CASE 8921 Published on 17.11.2010

Chronic loculated thoracic empyema with fade and nonspecific infectious symptoms in an elderly patient with diabetes mellitus

Section

Chest imaging

Case Type

Clinical Cases

Authors

Mantarro A, Bemi P, Sighieri E, Vagli P, Neri E, Bartolozzi C.

Patient

80 years, male

Categories
Area of Interest Lung, Respiratory system ; Imaging Technique Conventional radiography, CT-High Resolution
Clinical History
An 80 year old man, with diabetes mellitus type II and poor glycaemic control, came to our attention for complaints of asthenia and slight rise in body temperature.
Physical examination revealed slenderness and overall decrease in muscle mass due to under nutrition. Laboratory tests displayed anaemia and modest increase in white blood cells.
Imaging Findings
Chest radiography showed an opacity in the lower left lung zone in close proximity to the chest wall, probably due to a loculated pleural effusion, hilar calcified lymph nodes and no signs of pleuroparenchymal lesions in the right lung (Fig. 1).
CT examination revealed a loculated and lenticular-shaped pleural effusion, encapsulated by thickened and partly calcified pleural sheaths, adjacent to the left chest wall and extending toward the lateral costophrenic angle, which was suggestive of chronic empyema. CT displayed also an atelectatic area contiguous to the pleural effusion, involving the inferior lingular segment and pulmonary hilum, hilar lymph node calcifications and absence of patency of lingular bronchi (Fig. 2).
A follow-up chest radiograph, carried out 6 months later, confirmed the loculated pleural effusion with parietal pleural calcifications, already referred to as chronic empyema. In addition, the radiography showed a collection of free pleural fluid in the basal area of the left lung (Fig.3).
Discussion
Thoracic empyema is an overt pus collection within pleural space [1]. It may result from primary pleural infection or be secondary to: a) infectious spreading from adjacent or distant foci; b) infection by penetrating injuries or surgical procedures; c) other conditions (e.g. diabetes mellitus, drug abuse) [2-3].
Symptoms include dyspnoea, productive cough, chest pain, fever and weakness [3-4]. Typical presentation can be suppressed in patients with chronic debilitation or immunodeficiency (“silent” empyema), with difficult diagnosis [3].
Chest radiograph represents the best initial screening procedure, in which the exudative pleural effusion appears as an opaque area, frequently with loculation and air-fluid levels. Chronic loculated empyema displays oblong opacity, similar to a mass ascribable to lung cancer or mesothelioma, with possible calcifications of pleural sheaths [2].
Chest ultrasound provides information on fluid collection and presence of septations/ loculations, allowing guided-thoracentesis [4-5].
CT scan represents the most suitable method for: assessing overall pleural surfaces; determining the extent of pleural involvement and nature of fluid collection; studying underlying lung parenchyma, mediastinum and chest wall; positioning chest drainages; selecting therapeutic approaches. As compared to other methods, CT is more sensitive for detecting small pleural effusions, discriminating them from peripheral parenchymal infiltrates or pleural thickenings, and exploring ultrasound inaccessible areas [4-5].
Typical CT appearances of loculated empyema include: elongated shape with thin and smooth walls; compression of adjacent lung parenchyma; fluid separation of pleural sheaths, with occurrence of ‘‘split pleura sign’’. These findings help to differentiate empyema from pulmonary abscess, which appears as a spherical mass with poorly defined walls, surrounded by consolidated lung. Moreover, its interface angle with chest wall is acute, while empyema forms an obtuse angle [3].
Early diagnosis of thoracic empyema is essential for a better prognosis, as it avoids chronicity, usually occurring after 4-6 weeks in the absence of adequate treatment, and complications, including broncho-pleural fistula, chest wall erosion, fibrotorax, multi-organ failure [3].
In our patient, empyema development and chronicity were likely promoted by aging and immunodeficiency, resulting from under nutrition and diabetes [6]. Indeed, diabetes with poor glycaemic control determines immunologic depression, mostly related to polymorphonuclear dysfunction, with consequent increase in the risk and severity of infections [7]. Moreover, in elderly patients with comorbidities, as in the present case, empyema symptoms can be scant and nonspecific, resulting in delayed diagnosis with prolonged hospitalization, invasive therapeutic procedures, compromised quality of life, and increase in morbidity and mortality [6-7]. In this respect, the statement of Hippocrates remains still actual: “If an empyema does not rupture, death will occur” [8].
Differential Diagnosis List
Chronic loculated thoracic empyema
Pulmonary abscess
Mesothelioma
Lung cancer
Final Diagnosis
Chronic loculated thoracic empyema
Case information
URL: https://www.eurorad.org/case/8921
DOI: 10.1594/EURORAD/CASE.8921
ISSN: 1563-4086