Laryngeal heterotopic ossification: An atypical etiology of respiratory distress

Tracheobronchopathia osteochondroplastica is a rare disease characterized by submucosal osteocartilaginous nodules projecting into the tracheal lumen. Although this disease commonly involves the distal trachea, there have been rare reports of laryngeal involvement. We present an unusual case of diffuse heterotopic ossification with an initial chief complaint of respiratory distress. Subsequent computed tomography imaging demonstrated widespread laryngeal ossification and biopsy of the tracheal cartilage demonstrated osseous metaplasia. This report of heterotopic laryngeal calcification offers management options directing care of what may represent a variant of tracheobronchopathia osteochondroplastica. INTRODUCTION Tracheobronchopathia osteochondroplastica (TPO) is a rare benign disease of the tracheobronchial tree, consisting of submucosal osteocartilaginous nodules projecting from the underlying cartilage into the tracheal lumen. The nodules range in diameter from 1 to 10 mm and usually remain stable or progress very slowly. Consequently, most cases present asymptomatically and are incidentally diagnosed on bronchoscopy, imaging studies, or autopsy. Moderate or severe disease may alter the normal airway anatomy, causing airway obstruction and defective mucociliary clearance. Common symptoms include chronic cough, hemoptysis, hoarseness, dyspnea, and recurrent respiratory infections. TPO has an equal rate of incidence between males and females and is most commonly diagnosed during the sixth decade of life. This condition characteristically involves the anterior and lateral walls of the airway and spares the posterior membranous wall, allowing the disease to be distinguished from other airway diseases including tracheobronchial amyloidosis, endobronchial sarcoidosis, and papillomatosis. Whereas the majority of cases involve the distal two-thirds of the trachea, there have been isolated case reports of extratracheal heterotopic ossification. We present a rare case of laryngeal heterotopic ossification presenting with respiratory distress. CASE REPORT A 45-year-old female with a history of asthma and Crohn’s disease presented to the emergency room in respiratory distress. She reported a history of progressive hoarseness over 1 year and worsening stridor over 6 months. Prolonged talking and physical activity aggravated her symptoms. Breathing treatments and rescue inhalers for her asthma did not alleviate the hoarseness and stridor. She denied prior difficult or prolonged intubations, trauma to the neck, or prior neck surgeries. Assessment at our institution included pulmonary function testing that showed a fixed extrathoracic obstruction pattern and decreased peak inspiratory flow. Distalchip flexible laryngoscopy confirmed paralysis of the right true vocal cord (Fig. 1). Neck computed tomography showed fusion of the hyoid to the thyroid cartilage, right cricoarytenoid fusion, bilateral cricothyroid fusion, and a bony spur into the anterior commissure from the thyroid cartilage (Fig. 2). Tracheal calcification was identified during a tracheostomy performed under local anesthesia. Direct laryngoscopy following conversion to general anesthesia revealed right vocal fold fixation, left vocal fold mobile to palpation, and confirmed the absence of a mucosal lesion. Biopsy specimens obtained from the tracheal From the Department of Pathology (R.L.E., R.A.R.), the Department of Otolaryngology–Head and Neck Surgery (J.W., H.T.H.), and the Department of Radiology, Division of Nuclear Medicine (P.S.M.), University of Iowa Hospitals and Clinics, Iowa City, Iowa, U.S.A. Editor’s Note: This Manuscript was accepted for publication July 29, 2016. Presented as a poster at the 2016 Triological Society Combined Sections Meeting, Miami Beach, Florida, U.S.A., January 22–24, 2016. The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Renee L. Eigsti, MD, Department of Pathology, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA 52242. E-mail: renee-eigsti@uiowa.edu DOI: 10.1002/lary.26267 Laryngoscope 127: May 2017 Eigsti et al.: Laryngeal Heterotopic Ossification