Corpora amylacea in benign prostatic acini are associated with concurrent, predominantly low-grade cancer

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.

From corpora amylacea to wasteosomes: History and perspectives

Corpora amylacea (CA) have been described in several human organs and have been associated with ageing and several pathological conditions. Although they were first discovered two centuries ago, their function and significance have not yet been identified. Here, we provide a chronological summary of the findings on CA in various organs and identify their similarities. After collecting and integrating these findings, we propose to consider CA as waste containers created by specific cells, which sequester waste products and foreign products, and assemble them within a glycan structure. The containers are then secreted into the external medium or interstitial spaces, in this latter case subsequently being phagocytosed by macrophages. This proposal explains, among others, why CA are so varied in content, why only some of them contain fibrillary amyloid proteins, why all of them contain glycan structures, why some of them contain neo-epitopes and are phagocytosed, and why they can be intracellular or extracellular structures. Lastly, in order to avoid the ambiguity of the term amyloid (which can indicate starch-like structures but also insoluble fibrillary proteins), we propose renaming CA as "wasteosomes", emphasising the waste products they entrap rather than their misleading amyloid properties.

Presence of corpora amylacea among prostate cancer cells: an unrecognised feature of intraductal carcinoma of the prostate

Corpora amylacea (CA) is usually present in benign prostatic ducts and acini, and its presence is considered suggestive of negative or low-risk prostate cancer. The clinicopathological definition of CA among prostate cancer cells (CAPCCs)-described as CA entirely surrounded by invasive cancer cells-has not been discussed. As intraductal carcinoma of the prostate (IDC-P) is a well-known adverse prognostic factor in prostate cancer, this study aimed to elucidate the relationship between CAPCC and IDC-P. We enrolled 366 patients who underwent robotic-assisted radical prostatectomies between 2012 and 2018 at Aichi Medical University Hospital. All surgical specimens were independently reviewed by two genitourinary pathologists. The median age of the patients was 68.5 years; the median serum prostate-specific antigen was 6.49 ng/mL. IDC-P was observed in 143 (39.1%) patients, while the presence of CAPCC was observed in 47 cases (12.8%). Patients with CAPCC were associated with more advanced clinical and pathological T stages, as well as Gleason scores, than those without CAPCC (p=0.018, p<0.001, p=0.036). Notably, the presence of CAPCC was significantly associated with the presence of IDC-P (39 cases) and a high Gleason score compared with the absence of CAPCC (12 cases) (p<0.001 and p=0.036, respectively). The presence of CAPCC is an adverse pathological feature, often closely related to IDC-P. Therefore, CAPCC may be a surrogate finding to detect IDC-P via haematoxylin and eosin staining.

The Etiology and Pathophysiology Genesis of Benign Prostatic Hyperplasia and Prostate Cancer: A New Perspective

Background: The etiology of benign prostatic hyperplasia and prostate cancer are unknown, with ageing being the greatness risk factor. Methods: This new perspective evaluates the available interdisciplinary evidence regarding prostate ageing in terms of the cell biology of regulation and homeostasis, which could explain the timeline of evolutionary cancer biology as degenerative, inflammatory and neoplasm progressions in these multifactorial and heterogeneous prostatic diseases. Results: This prostate ageing degeneration hypothesis encompasses the testosterone-vascular-inflamm-ageing triad, along with the cell biology regulation of amyloidosis and autophagy within an evolutionary tumorigenesis microenvironment. Conclusions: An understanding of these biological processes of prostate ageing can provide potential strategies for early prevention and could contribute to maintaining quality of life for the ageing individual along with substantial medical cost savings.