SESSION TYPE: Airway Cases I
PRESENTED ON: Monday, October 22, 2012 at 01:45 PM - 03:00 PM
INTRODUCTION: Airway smooth muscle hypertrophy is a feature of obstructive lung disorders, including asthma and chronic obstructive pulmonary disease (1). We present a case of bronchial smooth muscle proliferation identified as part of a rare genetic disorder after a hospitalization for respiratory failure.
CASE PRESENTATION: A 55-year-old non-smoking female with a history of esophageal leiomyoma, s/p esophagogastrectomy, uterine leiomyoma, and vulvar leiomyomatosis presented to a local hospital with a two-day history of dyspnea. She declined rapidly requiring intubation and was transferred to our institution for further care. Computed tomography demonstrated no pulmonary embolus and unremarkable parenchyma (Figure 1). Echocardiogram revealed a pulmonary artery pressure of 49-mmHg with right ventricular dilatation. Sputum culture and viral studies returned negative. Laboratory testing was otherwise normal. The patient quickly improved without specific therapy and returned to our outpatient Pulmonary clinic for further investigation. The patient reported several episodes of bronchitis in childhood, with two prior hospitalizations for respiratory infections. She denied chronic cough and sputum production. She endorsed intermittent wheezing. Physical examination was unremarkable. Pulmonary function testing revealed a decreased FEV1 (37% predicted) and FVC (45% predicted) with a decreased FEV1/FVC ratio. Diffusing capacity was reduced (72% predicted). Barium swallow and repeat computed tomography of the thorax were unrevealing. Right heart catheterization demonstrated a mean pulmonary artery pressure of 18-mmHg and a normal cardiac index. Bronchoscopy revealed thickening of the mucosa throughout the tracheobronchial tree (Figure 2). Histopathologic examination of endobronchial biopsies demonstrated smooth muscle hypertrophy of the larger airways. Given the confirmation of smooth muscle proliferation in three organ systems, the patient was referred to a genetic counselor for further testing. Chromosomal microarray confirmed a deletion of Xq22.3 encompassing genes COL4A6 (X-linked diffuse leiomyomatosis) and COL4A5 (Alport syndrome). The patient’s obstructive disease improved with bronchodilators and inhaled steroids.
DISCUSSION: Diffuse leiomyomatosis is a rare phenomenon characterized primarily by hypertrophy of the esophageal wall, but may also involve tracheobronchial wall and female genitalia (2). Tracheobronchial leiomyomatosis has been reported in only four cases at autopsy (2).
CONCLUSIONS: Although airway smooth muscle cell hypertrophy may also be seen in patients with asthma, our case underscores the importance of further investigation when multiple sites of abnormalities are confirmed.
1) Benayoun, L. et. al. Airway structural alterations selectively associated with severe asthma. Am J Respir Crit Care Med 2003;167:1360-1368.
2) Garcia-Torres, R. et. al. Alport syndrome and diffuse leiomyomatosis. Nephrologie 2009;21:9-12.
DISCLOSURE: The following authors have nothing to disclose: Jamie Bessich, James Carroll, Lisa Tilluckdharry
No Product/Research Disclosure InformationDartmouth-Hitchcock Medical Center, Lebanon, NH