Computed Tomography Imaging of the Larynx for Diagnosis of Vocal Cord Dysfunction.

BACKGROUND: Vocal cord dysfunction/inducible laryngeal obstruction (VCD/ILO) is characterized by breathlessness and often mimics or accompanies severe asthma. The disorder occurs intermittently, and the diagnosis is established by using laryngoscopy. Dynamic computed tomography (CT) imaging of the larynx at low-radiation doses has the potential to provide an alternative method to make the diagnosis of VCD/ILO. METHODS: We report two case series: in series A, laryngoscopy (diagnostic standard) and CT imaging of the larynx were each performed within 1 hour of each other (n=31), and in series B, the procedures were performed on separate days 4 to 6 weeks apart (n=72). Diagnosis of VCD/ILO by laryngoscopy used conventional criteria, and diagnosis by CT imaging was based on vocal cord narrowing in excess of a validated normal threshold. In each series, we evaluated the accuracy of CT imaging of the larynx to establish a diagnosis of VCD/ILO compared with laryngoscopy. RESULTS: In series A, the sensitivity of CT imaging of the larynx was 53.8%, and specificity was 88.9%; in series B, the sensitivity of CT imaging of the larynx was 76.2%, and specificity was 93.3%. At a disease prevalence of 30% (which was known to be the case in our clinic), the positive predictive value was 67.5% in series A and 83% in series B. Negative predictive values were 81.8% and 90.1% in series A and B, respectively, and false-positive rates were 11.1% and 6.7%. CONCLUSIONS: When the population prevalence was assumed to be 30%, low-dose CT imaging of the larynx detected VCD/ILO with negative predictive values greater than 80% in both series settings and agreed with each other within 9 percentage points. Positive predictive values for laryngeal CT imaging varied substantially between the settings of the two case series. (Supported by Monash Lung and Sleep Institute and Grant APP ID 1198362 and others.)

[A case of cutaneous vasculitis caused by erlotinib treatment and a review of literature].

Erlotinib is a potent drug used for treating epidermal growth factor receptor (EGFR) mutation positive lung cancer. In this study, we report a case of erlotinib induced cutaneous vasculitis. The patient was a 69-year-old woman with a history of left lower lobe resection for lung cancer. Two years after the resection, she had metastasis in the adrenal glands for which we initiated erlotinib therapy at a dose of 150 mg/day. The patient developed multiple purpurae with a partially necrotic region on both lower thighs at 8 weeks after initiating therapy. The skin biopsy results revealed cutaneous vasculitis. We stopped erlotinib therapy after this diagnosis because of this adverse effect as well as because it exacerbated the cancer. The patient's skin manifestation disappeared 2 weeks after stopping therapy, with no recurrence of any symptoms of systemic vasculitis. We reviewed the literature on drug-induced vasculitis due to oral EGFR inhibitors and found 13 such cases. In most cases, the symptoms appeared 1-2 months after initiating therapy. In all the cases, the symptoms resolved within 2-6 weeks after stopping drug therapy. Erlotinib-induced cutaneous vasculitis is rare but may cause fatal systemic vasculitis. Therefore, the skin of patients who are undergoing erlotinib therapy should be carefully examined at regular intervals during the course of therapy for drug-induced adverse effects.