The Expression And Clinical Significance Of ALK Gene In Extra-Pulmonary Inflammatory Myofibroblastic Tumor

Objective:To summarize the the clinical features of Extra-Pulmonary Inflammtory Myofibroblastic Tumor in Children, improve the diagnostic standards. Investigate in the expression of anaplastic lymphoma kinase protein in Extra-pulmonary inflammatory myofibroblastic tumor, and provide a theoretical basis for the clinical diagnosis, treatment and prognosis of IMT.Methods:Retrospective reviewed clinical data of19cases of inflammatory myofibroblastic tumor in Tianjin Children’s Hospital from2008.1.1to2012.12.31. The tumor mass of this group was almost full removed, and the samples were confirmed by pathology. Summarized clinical manifestation, diagnosis and treatment of IMT, then combined pathologic results to analyses IMT development procedure. Using immunohistochemical technology Envision staining and Dual-color fluorescencein in situ hybridization (FISH) determined of ALK expression in the whole specimens, and analyzed the relationship between clinical expression of ALK positive cells and the tumor local recurrence.Results:1. Clinical manifestation:19patients, male14cases, female5cases; Age from2month to13years, with an average age of5years, median age2.5; Among those lesion,3cases Scalp (1cases with Bone involvement),1cases of neck,2cases of shoulder,2cases of back,1cases of upper arm,2cases of buttock,1cases of thigh,1cases of knee,1cases of abdominal wall,2cases of epididymal,1cases of intestinal wall,1cases of retroperitoneal Involving the stomach wall and Pancreatic and colon. the largest tumor diameter is30x25x15cm3, derived from the retroperitoneal tumor; minimum diameter of0.8x0.8x0.5cm3, derived from the knee.2. Pathological and immunohistochemistry results:ALK was positive in the15cases;Vim was positive in the18cases; SMA was positive in the17cases, Part positive in1cases; desmin was positive in the10cases; S-100was positive in the1cases, Focally positive in2cases; CD68was positive in the6cases, with positive Ki-67>15%in3cases, Ki-67was positive10%in1cases and with positive Ki-67<5%in8cases.3. The results of immunohistochemistry staining:11cases of ALK (+), further detected by FISH, including2cases showed ALK gene rearrangement, clinical data showed local recurrence. Once again resecting the immunohistochemical staining ALK expression is positive too. FISH staining also showed us gene rearrangement. Postoperative chemotherapy, followed up for2years and no recurrence.Conclusion:IMT is a low-grade malignant tumor in Children. Clinical symptoms are not typical. But there are rules to follow, mainly for any part of the body’s mass, mainly in the limbs and trunk, parenchymal organs involved bowel, Tumor has hard texture, clear boundary and no capsule. The final diagnosis depends on pathology, the data showed that, the expression of ALK in tumor tissue has important significance for IMT diagnosis. Operation resection is the only reliable means of treatment, for local recurrence, operation and chemotherapy can obtain good therapeutic effect. The results showed that, ALK gene rearrangement and IMT recurrence is closely related, If FISH suggesting that ALK gene rearrangement, preventive chemotherapy in recurrent cases, get rid of the treatment has been in a passive state.