Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening hyperinflammatory syndrome associated with malignancies, infections, and autoimmune disorders. There are no known complications of hyperammonemia from HLH. Here, we present a patient with B- Acute Lymphoblastic Leukemia (B-ALL), Rett Syndrome, and seizure disorder who presented with septic shock secondary to bacteremia and urosepsis, and subsequently developed HLH. The course was complicated by hyperammonemia of unknown etiology, with possible contributing factors of asparaginase and valproic therapy. Treatment included lactulose, rifaximin, and low-protein diet; ultimately, levels normalized. Recognition of this potential association of hyperammonemia with HLH is crucial in identifying appropriate diagnosis and treatment.

Primary Undifferentiated pleomorphic sarcomas (UPS) of the heart extremely rare but aggressive tumors in the pediatric age group with an extremely poor prognosis and no clear guidelines available for best management. Diagnosis is often delayed, as they may be insidious and masquerade as other cardiac benign tumors. We present a rare case of cardiac UPS in a 13 year old with 40 months disease free survival following a combination of early gross total surgical resection followed by adjuvant chemotherapy and radiation therapy. The case highlights the importance of a timely diagnosis and multimodal multidisciplinary aggressive approach for improved survival.