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A4099 - A New Diagnosis of Neurofibromatosis Type 1 in a Young Adult Male Presenting with Palpitations and Posterior Mediastinal Mass
Author Block: S. Giancaterino1, D. Vargas Valdivieso1, P. Akuthota2; 1Medicine, University of California, San Diego, La Jolla, CA, United States, 2Pulmonary and Critical Care, University of California, San Diego, La Jolla, CA, United States.
Introduction: Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder, often first presenting with oculocutaneous findings in children. Neurofibromas are the most common benign tumors found in NF1 and can be found both superficially and deep inside the body.
Case Presentation: A 19 year old Hispanic male college student presented with symptomatic palpitations and a persistent dry cough. He had experienced intermittent episodes of palpitations monthly over the past year. Past medical and family history were unremarkable.
Vital signs were notable for mild tachypnea and tachycardia in the 170s with an irregularly irregular rhythm. He had coarse bilateral rhonchi and inspiratory wheezing. Skin exam revealed multiple cafe-au-lait macules (CALMS) to the lower back/buttocks and freckling to the bilateral axillary and inguinal regions. Initial labs were unremarkable. EKG showed atrial fibrillation with HR in the 170s. Echocardiogram revealed a mass in the posterior pericardium compressing the left atrium and basal posterior LV wall. CT chest showed a mass in the posterior-middle mediastinum in both hilum compressing bilateral pulmonary arteries and posterior margin of the left atrium. Biopsies taken during cervical mediastinoscopy ultimately revealed plexiform neurofibroma.
Hospital course was complicated by refractory sinus tachycardia and acute hypoxic respiratory failure secondary to left main bronchus compression. The patient underwent open thoracotomy with excision of mediastinal mass and recovered well. He was discharged home with close follow up. During this admission the patient was tentatively diagnosed with NF1, previously unknown to him and his family. This diagnosis was later confirmed by neurology, oncology and medical genetics specialists in the clinic.
Discussion:
Direct tumor compression of mediastinal structures can be the first symptom of a chest mass. The differential for mediastinal mass in an adult is broad, and it is useful to categorize anatomically by the anterior, middle, and posterior compartments. Anterior masses are more commonly recognized by trainees and physicians by the “5 T’s” mnemonic. Posterior masses are most often neurogenic tumors, including neurofibromas.
NF1 is diagnosed clinically by the NIH criteria, requiring two or more of six criteria be met. This patient met three during his initial presentation with: 1) CALMS meeting size criteria, 2) axillary/inguinal freckling, and 3) pathologic diagnosis of plexiform neurofibroma. While often thought of as peripheral nerve or cutaneous tumors, plexiform neurofibromas can be found deep inside the body and have rarely been reported to invade the pericardium such as in this case.