Inflammatory myofibroblastic tumor mimicking a relapse in a patient with Hodgkin's lymphoma: report of an unusual case and review of the literature

Difficulty differentiating primary mediastinal classical Hodgkin lymphoma from inflammatory myofibroblastic tumor: A case report

A 20-year-old Japanese man visited our hospital because an enlarged mediastinal shadow had been detected on chest x-ray. Chest computed tomography revealed a large mediastinal mass with multiple lymph node enlargement, pericardial effusion, and bilateral pleural effusion. He was diagnosed with inflammatory myofibroblastic tumor (IMT) based on a thoracoscopic tumor biopsy. Initial corticosteroid and celecoxib treatment was only partially effective; therefore, additional tumor rebiopsy and left axillary lymph node biopsy were performed. Based on the findings, the patient was rediagnosed with classical Hodgkin lymphoma (CHL). To date, there has only been one report of a case initially diagnosed as IMT and rediagnosed as CHL, as in our case, and only three reports of malignant lymphoma mimicking IMT. When IMT is suspected based on pathological findings and subsequently with treatment failure, possible CHL and performing rebiopsy should be considered.

Inflammatory myofibroblastic tumor: molecular landscape, targeted therapeutics, and remaining challenges

Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor of intermediate malignant potential that predominantly affects children, adolescents and young adults. IMT has a predilection for the lung, abdomen, pelvis, and retroperitoneum, however, can affect any part of the body. IMT is typically localized, and multifocal or metastatic disease is uncommon. Complete surgical resection is the treatment of choice when feasible. There is no established standard of care for unresectable and advanced IMT. Approximately half of IMTs harbor anaplastic lymphoma kinase (ALK) gene rearrangements, and fusions involving ROS1, PDGFRβ, RET and NTRK have also been described. Given the molecular landscape of IMT, management of these tumors has evolved to include tyrosine kinase inhibitors and novel targeted therapeutics. This review highlights the molecular characteristics, evolution of targeted therapies and the remaining challenges in the management of IMT.

ALK Negative Inflammatory Myofibroblastic Tumor Synchronous with Classical Hodgkin Lymphoma

Inflammatory myofibroblastic tumor or inflammatory pseudotumor was first described by Brunn in 1932. Umiker et al. named it so in 1954 for its ability to mimic malignancy clinically and radiologically [Med Pediatr Oncol 2000; 35(5): 484–7]. This tumor, characterized by its rareness, affects mainly the lung and the orbit. Histologically, the tumor is characterized by the presence of fibroblasts, myofibroblasts, polymorphs, lymphocytes, and neutrophils. This case report and review of literature present a male patient, 37 years old, with a bulky mediastinal lesion at the topography of the 4th rib. Histopathology reveals Hodgkin's Lymphoma (HL) concomitant with inflammatory myofibroblastic tumor (IMT). This report aims to emphasize the relevance of differential diagnoses to a better medical assistance. To the best of our knowledge, a case with this characteristic has never been seen before.