1. 2012 Texas Pediatric Society Electronic Poster Contest Superior Mediastinal Syndrome as the Initial Presentation of T-Lymphoblastic Lymphoma Shajitha Melethil, MD 1 and Barkat Hooda, MD 2 1 Pediatric Resident – PGY-II, University of Texas Medical Branch, Galveston 2 Director, Division of Pediatric Hematology Oncology, University of Texas Medical Branch, Galveston Superior Mediastinal Syndrome (SMS) is a known complication of pediatric malignancy associated with high tumor burden and occurs at presentation in approximately 12% of the cases. SMS results from direct pressure on vital mediastinal structures including trachea and superior vena cava. This oncologic emergency may be accompanied by respiratory embarrassment resulting in cardiopulmonary compromise. Tumor Lysis Syndrome (TLS) is a biochemical manifestation of the overall presentation of SMS in most cases. To recognize Superior mediastinal syndrome and Tumor lysis syndrome in children presenting with a malignant disorder and learn the rationale for the initial management of these potentially life threatening situations commonly encountered in the tertiary practice of Pediatrics. Initial Vital Signs  BP 125/68 mm Hg, HR 146/min, RR 26/min, Temp 101.3 o F Physical examination at that time revealed bilateral cervical and axillary lymphadenopathy and significantly diminished breath sounds on the left side. Abdominal exam was positive for mild hepatosplenomegaly. Testicles were not enlarged. Initial Lab Results  Hemoglobin-10.2, Hematocrit: 31, WBC-9.7, Platelets-331, ESR-78 mm/hr.  Chemistry revealed essentially normal potassium, creatinine, Uric acid, and calcium.  LFT: liver enzymes normal, Lactate dehydrogenase(LDH) -2632 IU/L A 6 year old male presented to the Urgent Care with a 2 week history of neck swelling and otalgia. Otitis Media was the initial diagnosis and was treated with a course of Amoxicillin without success. Fever, cough, weight loss, and dyspnea developed a week later. He had no other sick contacts or travel history. Chest X-ray (Fig. 1) showed complete opacification of left hemithorax with pleural effusion. Chest CT scan showed a large mediastinal mass (Fig. 2). Echocardiogram confirmed pericardial effusion and Lymph node Biopsy established the diagnosis of T lymphoblastic lymphoma. Due to the concern for respiratory compromise, while performing these invasive procedures, the patient required intubation and anesthesia and had to be monitored in the intensive care unit. He was treated with multi-agent chemotherapy which included Prednisone and intrathecal cytotoxic drugs. After the initiation of chemotherapy there was tremendous improvement in his clinical condition (Fig. 4). Hyperhydration, intravenous Allopurinol and alkalinization of urine effectively prevented Tumor lysis syndrome. The patient went in remission within 4 weeks without any requirement for invasive cardiothoracic surgical procedures. Introduction Case Report Objective Fig 1: Chest radiograph on presentation Fig 2: CT Thorax showing a large superoanterior mediastinal mass with a large left pleural effusion and a small pericardial effusion This case reflects the importance of identifying complex childhood malignancies and its complications as differential diagnosis when a child presents with non specific respiratory symptoms commonly seen in the community Pediatric Practice. Respiratory symptomatology is often the sole presentation of a major cardiothoracic emergency. The most common symptoms of superior mediastinal syndrome in children are dyspnea, cough, dysphagia, orthopnea, and hoarseness. Prompt diagnosis and administration of systemic chemotherapy including steroids in such presentation of a malignant lymphoma is the most important life saving measure. Metabolic complications arising from the breakdown of rapidly proliferating cells causing life threatening hyperuricemia, hyperkalemia, acidosis and hyperphosphatemia leading to renal insufficiency (TLS) should be anticipated by medical staff including residents upon admission of the patient and appropriately managed. Discussion Fig 3: Chest radiograph 2 weeks after initiation of chemotherapy Fig 4: Serial LDH monitoring indicating resolution to normal range Recognizing and managing critical conditions like SMS and TLS at an the early stage of presentation will significantly reduce morbidity and mortality in a child presenting with cancer and may minimize unnecessary surgical interventions and intensive monitoring. Understanding the need for the judicious use of limited health care resources will cut costs associated with patient care and allow those resources to be used for other patients and services improving our utilization of health care dollars. Conclusions References  Fisher MJ, Rheingold, SR. Oncologic Emergencies. In: Principles and Practice of Pediatric Oncology, 6th, Pizzo, PA, Poplack, DG (Eds), Lippincott Williams and Wilkins, Philadelphia 2011. p.1125.  Ahn YH, Kang HJ, Shin HY, Ahn HS, Choi Y, Kang HG. Tumour lysis syndrome in children: experience of last decade. Hematol Oncol. 2011 Dec;29(4):196-201. doi: 10.1002/hon.995. Epub 2011 Jun 24.  King RM, Telander RL, Smithson WA. Primary mediastinal tumors in children. Journal of Pediatric Surgery 1982; 17:512-520.  Kam-Lun Ellis Hon, Alex Leung, Ki-Wai Chik, Chiu- wing Winnie Chu, Kam-Lau Cheung, Tai Fai Fok Critical airway obstruction, superior vena cava syndrome, and spontaneous cardiac arrest in a child with acute leukemia. Pediatric emergency care (impact factor: 0.92). 01/2006; 21(12):844-6.  Ingram L, Rivera GK, Shapiro DN Superior vena cava syndrome associated with childhood malignancy: analysis of 24 cases. Med Pediatr Oncol. 1990;18(6):476.