ALK-Negative Inflammatory Myofibroblastic Tumor: A Challenging Case in a Premature Newborn.

Inflammatory myofibroblastic tumors (IMT) are rare borderline tumors with a variable histological appearance that may mimic multiple mesenchymal tumors. We present a rare case of a challenging abdominal mass discovered in a premature newborn. The histopathology showed a bland myofibroblastic proliferation associated with an inflammatory infiltrate that was positive for smooth muscle actin and desmin but negative for anaplastic lymphoma kinase (ALK) protein.