Distinguishing Benign Notochordal Cell Tumors From Chordoma in a Patient With Multicentric Spinal Lesions

This case report details a 60-year-old man who presented with several spinal lesions after they were discovered incidentally during abdominal CT imaging. Lesions were observed in the cervical and thoracic spine and sacrum (C2-C3, C3-C4, C5-C6, T3, T4, T8-T9, S2-S3, and S4 levels) with varying bone involvement, soft tissue extension, and appearance on CT and MRI. The dominant lytic T8-T9 lesion was biopsied, resulting in a diagnosis of chordoma, yet ¹⁸F-FDG PET/CT showed no significant FDG activity in this lesion or elsewhere. Other lesions were not biopsied, and all lesions were subsequently monitored with routine imaging. Over the next several years, the lesions continued to show long-term stability on MRI with no symptomatic progression. Due to their longstanding benign nature, the unbiopsied lesions were reevaluated as a more benign etiology, such as benign notochordal cell tumors (BNCTs), which are also derived from notochordal remnants and are hypothesized as a precursor lesion to chordomas, but differ in their clinical behavior, histopathological characteristics, and imaging features. Accurate differentiation between BNCTs and chordomas is imperative for guiding treatment strategies, especially in the very rare case of multiple confounding lesions, as seen in this patient. This report underscores the diagnostic challenges in differentiating BNCTs and chordomas and highlights the importance of correlating histopathological findings with clinical and imaging features for accurate interpretation and intervention.