Gastric and cardiac inflammatory myofibroblastic tumor: an extremely rare case

Background: Inflammatory myofibroblastic tumor (IMT) is a unique, rarely metastatic tumor composed of myofibroblasts and fibrous spindle cells with inflammatory cell infiltration that can affect any organ in the human body. By reviewing the relevant literature on PubMed, we found that this is the first case report of IMT with both gastric and cardiac involvement.

Case presentation: A 57-year-old male patient was admitted to the hospital with complaints of malaise, poor appetite, and epigastric pain with black stools. We found a mass in the patient's stomach and left atrium by contrast-enhanced computed tomography, 18 F-fluorodeoxyglucose positron emission tomography/computed tomography, and other tests. The patient underwent laparoscopic Billroth II subtotal gastrectomy and Braun's gastrointestinal reconstruction under general anesthesia. On the 46th day following stomach surgery, the cardiac tumor was removed under general anesthesia. The patient has treated with doxorubicin 70 mg of D1 chemotherapy two months after cardiac surgery. Postoperative pathological immunohistochemistry of the mass confirmed the diagnosis of an IMT. His review three months after the cardiac surgery suggested the progression of the left atrial mass, but he declined further treatment and finally died one month after the review.

Conclusions: As a unique class of tumors that rarely metastasize, IMTs have an unknown etiology and pathogenesis, and distant metastasis is primarily observed in patients with negative activin receptor-like kinase (ALK) expression. The preferred treatment for IMT is complete surgical resection, and the effectiveness of adjuvant therapy for patients with distant metastases is still being determined. The clinical presentation of IMT lacks specificity and is often related to the location of tumor growth, which poses a diagnostic challenge. Pathological immunohistochemistry is the only way to confirm the diagnosis at present. Our case report reminds clinicians that a category of ALK-negative IMT with a tendency toward distant metastasis should not be ignored.