The Primary Ciliary Dyskinesia Computed Tomography Score in Adults with Bronchiectasis: A Derivation und Validation Study.

BACKGROUND: Primary ciliary dyskinesia (PCD) is a rare genetic disorder which requires a complex diagnostic workup. Thus, an easy and widely available screening method would be helpful to identify patients who need a further diagnostic workup for PCD. OBJECTIVES: The aim of the study was to develop and validate a computed tomography (CT) score for PCD to facilitate etiological diagnosis in adults with bronchiectasis. METHOD: Chest CTs from 121 adults with bronchiectasis were scored for bronchiectasis morphology, distribution, and associated findings. Patients with and without the etiological diagnosis of PCD (46 and 75, respectively) were compared. Significantly, different imaging findings (p < 0.05) in univariate analysis were considered for multivariate analysis. Distinct findings were used to build the score. Based on this score, receiver operating characteristic (ROC) curve analysis was performed. The score was validated with 2 independent cohorts, another cohort from the same institution with 56 patients (28 with PCD) and an external cohort from another referral center with 172 patients (86 with PCD). RESULTS: The following parameters predicted PCD in adults with bronchiectasis and were included in the score with weighting according to their regression coefficients: 2 points were given for predominance in the middle/lower lobe, 2 points for tree-in-bud pattern, 2 points for atelectasis or prior resection of a middle/lower lobe, and 3 points for absence of emphysema and fibrosis. Situs inversus was only observed in subjects with PCD (Kartagener syndrome) and, thus, was not used in the primary ciliary dyskinesia computed tomography (PCD-CT) score as group comparisons could not be performed. ROC curve analysis revealed an area under the curve (AUC) of 0.90 (95% CI 0.85-0.96). Youden index was the highest at a threshold of >6 with a sensitivity of 83% and a specificity of 83%. In the validation cohorts, ROC curve analysis confirmed the performance of the score with an AUC of 0.83 (95% CI 0.72-0.94) in the first validation cohort and 0.79 (95% CI 0.73-0.86) in the external validation cohort. CONCLUSIONS: The PCD-CT score provides the first validated CT score for PCD and helps physicians in identifying adult bronchiectasis patients who require further diagnostic workup. Key message: The PCD-CT score provides the first validated CT score to assist physicians in identifying adult bronchiectasis patients who require a further diagnostic workup for PCD. It potentially improves earlier recognition of this rare and underdiagnosed disease.

Rare cause of lung atelectasis in a young woman.

Pulmonary mucoepidermoid carcinoma is an extremely rare intrathoracic malignancy, comprising less than 1% of all lung tumours. These are very slow growing and are classified into low grade and high grade based on histological features. Surgical resection is the primary treatment with excellent outcomes, while chemotherapy or radiotherapy effectiveness is not known. Preoperative fluorine-18 fluorodeoxyglucose positron emission tomography/CT (18F-FDG PET/CT) is useful for predicting tumour grade and postsurgical prognosis.A clinical case of a 31-year-old woman who presented with dyspnoea on exertion, cough and wheezing is reported. Imaging studies revealed a mass involving the left lower lobe bronchus and atelectasis. 18F-FDG PET/CT showed uptake in the described mass with a maximum standardised uptake value of 9.7. Complete surgical resection was performed, and pathological examination revealed a high-grade mucoepidermoid carcinoma with tumour-free margins. Adjuvant chemotherapy was given and there is no evidence of tumour recurrence.

Diffuse idiopathic neuroendocrine cell hyperplasia as a rare cause of chronic cough.

A 39-year-old Caucasian woman, who has never smoked, presented a 16-year-duration chronic dry cough. She was prescribed by her general physician with corticosteroid and long-acting ß-agonist inhalers assuming it was asthma, with mild symptomatic improvement. When cough got more persistent and associated with exertional dyspnoea and wheezing, a chest CT scan was performed, which showed multiple bilateral micronodular formations and diffuse mosaic lung pattern with air trapping. She was sent to our Respiratory Department and performed a bronchoalveolar lavage and cryobiopsy that were inconclusive. She underwent surgical lung biopsy with pathology revealing multiple foci of neuroendocrine cell hyperplasia and tumourlets associated with constrictive bronchiolitis, a histological pattern suggestive of diffuse idiopathic neuroendocrine cell hyperplasia (DIPNECH). DIPNECH is a rare and preinvasive disease. Presenting symptoms can be cough and breathlessness. At the time of writing, the patient is on octreotide with symptomatic improvement.