Incidentally Detected Amyloid Light-Chain Amyloidosis Caused by Monoclonal Gammopathy of Undetermined Significance: Possible Time-Dependent Change in Colonic Findings

Using machine learning approaches to develop a fast and easy-to-perform diagnostic tool for patients with light chain amyloidosis: a retrospective real-world study

Immunoglobulin light chain (AL) amyloidosis is a severe disorder caused by the accumulation of amyloid fibrils, leading to organ failure. Early diagnosis is crucial to prevent irreversible damage, yet it remains a challenge due to nonspecific symptoms that often appear later in the disease progression. A retrospective study analyzed data collected from 133 AL amyloidosis patients and 271 non-AL patients with similar symptoms but different diagnoses between January 1st, 2017, and September 30th, 2022. Demographic data and laboratory test results were collected. Subsequently, significant features were identified by both logistic regression and independent expert clinical ability. Eventually, logistic regression and four machine learning (ML) algorithms were employed to construct a diagnostic model, utilizing fivefold cross-validation and blind set testing to identify the optimal model. The study successfully identified nine independent predictors of AL amyloidosis patients with kidney or cardiac involvement, respectively. Two models were developed to identify key features that distinguish AL amyloidosis from nephrotic syndrome and hypertrophic cardiomyopathy, respectively. The light gradient boosting machine (LightGBM) model emerged as the most effective, demonstrating superior performance with the area under curve (AUC) of 0.90 in both models, alongside high sensitivity, specificity, and F1-score. This research highlights the potential of using a machine learning-based LightGBM model to facilitate early and accurate diagnosis of AL amyloidosis. The model's effectiveness suggests it could be a valuable tool in clinical settings, aiding in the timely identification of AL amyloidosis among patients with non-specific symptoms. Further validation in diverse populations is recommended to establish its universal applicability.

Monoclonal Gammopathy of Multisystemic Significance: A Challenging Diagnosis of Light Chain Amyloidosis

We present a case of a 51-year-old woman diagnosed with light chain amyloidosis associated with monoclonal gammopathy of undetermined significance (MGUS). Initially, she presented with symptoms of heart failure, including palpitations, chest tightness, and shortness of breath, which were attributed to myocarditis based on cardiac magnetic resonance (CMR) imaging findings. However, her condition rapidly deteriorated, with recurrent admissions for worsening heart failure, cardiogenic shock, and stroke. A cardiac biopsy ultimately confirmed light chain amyloidosis, a rare complication of MGUS, which has a long-term risk of 0.8% in patients with light chain MGUS. Despite aggressive treatment, including chemotherapy and biventricular assist device implantation, her condition continued to decline, and she became ventilator-dependent and subsequently passed away. This case highlights the importance of considering amyloidosis in patients with MGUS and underscores the need for early diagnosis and intervention to prevent catastrophic outcomes.

Systemic AL amyloidosis with multiple submucosal hematomas of the colon: a case report and literature review

Amyloid light-chain (AL) amyloidosis rarely causes colorectal submucosal hematoma. A 76-year-old man presented with a complaint of bloody stool. An initial colonoscopy revealed ulcerative lesions in the descending colon, leading to a diagnosis of ischemic colitis. One month later, he presented with cardiac failure, suspected cardiac amyloidosis, and underwent a second colonoscopy. Although it revealed multiple ulcerative lesions from the ascending to transverse colon, biopsy samples did not confirm amyloid deposition. He underwent a third colonoscopy 3 weeks later due to recurrent bloody stool. It showed multiple submucosal hematomas from the ascending to descending colon concomitant with ulcerative lesions in the descending colon and multiple elevated lesions in the sigmoid colon. Biopsy samples confirmed amyloid deposition. Using a systemic search, multiple myeloma with AL amyloidosis was diagnosed. Colorectal submucosal or intramural hematomas are conditions usually encountered in trauma, antithrombotic use, or coagulation disorders. Based on our review of the literatures, we identified several differences between colorectal intramural hematoma caused by amyloidosis and those caused by other etiologies. We believe that amyloidosis should be considered when relatively small and multiple colorectal hematomas, not restricted to the sigmoid colon, and with concomitant findings of erosions and ulcers, are observed.

