Amyloidosis
Jesse K. McKenney, MD
Key Facts
Terminology
Deposition of amyloid protein in urinary bladder
2 types
Primary localized process
Systemic amyloidosis
Microscopic Pathology
Deposition of eosinophilic amorphous material in lamina propria and superficial muscularis propria
Ancillary Tests
“Apple green” birefringence on Congo red under polarized light
Thioflavin T fluorescence is seen
Randomly arranged, rigid, nonbranching, 8-10 nm fibrils by electron microscopy
Top Differential Diagnoses
Fibrosis
 Partial cystectomy shows “tumor” forming amyloidosis (amyloidoma). Large lesions may ulcerate the overlying mucosa due to a large submucosal and mural mass. |
 Dense homogeneous eosinophilic material is characteristic of amyloid. In the localized form, the amyloid entraps blood vessels  but is not typically confined to the vascular walls. |
TERMINOLOGY
Synonyms
Amyloid tumor (if localized)
Definitions
Deposition of amyloid protein in urinary bladder
2 types
Primary localized process
Systemic amyloidosis
ETIOLOGY/PATHOGENESIS
Systemic
Primary
AL-type amyloid
Secondary
Associated with chronic inflammatory conditions
Autoimmune causes, such as rheumatoid arthritis and ankylosing spondylitis
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
