Amyloidosis Organ-Specific Manifestations

Amyloidosis Organ-Specific Manifestations

• Heart: Systemic AL amyloidosis causes high mortality (ATTR better prognosis). Presents as restrictive cardiomyopathy, possibly with pericardial effusion. MRI shows diffuse myocardial thickening, affecting all heart chambers, with subendocardial/transmural late gadolinium enhancement (LGE).

• Larynx, Trachea, Bronchi: Usually localized amyloidosis. Symptoms include airway thickening, multifocal plaques/masses (sometimes calcified).

• Lung Parenchyma: Localized form shows nodules (amyloidomas), often calcified. Systemic AL/AA amyloidosis involves interlobular septal thickening, reticulation, micronodules, consolidation, and punctate calcification, mostly in the base and periphery, with pleura involvement possible. AA amyloidosis may coexist with lymphangioleiomyomatosis (LIP).

• Mediastinum: Typically systemic amyloidosis, characterized by lymphadenopathy (possibly calcified) or a focal mass.

• GI Tract: Very common in systemic amyloidosis. Presents with dysmotility, bleeding, diarrhea, obstruction, or perforation. Most common involvement is in the duodenum then stomach. CT may show luminal dilation, diffuse/nodular wall thickening, and calcification. Focal amyloidomas are rare.

• Liver and Spleen: Common in systemic amyloidosis, causing diffuse organomegaly and possible punctate calcifications. Liver may be hypoattenuating on unenhanced CT; spleen shows reduced arterial enhancement. Gallbladder wall thickening is possible. Rare focal amyloidomas.

• Pancreas: Usually localized amyloidosis, leading to Type 2 diabetes. Diffuse infiltration and enlargement of the pancreas are common, with loss of T1 hyperintensity on MRI, and possible punctate calcification mimicking chronic pancreatitis.

• Renal Parenchyma: Frequent in systemic amyloidosis, causing nephrotic syndrome and renal failure. Kidneys may be enlarged and echogenic in early disease, with focal masses. Atrophy and amorphous calcification are seen in chronic disease. Renal sinus fat infiltration may occur.

• Urothelium: Localized, most commonly affecting bladder>ureter>renal pelvis>urethra. Focal thickening, stricture, or mass (possibly calcified). Isolated involvement of the seminal vesicles is also possible, presenting with diffuse wall thickening.

• Adrenals and Testes: Systemic amyloidosis. Characterized by diffuse infiltration and enlargement, leading to potential organ dysfunction.

• Mesentery and Retroperitoneum: Systemic amyloidosis. Infiltrative soft-tissue replacement of normal fat, often with progressive calcification. Low-attenuation lymphadenopathy may also be present; ascites is rare.

• Joints (Amyloid Arthropathy): Typically in Aβ2M amyloidosis. Bilateral erosive polyarthropathy affecting wrists, shoulders, hips, and knees. MRI shows T1/T2 hypointense synovial thickening (no blooming, differentiating from pigmented villonodular synovitis—PVNS) along with effusions, and without joint space narrowing. Surrounding muscle swelling (shoulder pad sign) may be present. Cervical spine involvement is common.

• Bones and Soft Tissues: Mostly systemic AL amyloidosis. Focal soft-tissue masses are common; osseous lesions are lytic. Muscle involvement can mimic pseudohypertrophy or inflammatory myopathy. Breast involvement can resemble carcinoma.

• Peripheral Nerves: Often in mutant ATTR or AL amyloidosis, marked by diffuse nerve enlargement, with potential enhancement on MRI. Isolated carpal tunnel syndrome is possible in wild-type ATTR or Aβ2M amyloidosis.

• Central Nervous System (CNS):

• Alzheimer's Disease: Most common localized Aβ amyloidosis form. Associated with cerebral atrophy, especially in the parietal and mesial temporal lobes.

• Cerebral Amyloid Angiopathy: Common, causing numerous microhemorrhages in subcortical areas. Larger hemorrhages (intracerebral/subarachnoid) or focal inflammation (vasogenic edema) may occur.

• Cerebral Amyloidoma: Rare, characterized by enhancing nodular masses with surrounding vasogenic edema.

• Pituitary: Amyloid deposits can be seen in pituitary adenomas.

• Head and Neck:

• Orbits: Localized disease affecting lacrimal glands and other orbital structures.

• Nasal Cavity/Paranasal Sinuses: Localized disease involving a focal mass, potentially obstructing drainage.

• Oral Cavity: Systemic disease. Macroglossia is a hallmark.

• Thyroid and Salivary Glands: Systemic disease; may cause organ dysfunction.

Explore the role of amyloidosis in various organs, including the heart, lungs, and GI tract. Understand the specific symptoms and diagnostic techniques associated with systemic and localized forms. This quiz provides insights into the clinical implications and outcomes of amyloidosis manifestations.