Abstract
BackgroundInflammatory myofibroblastic tumor (IMT) of the stomach is extremely rare in adults and exhibits a variable biological behavior that ranges from frequently benign lesions to more aggressive variants. Here we report a case of gastric IMT with lymph node metastasis in an adult who had undergone total colectomy for familial adenomatous polyposis (FAP).Case presentationA 37-year-old man presented gradual-onset epigastric discomfort; he had undergone total colectomy for FAP 6 years before. The upper endoscopy revealed diffuse polyposis in the body of stomach and a submucosal protruding tumor of approximately 4.5 × 3.5 cm in the gastric angular incisure, appearing like gastrointestinal stromal tumor. Histology after surgery verified the diagnosis of fundic gland polyposis (FGPs) and gastric IMT with lymph node metastasis. Both the primary IMT tissue and its metastatic lesion but not the FGP or FAP tissue were positive for anaplastic lymphoma kinase (ALK) on immunohistochemical staining. Fluorescent in situ hybridization confirmed the existence of ALK rearrangement in IMT tissues. However, the patient exhibited no abnormalities in microsatellite instability or mismatch repair-system components, including MSH6, MSH2, MLH1 and PMS2, in IMT, FGP or FAP tissue.ConclusionsThis case allowed for exploring the relationship among IMT, FGP and FAP and indicates that gastric IMT should be considered in the diagnosis of a gastric mass in patients with FAP. ALK may be a useful biomarker in the diagnosis of IMT and its metastatic lesions.
Highlights
Inflammatory myofibroblastic tumor (IMT) of the stomach is extremely rare in adults and exhibits a variable biological behavior that ranges from frequently benign lesions to more aggressive variants
This case allowed for exploring the relationship among IMT, fundic gland polyposis (FGPs) and familial adenomatous polyposis (FAP) and indicates that gastric IMT should be considered in the diagnosis of a gastric mass in patients with FAP
anaplastic lymphoma kinase (ALK) may be a useful biomarker in the diagnosis of IMT and its metastatic lesions
Summary
We describe the first case of ALK-positive gastric IMT with metastasis in an adult after total colectomy for FAP. Awareness of the inflammatory component and ALK rearrangement is important to distinguish IMT from other submucosal lesions. Detecting ALK-positive tumor cells in lymph nodes is a reliable way to verify IMT metastasis. Further investigations are required to clarify possible a genetic basis for concurrence of IMT and FAP. Immunohistochemistry of protein expression of immunoglobulin G (IgG) and IgG4 in lymphocytes of gastric IMT.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have