Gastrointestinal stromal tumor(GIST)is a rare but an important clinical entity seen in our clinical practice.It is the most common mesenchymal tumor of the gastrointestinal tract and most common malignancy of the smal...Gastrointestinal stromal tumor(GIST)is a rare but an important clinical entity seen in our clinical practice.It is the most common mesenchymal tumor of the gastrointestinal tract and most common malignancy of the small intestine.Although the exact prevalence of GIST is not known,the incidence of GIST has been increasing.GISTs arise from interstitial cells of Cajal.Most of the GISTs occur due to mutation in c-kit gene or platelet derived growth factor receptor alpha gene.15%of GISTs do not have these mutations and they are called wildtype GISTs.Almost all GISTs express KIT receptor tyrosine kinase.Histologically,GISTs look like spindle cell tumors most of the time but they can be epitheloid or mixed type.The median size of GISTs varies from 2.7 cm to 8.9 cm.Clinically,patients with small GISTs remain asymptomatic but as the GIST size increases,patients present with various symptoms depending on the location of the GIST.Most of GISTs are located in the stomach or small bowel.Diagnosis is suspected on imaging and endoscopic studies,and confirmed by tissue acquisition with immunohistochemical staining.The aggressiveness of GISTs depends on the size,mitotic index and location.Surgical resection is the treatment of choice.But various endoscopic modalities of resection are increasingly being tried.Tyrosine kinase inhibitors are extremely useful in the management of large GISTs,unresectable GISTs and metastatic GISTs.Treatment options for metastatic GISTs also include radiotherapy,chemotherapy,hepatic artery embolization,chemoembolization and radiofrequency ablation.展开更多
Inflammatory myofibroblastic tumor(IMT)of the biliary tract is rare,and often difficult to diagnose or to distinguish from other tumors due to its atypical clinical presentation and nonspecific radiological features.H...Inflammatory myofibroblastic tumor(IMT)of the biliary tract is rare,and often difficult to diagnose or to distinguish from other tumors due to its atypical clinical presentation and nonspecific radiological features.Histologically,IMTs are(myo)fibroblastic neoplasms with a prominent inflammatory infiltrate.They are characterized by receptor tyrosine kinase gene rearrangements,most often involving an anaplastic lymphoma kinase(ALK)translocation.The final diagnosis of IMT depends on histopathology and immunohistochemical examination.In this manuscript,we provide a clinical and morphomolecular overview of IMT and the difficulties that may arise in using immunohistochemical and molecular techniques in diagnosing IMT.展开更多
文摘Gastrointestinal stromal tumor(GIST)is a rare but an important clinical entity seen in our clinical practice.It is the most common mesenchymal tumor of the gastrointestinal tract and most common malignancy of the small intestine.Although the exact prevalence of GIST is not known,the incidence of GIST has been increasing.GISTs arise from interstitial cells of Cajal.Most of the GISTs occur due to mutation in c-kit gene or platelet derived growth factor receptor alpha gene.15%of GISTs do not have these mutations and they are called wildtype GISTs.Almost all GISTs express KIT receptor tyrosine kinase.Histologically,GISTs look like spindle cell tumors most of the time but they can be epitheloid or mixed type.The median size of GISTs varies from 2.7 cm to 8.9 cm.Clinically,patients with small GISTs remain asymptomatic but as the GIST size increases,patients present with various symptoms depending on the location of the GIST.Most of GISTs are located in the stomach or small bowel.Diagnosis is suspected on imaging and endoscopic studies,and confirmed by tissue acquisition with immunohistochemical staining.The aggressiveness of GISTs depends on the size,mitotic index and location.Surgical resection is the treatment of choice.But various endoscopic modalities of resection are increasingly being tried.Tyrosine kinase inhibitors are extremely useful in the management of large GISTs,unresectable GISTs and metastatic GISTs.Treatment options for metastatic GISTs also include radiotherapy,chemotherapy,hepatic artery embolization,chemoembolization and radiofrequency ablation.
文摘Inflammatory myofibroblastic tumor(IMT)of the biliary tract is rare,and often difficult to diagnose or to distinguish from other tumors due to its atypical clinical presentation and nonspecific radiological features.Histologically,IMTs are(myo)fibroblastic neoplasms with a prominent inflammatory infiltrate.They are characterized by receptor tyrosine kinase gene rearrangements,most often involving an anaplastic lymphoma kinase(ALK)translocation.The final diagnosis of IMT depends on histopathology and immunohistochemical examination.In this manuscript,we provide a clinical and morphomolecular overview of IMT and the difficulties that may arise in using immunohistochemical and molecular techniques in diagnosing IMT.
