for tuberculosis, and both had poor pulmonary reserve. Of 10 patients with hemoptysis who were not treated surgically, chiefly because they were poor operative risks, 4 died. This study suggests that pulmonary aspergillosis, particularly of the intracavitary type, is a potentially life-threatening disease. Because of the suddenness with which massive hemoptysis may occur, pulmonary resection is recommended for all patients with intracavitary mycetoma who do not constitute prohibitive operative risks.