Chen, Jun

Abstract Introduction Mediastinal masses may exhibit various clinical and pathological features. Posterior mediastinal lesions are often neurogenic, followed by lymphadenopathy, extramedullary hematopoiesis, paraspinal abscess, and rarely, foregut duplication cysts (prevalence: 0.122%). Given the rarity and diagnostic challenges, these masses are often biopsied, though may not be ideal. We present a case of esophageal duplication cyst (EDC). Case presentation A 33-year-old woman with mild intermittent asthma, had initially presented to an outside facility for chronic productive cough, episodic chest tightness and dyspnea both at rest and with exertion, inspiratory and expiratory wheezes. Despite multiple courses of prednisone for presumed asthma exacerbation, her symptoms persisted. An initial Computer Tomography (CT) Chest demonstrated a 5 x 4 x 3 cm mass within the visceral mediastinum. Bronchoscopy with endobronchial ultrasound and transbronchial needle aspiration of the mediastinal lymph nodes was nondiagnostic, showing scant lymphocytes and abundant mucin. Broad autoimmune, connective tissue disease, and infectious disease workups were negative, prompting referral to our facility. Physical exam and labs were unremarkable and pulmonary function testing showed no evidence of small airway obstruction. A High-Resolution CT Chest revealed a 3.1 x 3.7 x 4.5 cm noncalcified, well-circumscribed mass soft tissue density, adjacent to the esophagus with elevated Hounsfield units close to esophagus. Ultimately duplication cyst was suspected and Magnetic Resonance Imaging (MRI) with contrast showed high T1 and T2 signal within the lesion and no enhancement after contrast, deemed compatible with proteinaceous/hemorrhagic cyst (Figure 1 A-D). Biopsy was deferred given diagnostic MRI characteristics, and risk of secondary infection. The diagnosis of EDC was confirmed via multidisciplinary thoracic tumor board revision. Ultimately, she was referred for surgical resection. Discussion The incidence of EDC is 1 in 8,200, with a two-fold male prevalence over women. These patients may present with dysphagia, cough, stridor, pain, or arrhythmia since childhood, or may be entirely asymptomatic. EDCs can develop along the esophagus, with 90% lacking communication with the esophageal lumen. Although posterior mediastinal mass typically require biopsy to exclude malignancy, tissue biopsy should be avoided in cases with suspected duplication cyst given risk of infection, abscess formation and mediastinitis. Transesophageal endoscopic ultrasonography could further characterize the cyst, however MRI is considered the gold standard diagnostic modality. Conclusion MRI is the gold standard diagnostic modality of EDC. Biopsy should be avoided given the risk of infection. Clinicians should consider a broad differential for posterior mediastinal mass and avoid unnecessary invasive testing.

Abstract Introduction Unilateral pulmonary vein atresia (UPVA) is a rare congenital anomaly involving absent or obstructed pulmonary veins (PV), often leading to chronic pulmonary venous stasis, recurrent infections, and hemoptysis. Although typically diagnosed in infancy, UPVA can present in adulthood. This report presents a 63-year-old male referred as a case of chronic thromboembolic pulmonary disease (CTEPD) who was diagnosed with UPVA. We describe the diagnostic complexities and potential explanation for loss of pulmonary artery (PA) perfusion in such cases. Case Presentation A 63-year-old man was referred to rule out CTEPD. His past medical history included coronary artery disease and sleep apnea. He presented with chronic cough, repeated hemoptysis, recurrent pneumonias requiring prolonged antibiotics use, and progressive exertional dyspnea. Physical examination was unremarkable. Pulmonary function tests showed moderate restriction and moderately-reduced diffusion capacity. A ventilation-perfusion (V/Q) scan revealed complete absence of perfusion in the left lung. [figure1] High-resolution CT revealed a straight left atrial border sign with absent left superior and inferior PVs, left pulmonary arterial tree hypoplasia, hypoplastic left lung with fibrotic changes due to chronic venous-lymphatic engorgement and pulmonary hypoperfusion. CT also showed compensatory right lung hyperinflation and bronchial artery collaterals. Echocardiography indicated an atrial septal defect (ASD) with no pulmonary vascular disease. Based on CT angiography, UPVA was considered the leading diagnosis. Discussion UPVA is a congenital disease rarely presenting in adulthood with recurrent infections, hemoptysis, and fibrosis. It often accompanies congenital cardiac conditions, like ASD in our case. Pulmonary angiography may reveal ipsilateral PA hypoplasia and atrophied peripheral vessels. The absence of perfusion in the V/Q scan could be explained by reversed blood flow in the PA from congestion caused by the atretic PVs and ipsilateral backflow from the bronchial arteries collaterals. Differential diagnosis like CTEPD was excluded due to atypical complete loss of perfusion of the left lung, and lack of the other radiological stigmata. Swyer-James-MacLeod syndrome was excluded due to a mismatched perfusion defect. Proximal Interruption of the PA was also excluded due to normally developed proximal left and right PAs. Imaging is crucial in showing absent PVs and hypoplastic ipsilateral lung. Conservative management for UPVA is recommended. Given recurrent infections and hemoptysis, pneumonectomy can be considered. Conclusion This case illustrates the atypical presentation of UPVA as a CTEPD mimicker, presenting with absent pulmonary perfusion unilaterally, which can be explained by reversed pulmonary flow secondary to venous engorgement and backflow from bronchial artery collaterals. Figure1: