Abstract A41: Life-threatening pericardial effusion following resolution of transient myeloproliferative disorder (TMD).

Objective: Transient myeloproliferative disorder (TMD) is an abnormal myelopoiesis seen in approximately 10% of newborns with Down Syndrome (DS). It is typically asymptomatic and regresses within 3 months. During active disease, complications include: hepatic fibrosis, organomegaly, bleeding, and pericardial effusions (PE). We report what we believe to be a first case of PE following remission of TMD. Our case involved a 5 week old female infant, former 35 week gestation, with Down Syndrome. On the first day of her life, she had WBC = 36,000 with a left shift and 27% blasts, without organomegaly, consistent with Children9s Oncology Group (COG) “low risk” TMD, and was transferred to our institution. In addition the infant had prenatally diagnosed PE. Both the TMD and the PE resolved prior to discharge at 14 days of life, confirmed by echocardiogram. There was no congenital heart disease or hypothyroidism. The infant was feeding well and gaining weight until she re-presented at 4 weeks of life in cardio-respiratory failure and acidosis, requiring emergency resuscitation secondary to cardiac tamponade. Her initial pH was 6.9 with base excess of -17. She rapidly improved following drainage of the pericardial effusion; repeat pH 1 hour later was 7.32 with base excess -8.7. At the time the CBC and differential was completely normal. The pericardial fluid showed excess of eosinophils (10%) , however there were no blasts. She has done well since that time, with a subsequent normal ECHOs and CBCs. Methods: We conducted a literature search via PubMed for cases of pericardial effusion following resolution of Transient Myeloproliferative Disorder and found no similar cases. Our search included MeSH terms “transient myeloproliferative disorder” and keywords “Down Syndrome review” and “pericardial effusion.” Publications not involving pericardial effusion in Down Syndrome patients were excluded. Results: Our PubMed search of the MeSH term “transient myeloproliferative disorder” with keywords “Down syndrome review” and “pericardial effusion” yielded 55 and 7 articles respectively. PE with active TMD or hypothyroidism is well described in DS patients. The COG trial A2971 identified 10-15% with PE, in the presence of active TMD. Shenoy (2008) and Strobelt (1995) each described cases of pericardial effusion in a Down Syndrome patient with proliferative TMD. Discussion: PE is a known cause of morbidity in TMD when linked to active TMD or hypothyroidism. Pericardial effusion is a known cause of morbidity in TMD and can occur in isolation, however it is extremely rare that it would occur in resolved TMD. There are reported cases of pericardial tamponade in Down Syndrome individuals, but these have been linked to TMD or hypothyroidism. Gamis9 (2011) review of the COG trial A2971, which studied the natural history of TMD, identified mortalities within a risk stratification system, however these patients all had active TMD. Shenoy (2008) described another case of an eosinophilic pericardial effusion in a DS patient, but again, the patient had proliferative TMD. We believe our case is the first description of PE in a patient in remission from TMD. Conclusion: Our case highlights a potentially life-threatening and unexpected sequelae in Down Syndrome patients, with apparently resolved TMD. Future direction could include regularly screening patients with resolved TMD for PE, particularly if there is a history of PE in the past. Citation Format: Nitya A. Narayan, Damien Kenny, Paul Kent. Life-threatening pericardial effusion following resolution of transient myeloproliferative disorder (TMD). [abstract]. In: Proceedings of the AACR Special Conference on Hematologic Malignancies: Translating Discoveries to Novel Therapies; Sep 20-23, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(17 Suppl):Abstract nr A41.