Teaching Case

A 56-year-old immunocompetent Caucasian woman presented with chronic cough. She was an active smoker (3 pack years) and had no known environmental expositions. She presented basal rales and rhonchi at physical examination.

Computed tomography of the chest showed right middle lobe chronic volume loss with architectural distortion and bronchiectasis, with scattered mucous plugging and endobronchial calcification. There was also similarly distributed scattered tree-in-bud nodularity and ill-defined centrilobular nodules.

There was no significant emphysema, focal consolidation, cavitary nodules, or pleural effusion or thickening.

Findings were in keeping with small-airways disease, possibly due to non-tuberculous mycobacteria (NTM).

Lady Windermere Syndrome (LWS) is an atypical presentation of Mycobacterium avium complex (MAC) pulmonary disease. First described in 1992, this NTM lung disease is recognised in the official statement of the American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA) regarding its diagnosis and treatment [1,2].

Contrary to the traditional presentation seen in immunocompromised middle-aged males with a smoking history and underlying lung disease, LWS presents in healthy non-smoking elderly white women with no underlying pulmonary disease. It presents as a slowly progressive disease with nonspecific respiratory symptoms such as chronic cough and dyspnoea [1,3–5].

Since it has a nonspecific clinical presentation, clinicians should suspect it as one of the possible differential diagnoses in patients presenting chronic cough. Therefore, it is recommended that the evaluation should include a chest image, preferably a CT scan [2].

Radiological presentation typically involves the right middle lobe or lingula. This infection is an excellent example of cellular bronchiolitis, which damages the small airways. CT findings are broad, including multiple small peripheral centrilobular nodules, usually in a “tree-in-bud” pattern, diffuse opacities and cylindrical bronchiectasis [2].

Although not always possible, diagnosis is confirmed with positive sputum cultures for MAC. The most recent ATS/IDSA recommendation for treatment consists of a three-drug regimen of clarithromycin or azithromycin, ethambutol and rifampicin given intermittently three times weekly until 12 months of culture-negative sputum [2].

This clinical case partially fits the typical patient description of LWS, being a middle-aged immunocompetent Caucasian woman with a history of chronic cough. Although she had a long cigarette smoking history, her lung did not show smoking-related lung damage. Her chest CT shows the classical LWS radiologic pattern, middle lobe compromise with chronic pulmonary atelectasis, traction bronchiectasis and multiple centrolobulillar nodules, confirmed with sputum cultures positive for MAC.

In recent years, NTM diseases such as LWS have received an unprecedented level of interest. Improvements in diagnostic techniques have shown this disease in patients with different characteristics as the ones typically described in literature. Because of that, there needs to be a high index of suspicion when dealing with patients presenting nonspecific chronic pulmonary symptoms, relying on radiological and CT findings in the evaluation process of these kinds of patients [2].

Written informed patient consent for publication has been obtained.