Results
Five children were included with the youngest being two years six months and the oldest being 15 years of age, with a prolonged history of fever in all and weight loss in one child. Two children presented with a mediastinal mass and features of superior mediastinal syndrome, and one child each presented with an adrenal mass, midline mass over the bladder and a sigmoid polyp. All five children had localized disease on imaging. Upfront surgery was performed in the three children with abdomen disease, where the polyp was completely excised with negative margins, and 90% of the tumor was resected in the other two. In both the children with mediastinal mass, image-guided trucut biopsy was performed. Morphology was consistent with IMFT for all five children with predominantly myofibroblastic spindle cells in a background of plasma cells, lymphocytes, and eosinophils. Four of the five children were positive for anaplastic lymphoma kinase (ALK) on IHC.
All children received a combination of chemotherapy, which was well tolerated. One patient (child#2) had methotrexate-induced toxicity in the form of raised serum bilirubin around three months after initiation of therapy. As he was in remission, we stopped methotrexate and continued 6MP. Child#5 was kept on the above chemotherapy for three years, given local recurrence on a taper. He is now two years off chemotherapy and is in remission. Child#2 and 3 were on the medications at the time of this publication.
In both the children with residual abdominal disease post-surgery, localized disease recurrence was noted on imaging, following the initial response. They were both started on Crizotinib, which resulted in complete resolution. Crizotinib continued for one year for child # 1 and child # 4 was on the drug for ten months at the time of this publication.
Overall survival in our cohort is 100%, with all children in remission. The longest follow up is five years and the shortest being six months. The details of the five children with their presentations and treatment are elaborated in Table 1. Response evaluations for the children are depicted in Figures 1 and 2. Histopathology and IHC from lung biopsy sample for child#3 are represented in Figure 3.