Efficacy of core biopsies for diagnosing inflammatory myofibroblastic tumors in pediatric patients: case series from a single tertiary referral center

Background: Inflammatory myofibroblastic tumors (IMTs) are rare, often non-metastasizing neoplasms characterized by fibro/myofibroblastic spindle cells with varying infiltrates of plasma cells, lymphocytes, and/or eosinophils. Despite their generally indolent nature, IMTs can exhibit locally aggressive behavior and a significant tendency for local recurrence, making complete surgical resection the standard treatment approach. Accurate diagnosis can be challenging due to the overlap in imaging features with more aggressive tumors, necessitating preoperative biopsies to enable differential diagnosis and guide treatment decisions. The complexity of distinguishing IMTs from other malignancies underscores the importance of biopsy in establishing an accurate diagnosis and planning appropriate management strategies. Case Description: This study presents the cases of four pediatric patients (three males, one female) diagnosed with IMT, involving tumors located in the lung (one case), bladder (one case), and liver (two cases). Initial minimally invasive biopsies, including a US-guided tru-cut core biopsy and a percutaneous core biopsy in one case, as well as endoscopic core biopsies in two other cases, yielded inconclusive results. These initial procedures failed to provide definitive diagnostic information, necessitating the use of more precise diagnostic techniques to achieve a definitive histological diagnosis of IMT. Conclusions: The findings indicate that when initial biopsy results are inconclusive in cases suspected to be IMT, more precise diagnostic procedures may be necessary to secure a definitive diagnosis. This highlights the need for careful consideration of alternative biopsy methods to ensure accurate identification and effective management of IMT in pediatric patients.