IPT or has been known as term IMT (inflammatory myofibroblastic tumor) are pseudo-sarcomatous lesions of the viscera and soft tissues which often occur in children and young adults, however, IMTs have the greater proliferation of myofbroblastic cells than IPTs, which represent more of inflammatory cells than IMTs [11, 14]. IPT in the esophagus is an extremely rare lesion and develops from the submucosa. Several reports suggest that esophageal IPT often has superficial mucosal ulcers [10]. Our case did not show mucosal ulceration on endoscopy. So far, the etiology and pathogenesis of IPT is not clear, it can be seen that some cases are related to Ebtein-barr virus, mycobacterium, immune-autoimmune condition, trauma, inflammation caused by surgery or patients with an abnormality in wound healing [5, 11, 15]. In our patient's case, the disease progressed slowly and gradually, and no relevant cause was found. The characteristics in radiologic investigations of IPT are nonspecific, possibly because of the variable amount inflammation cellular infiltration and strong fibrous proliferation. On computed tomography, IPT is usually a pre-injection hypoattenuating lesion and a heterogeneous strong enhancement after injection, with calcified lesions in the tumor, which was found these features in our patient's case [11, 16].
Depending on the location, size, and clinical presentation, esophageal IPT can be treated with endoscopic gastroesophageal resection, surgical excision, tumor resection, or esophagectomy [8, 16]. The choice of surgical excision or esophagectomy must be based on a comprehensive assessment and carefully considering radical resection ability, the recurrence risk and surgical complications. The method of local excision is usually performed in cases where the tumor is smaller than 2.5 cm and there is no evidence of tumor invasion of the muscle layer on endoscopic ultrasound, otherwise, esophagectomy is usually performed in cases of the tumor larger than 2.5 cm, or the tumor caused esophageal obstruction, or there is evidence of tumor invasion of the esophageal muscle layer [17]. With such treatment, the local recurrence rate is less than 10% [18]. In our case, the patient showed signs of choking, could only drink water, showed esophageal obstruction, 10 kg weight loss, on computed tomography of the esophagus there was a very large tumor, occupying most of the thoracic esophagus, so that we decided performing esophagectomy to completely removal the tumor.
Histopathologically, IPT contains acute and chronic inflammatory cells including lymphocytes, plasma cells, rhabdoid fibroblasts, and collagen (inflammatory response) [4, 11]. Several cases of IPT have been found IgG4 positive plasma cells which be associated with sclerosing disease, a systemic disease in which extensive infiltration of plasma cells, T cells, and various tissues is positive for IgG4 [11]. This condition manifests in autoimmune pancreatitis, sclerosing cholangitis, salivary gland inflammation, retroperitoneal fibrosis, tubulointerstitial nephritis, and interstitial pneumonia [19]. IgG4-associated IPT has been found in both patients with and without autoimmune pancreatitis, and in these case, systemic corticosteroids therapy was considered, especially in cases of incomplete resection [20, 21]. Our patient showed an increased number of IgG4-positive plasma cells (the number is about 120 IgG4(+) plasma cells per one HPF with original magnification x 400). IPT is distinguishable from lymphoma because IPT has both B and T cells, whereas lymphoma usually has only T cells or B cells [12]. In our case, the tumor was completely removed by esophagectomy and the symptoms totally disappear in long-term follow-up, so that systemic corticosteroids therapy was not considered.
Conclusion
Inflammatory pseudotumor of the esophagus is a very rare benign lesions that be difficult to make a definitive diagnosis preoperatively but could led to aggressive clinical presentation. The gold standard of IPT diagnosis is histopathological examination of surgically removed specimens. Radical resection is still the most efficient treatment method, while systemic corticosteroids therapy was considered in case of immune-relation and incomplete resection.