Lymphadenopathy and Upper Airway Obstruction

Abstract

A middle-aged Chinese woman presented to the emergency department with stridor and acute type 2 respiratory failure. She had previously declined surgery for a multinodular goiter diagnosed on ultrasound. Flexible nasoendoscopy showed normal vocal cords and lateral tracheal bulge, presumably from extrinsic compression by the goiter. She was intubated ( Figure 1) and underwent emergent total thyroidectomy to relieve the upper airway obstruction. Intraoperatively, a tumor with features of follicular dendritic cell sarcoma (FDCS) was found, displacing the thyroid and extending retrosternally (Figures 2A-2E). Postoperative 18F-fluorodeoxyglucose positron emission tomography/computed tomography revealed positron emission tomography-avid mediastinal lymph nodes (Figure 3), and the patient was referred for evaluation. Bronchoscopy incidentally showed a polypoidal tracheal tumor 4 cm below the vocal cords, causing 40% obstruction, which was resected with an electrosurgical snare. Tracheal biopsy revealed metastatic FDCS (Figures 4A-4C). Despite chemoradiotherapy, the patient presented 8 months later with near-total airway obstruction by the recurrent tracheal tumor, which necessitated rigid bronchoscopy, neodymium-YAG photoresection, and silicon stent placement ( Figure 5).FDCS is a rare primary lymph node neoplasm arising from follicular dendritic reticulum, with only 100 cases reported. There is growing evidence to suggest a temporal relationship between FDCS and the hyaline-vascular type of Castleman's disease from hyperplasia, dysplasia, and neoplasia, which is evident in our patient's resected tumor ( Figure 2C) (1, 2). Extranodal FDCS has been described in the thyroid, nasopharynx, liver, and retroperitoneum (3, 4) and is not often considered because of its rarity, leading to a misdiagnosis rate of 30% (5). Our unusual case is the first of FDCS masquerading as goiter with upper airway obstruction from presumed extrinsic compression, and subsequently revealing as secondary tracheal tumor. Endotracheal metastasis (6) can occur by invasion from surrounding structures (type 1), from parenchymal lesion (type 2), from mediastinal or hilar lymph nodes (type 3), or from a peripheral lesion that extended along the proximal bronchus (type 4). Tracheal biopsy demonstrating intact epithelium supported type 1 endotracheal metastasis. Surgical resection with adjuvant chemoradiotherapy is the recommended treatment (4), and 27.4% 5-year recurrence-free survival has been reported (5). n Figure 1. Chest radiograph revealed the presence of a prominent left paratracheal stripe (yellow arrow) with an endotracheal tube present.