Too Hot? Don't Believe Me, Just Watch: Highly Positron Emission Tomography-Avid Thoracic Schwannomas

Schwannomas are benign peripheral nerve sheath tumors with characteristic imaging features and low avidity on positron emission tomography (PET). Transformation into malignant peripheral nerve sheath tumors (MPNSTs) is rare (<0.3%), but it typically manifests with invasive, large (>5 cm), PET-avid, heterogeneous tumors. Although schwannomas may be monitored or excised, MPNSTs require aggressive systemic treatment. We present 2 intrathoracic schwannomas with discordant radiologic and pathologic findings, highlighting the preoperative diagnostic uncertainty. These cases emphasize the critical role of multidisciplinary evaluation in guiding management when high PET avidity suggests malignancy despite benign pathologic features.