The study also evaluated 9 patients (aged 12–31 years, median age 16) treated with methotrexate + vinblastine, methotrexate + vinorelbine, or vinblastine + vinorelbine; 2 patients attained complete responses, 3 attained partial responses, 2 had steady disease, and 2 had progressive disease; this groups progression-free time was not reached while its overall survival time was 83.4 months. The study concluded that the Adriamycin-based and methotrexate/vinblastine/vinorelbine regimens have a high degree of activity in IMT. Due to the low numbers of patients evaluated, no conclusions could be made on which regimen(s) were most effective.In addition to the report that compared the effect of ALK-inhibitors to other therapy regimens detailed in the previous paragraph, several reports have focused primarily on small numbers of IMT patients treated with an ALK inhibitor. The European Organisation for Research and Treatment of Cancer evaluated the effect of the ALK-inhibitor, crizotinib, on 12 ALK-positive IMT adults who had persistent and/or metastatic disease following surgical and/or drug treatment: 2 patients had complete responses, 4 had partial responses, 5 had steady disease, and none had progressive disease; 9 of these patients had at least 1 year of progression-free survival but one patient died of the disease.
Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm of the mesodermal cells that form the connective tissues which support virtually all of the organs and tissues of the body. IMT was formerly termed inflammatory pseudotumor. Currently, however, inflammatory pseudotumor designates a large and heterogeneous group of soft tissue tumors that includes inflammatory myofibroblastic tumor, plasma cell granuloma, xanthomatous pseudotumor, solitary mast cell granuloma, inflammatory fibrosarcoma, pseudosarcomatous myofibroblastic proliferation, myofibroblastoma, inflammatory myofibrohistiocytic proliferation, and other tumors that develop from connective tissue cells. Inflammatory pseudotumour is a generic term applied to various neoplastic and non-neoplastic tissue lesions which share a common microscopic appearance consisting of spindle cells and a prominent presence of the white blood cells that populate chronic or, less commonly, acute inflamed tissues.Inflammatory myofibroblastic tumor was initially regarded as a benign tumor that most often developed in the lung and less commonly in almost any organ system or tissue. Over time, however, IMT cases occurred in which the tumor spread into local tissues, metastasized to distal tissues, recurred after treatment, or consisted of neoplastic cells that had pro-malignant chromosome abnormalities. Consequently, the World Health Organization, 2013, and current literature commonly describe inflammatory myofibroblastic tumor as a neoplasm with intermediate malignant potential or a rarely metastasizing neoplasm. In 2020, the World Health Organization reclassified IMT as a specific tumor form in the category of intermediate (rarely metastasizing) fibroblastic and myofibroblastic tumors.