We report a case of a 3-year-old boy with hemophagocytic lymphohistiocytosis (HLH), with enlarged cervical lymph nodes causing internal jugular vein compression, who initially presented a condition similar to the superior vena cava syndrome. Laboratory data along with neck node and bone marrow biopsies confirmed the HLH. Genetic analysis revealed the patient to be compound heterozygous for 2 variations of the perforin gene, c.1620 A>G and c.562C>G. This case featuring a rare initial manifestation of HLH that has not been previously reported, points to the necessity of considering this disease when symptoms similar to superior vena cava syndrome are encountered.