Localized light chain amyloidosis is considered to be a plasmacytic B-cell lymphoproliferative disorder caused by antigenic induction. A hypothesis has been proposed that antigen-induced local plasmacytic B cells produce amyloidogenic proteins that are processed into amyloid fibrils in giant cells leading to amyloid fibril deposition. However, the inciting antigen exposure or immune response that signals plasmacytic B-cell infiltration, activation, and selection, is unknown. A case of localized light chain amyloidosis of the stomach that gradually regressed endoscopically after Helicobacter pylori eradication is presented. Histologically, plasmacytes decreased markedly and macrophages disappeared after eradication, and they are thought to play important roles in amyloid formation. There have been no reports of localized gastric amyloidosis in which the lesion regressed and few reports showing the relationship between localized gastric amyloidosis and Helicobacter pylori infection that evaluated the changes after eradication. Given the review of the latest findings about localized light chain amyloidosis, in addition to circumstantial evidence from the clinical course of this case, we would like to propose a bold new hypothesis that Helicobacter pylori could be one of the antigens inducing localized light chain amyloidosis of the stomach.

Localized gastrointestinal tract amyloidosis is uncommon and little is known regarding this entity. There is no current standard of care for the management of localized amyloidosis. The objective of this study was to evaluate the characteristics, available treatments, outcomes and surveillance of these patients.

We conducted a systematic review of cases reported in the literature from 1962 to 2021. Patients with gastrointestinal amyloidosis reported in English literature were included in the analysis. We described and summarized the patient's characteristics, treatments, clinical presentations, outcomes and surveillance.

The systematic review of reported clinical cases included 62 patients. In these patients, the most common site of amyloid deposition was the stomach (42%). The median age of diagnosis is 64.4 years old; there is a 2:1 prevalence among males (63%) to females (37%); abdominal pain is the most common type of presentation (41%), although patients could also be asymptomatic. There is a high curative rate (100%) with resection alone. Among patients treated with a type of systemic therapy, 80% achieved a complete response. The minority of cases reported a type of surveillance post treatment, and among those 62% pursued serial clinical evaluations alone.

To our knowledge, this is the first and largest systematic review of the literature in gastrointestinal tract amyloidosis. This is more common among males and seems to have an excellent curative rate (100%) with surgery alone. Systemic therapy is an option for those with non-resectable amyloidomas. Serial clinical evaluations should be part of the standard surveillance care in these patients.

We report the case of a 38-year-old female with gastrointestinal amyloidosis who presented with acute abdominal pain. The computed tomography scan showed that the patient had generalized lymphadenopathy. This clinical picture with absolute leukocytosis was interpreted as an acute secondary bacterial process of unspecified etiology with generalized lymphadenopathy. The patient was administered a broad-spectrum antibacterial drug and detoxication therapy. The upper endoscopy revealed bleeding of unknown origin. After a 2-day conservative hemostatic therapy, gastric tumor involvement was suggested during control endoscopy. The human immunodeficiency virus (HIV) antibodies were found with the following confirmation of their specificity by immunoblotting. Histopathological study of the biopsy specimens made it possible to diagnose gastrointestinal AA/AL-amyloidosis complicated by gastrointestinal bleeding.

Localized gastric amyloidosis (LGA) is a rare disease characterized by abnormal extracellular deposition of amyloid protein restricted to the stomach and it is confirmed by positive results of Congo red staining. Over decades, only a few cases have been reported and studies or research focusing on it are few. Although LGA has a low incidence, patients may suffer a lot from it and require proper diagnosis and management. However, the pathology of LGA remains unknown and no overall review of LGA from its presentations to its prognosis has been published. Patients with LGA are often asymptomatic or manifest atypical symptoms, making it difficult to differentiate from other gastrointestinal diseases. Here, we report the case of a 70-year-old woman with LGA and provide an overview of case reports of LGA available to us. Based on that, we conclude current concepts of clinical manifestations, diagnosis, treatment, and prognosis of LGA, aiming at providing a detailed diagnostic procedure for clinicians and promoting the guidelines of LGA. In addition, a few advanced technologies applied in amyloidosis are also discussed in this review, aiming at providing clinicians with a reference of diagnostic process. With this review, we hope to raise awareness of LGA among the public and clinicians.

We herein report an extremely rare case of localized gastric amyloidosis (LGA) with morphological changes during the follow-up. A 71-year-old woman who had a depressed lesion with central elevation in the gastric lower body was diagnosed with LGA. Esophagogastroduodenoscopy at 10 years after the initial examination showed that the lesion had grown and changed morphologically, exhibiting a submucosal tumor-like appearance. Since the lesion was confined to the submucosa, the patient underwent endoscopic submucosal dissection. The final pathological diagnosis was amyloid light-chain (AL)-type LGA. This case may provide useful information regarding the natural history of AL-type LGA.

Localized primary gastric amyloidosis is a rare disorder characterized by the extracellular deposition of insoluble fibrillary protein in the stomach and can mimic various diseases on endoscopic examination, including gastrointestinal stromal tumors, gastric cancer and ulcers.

Here, we report a series of three cases of localized gastric amyloidosis mimicking gastric mucosa-associated lymphoid tissue (MALT) lymphoma on endoscopic examination that were evaluated over the past ten years in our hospital. The different detection times of this rare disease resulted in three completely different outcomes, indicating the strong importance of early detection, diagnosis and treatment. The difficulties encountered in making an accurate diagnosis and differential diagnosis are highlighted, and this report provides clinical experience for the diagnosis of localized primary gastric amyloidosis.

Localized gastric amyloidosis is a rare metabolic disease that resembles MALT lymphoma. Early detection, diagnosis and treatment of localized gastric amyloidosis result in an excellent prognosis.