Characterization of Amyloidosis in the Gastrointestinal Tract With an Emphasis on Histologically Distinct Interstitial Patterns of Deposition and Misinterpretations

Endoscopic and pathological characteristics of gastrointestinal amyloidosis: a retrospective analysis

BACKGROUND

Gastrointestinal amyloidosis (GIA) is a rare manifestation of amyloidosis, characterized by amyloid fibril deposition in the gastrointestinal tract, leading to a range of clinical symptoms. Early diagnosis is challenging due to the nonspecific nature of endoscopic and clinical findings.

OBJECTIVE

To analyze the clinical, endoscopic, and pathological characteristics of GIA and identify potential diagnostic markers for earlier detection.

METHODS

A retrospective study was conducted on 36 patients diagnosed with GIA based on histopathological findings, including Congo Red staining. Clinical, endoscopic, and pathological data were analyzed to identify correlations between lesion morphology, clinical symptoms, and amyloid deposition.

RESULTS

The cohort consisted of 22 males (61.1%) and 14 females (38.9%), with a mean age of 61.7 years. Endoscopic findings were diverse, with elevated lesions (57.1%) most common in the esophagus, stomach, and small intestine, and white patches (66.7%) prevalent in the duodenum. Histopathological analysis confirmed amyloid deposits in 62.8% of biopsy specimens. The small intestine exhibited the highest detection rate (100%), while the colorectum had the lowest (37.5%). Patients with elevated lesions may be asymptomatic, and among those with symptoms, abdominal pain is most common. Flat lesions are primarily associated with multiple symptoms, with abdominal discomfort, pain, distension, and acid reflux being the most frequent. The infiltration depth varied across different gastrointestinal tract segments, with the mucosal layer predominantly affected in the esophagus and stomach, whereas the submucosal layer more significantly involved in the duodenum and colon.

CONCLUSION

Gastrointestinal amyloidosis presents with a wide range of clinical symptoms and endoscopic manifestations. Histopathological diagnosis through standardized biopsy is crucial, and attention should be given to the depth of tissue sampling, as it may play a significant role in reducing misdiagnosis.

Prostatic amyloidosis: pathological features of an underdiagnosed condition

Amyloidosis is a rare disease that can affect genitourinary organs but the involvement of the prostate has been documented in a limited number of cases. We have reviewed morphologic and immunohistochemical features of prostate biopsies or surgical specimens in which an initial diagnosis of amyloidosis was made. Prostatic amyloidosis was diagnosed in 25 patients, 21 of them were needle biopsies (1.16% of these ones). Amyloid was observed inside vessel walls (25 cases) and the stroma (3). No significant differences in the number of affected biopsy samples between patients with and without cardiac amyloidosis were found. In prostatectomies, amyloid was visualized in all the regions of the prostate, being more abundant in the periphery and the posterolateral tissue. Three patients with abundant amyloid in the prostatectomy did not have cardiac amyloidosis. Immunohistochemically prostatic amyloid was positive for transthyretin and P amyloid (24 cases). A amyloid, kappa, and lambda chains were negative. The genetic analysis revealed transthyretin wild-type amyloidosis. Immunohistochemistry was not conclusive in one case of immunoglobulin light chain amyloidosis. In conclusion, prostate amyloidosis is an infrequent finding characterized by the deposition of amyloid inside small vessel walls, and less often in the stroma. It occurs mainly in the periphery of the gland. Amyloid deposits are often subtle and overlooked but relevant as this may be the first sample in which systemic amyloidosis is diagnosed. Immunohistochemistry can be used to subtype amyloid, although there are limitations when confronted with immunoglobulin light chain amyloidosis. Most cases have corresponded to wild-type transthyretin amyloidosis.

Trajectory of brain-derived amyloid beta in Alzheimer's disease: where is it coming from and where is it going?

Alzheimer's disease (AD) is a progressive neurological disorder that primarily impacts cognitive function. Currently there are no disease-modifying treatments to stop or slow its progression. Recent studies have found that several peripheral and systemic abnormalities are associated with AD, and our understanding of how these alterations contribute to AD is becoming more apparent. In this review, we focuse on amyloid‑beta (Aβ), a major hallmark of AD, summarizing recent findings on the source of brain-derived Aβ and discussing where and how the brain-derived Aβ is cleared in vivo. Based on these findings, we propose future strategies for AD prevention and treatment, from a novel perspective on Aβ metabolism.

Clinicopathological Appearance of Epidermal Growth-Factor-Containing Fibulin-like Extracellular Matrix Protein 1 Deposition in the Lower Gastrointestinal Tract: An Autopsy-Based Study

This study examined the patterns of epidermal growth-factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) deposition in the small intestine and colon to evaluate the association between the histopathological severity of EFEMP1 deposition and constipation and determine the colocalization of amyloid transthyretin (ATTR) and EFEMP1 deposits. In 40 older cases (≥80 years of age), EFEMP1 deposition in the small intestine initiated in the submucosal and subserous vessels, subserous interstitium, and serosa (early stage), progressing to the muscularis propria and peri-Auerbach plexus area (intermediate stage), and finally spreading diffusely to other areas, excluding the mucosa and muscularis mucosa (advanced stage). The colon had a similar pattern of progression. During the middle-to-advanced stages, amyloid formation was observed in some vascular and serous deposits. A subgroup of cases was identified in which EFEMP1 deposition was the only presumed cause of constipation. Additionally, we demonstrated the colocalization of ATTR and EFEMP1 deposition. Apple-green birefringence was detected under polarized light only in approximately one-half of the cases in the small intestine and one-third of the cases in the colon. These findings strongly suggest that EFEMP1 deposits are correlated with pathological conditions of the lower gastrointestinal tract. As the histopathological diagnosis using Congo red-stained specimens is challenging, the combined use of elastic fiber staining and EFEMP1 immunohistochemistry is recommended to identify EFEMP1 deposition.

Amyloid-Forming Corpora Amylacea and Spheroid-Type Amyloid Deposition: Comprehensive Analysis Using Immunohistochemistry, Proteomics, and a Literature Review

This study aimed to elucidate the similarities and differences between amyloid-forming corpora amylacea (CA) in the prostate and lung, examine the nature of CAs in cystic tumors of the atrioventricular node (CTAVN), and clarify the distinctions between amyloid-forming CA and spheroid-type amyloid deposition. We conducted proteomics analyses using liquid chromatography-tandem mass spectrometry with laser microdissection and immunohistochemistry to validate the characteristics of CAs in the lung and prostate. Our findings revealed that the CAs in these organs primarily consisted of common proteins (β2-microglobulin and lysozyme) and locally produced proteins. Moreover, we observed a discrepancy between the histopathological and proteomic analysis results in CTAVN-associated CAs. In addition, while the histopathological appearance of the amyloid-forming CAs and spheroid-type amyloid deposits were nearly identical, the latter deposition lacked β2-microglobulin and lysozyme and exhibited evident destruction of the surrounding tissue. A literature review further supported these findings. These results suggest that amyloid-forming CAs in the lung and prostate are formed through a shared mechanism, serving as waste containers (wasteosomes) and/or storage for excess proteins (functional amyloids). In contrast, we hypothesize that while amyloid-forming CA and spheroid-type amyloid deposits are formed, in part, through common mechanisms, the latter are pathological.