A Rare Case of Gastrointestinal Amyloidosis Due to Monoclonal Gammopathy of Undetermined Significance

Amyloidosis of the gastrointestinal (GI) tract is caused by the deposition of fibrils made of serum proteins into extracellular spaces. It is an uncommon disease with a poor prognosis, requiring prompt diagnosis and treatment. Treatment for amyloid light chain (AL)-type amyloidosis involves supportive care as well as addressing any underlying plasma cell dyscrasias. We present the case of a 64-year-old female diagnosed with AL-type GI amyloidosis with associated monoclonal gammopathy of undetermined significance. Unfortunately, the treatment was initiated nine months after the initial presentation, and she died one month later. Awareness of GI amyloidosis may allow for faster diagnosis and treatment in future patients.

A Case of Systemic AL Amyloidosis Diagnosed by Screening Colonoscopy

Amyloidosis encompasses several diseases associated with deposition of low-molecular-weight proteins in an abnormal configuration. In light-chain amyloidosis (AL), monoclonal free lambda (λ) or kappa (κ) light chains are the amyloid proteins involved and can deposit in almost any organ. Symptoms vary depending on presence and extent of organ involvement, and thus, clinical presentation varies. Diagnosis requires biopsy of the affected tissue, and sometimes, fat pad or bone marrow biopsy is completed initially. Prognosis of AL amyloidosis depends on the presence of cardiac involvement. Treatment of AL amyloidosis involves systemic chemotherapy and evaluation for autologous stem cell transplant. Herein, we present a case report of an asymptomatic middle-aged female who was diagnosed with AL amyloidosis during an average-risk screening colonoscopy, which is an unusual setting. We discuss the workup involved, clinical presentation, and gastroenterology-related organ involvement.

Systemic Immunoglobulin Light Chain Amyloidosis Involving the Large Intestine

Amyloidosis is characterized by extracellular tissue deposition of fibrils resulting in disruption of tissue structure and function. Gastrointestinal amyloidosis commonly results from chronic inflammatory disorders (amyloid A amyloidosis) and is less commonly seen in immunoglobulin light chain amyloidosis. We present a rare case of a 50-year-old man with a history of immunoglobulin light chain amyloidosis who presented with abdominal pain, blood in stool, diarrhea, and weight loss. Colonoscopy and biopsies revealed amyloid deposits in the colon. The patient subsequently was referred to colorectal surgery for evaluation of total colectomy with further plans for chemotherapy and subsequent hematopoietic cell transplantation.

Primary Localized Amyloidosis of the Intestine: A Pathologist Viewpoint

Background

Localized amyloidosis of the intestine is a rare entity, which can clinically masquerade several conditions such as colitis, polyps, and malignant tumors. This study aims to evaluate the clinicopathological features of this entity.

Methods

To evaluate the clinicopathological features of this entity, a comprehensive search of the literature (1960 to 2019) was done using the following keywords: "amyloidosis" and "small intestine" or "duodenum" or "ileum" or "jejunum" or "colon". We identified 756 studies about gastrointestinal amyloidosis. Data were examined for 27 studies about localized intestinal amyloidosis. The clinicopathological features were described.

Results

The age at presentation ranged from 29 to 88 years. The male to female ratio was 3:1. The jejunum and sigmoid colon were the most commonly involved sites. Abdominal pain and intestinal obstruction (small intestine), or rectal bleeding (sigmoid region) were the most common clinical presentations. Colonoscopic findings included wall thickening, mucosal ulcerations (small intestine), and tumor-like masses (colon).

Conclusions

The clinical presentations of localized intestinal amyloidosis depend on the site of the deposition of the amyloid. In most cases, amyloid deposits consisted of light chain protein.