Localized amyloidosis: A diagnostic pitfall in breast pathology

Area of Science:

• Pathology
• Oncology
• Radiology

Background:

• Amyloidosis involves extracellular protein fibril deposition in a beta-pleated sheet configuration.
• Breast amyloidosis is rare, often localized, and can be a late sign of systemic disease.
• Clinicopathologic features of localized breast amyloidosis are not well-described.

Purpose of the Study:

• To describe the clinicopathologic features of localized breast amyloidosis.
• To highlight the importance of recognizing breast amyloidosis in differential diagnosis.
• To evaluate the association with underlying conditions and systemic disease.

Main Methods:

• Retrospective review of 10 cases of breast amyloidosis diagnosed at an institution.
• Analysis of patient demographics, clinical presentation, mammographic findings, and biopsy results.
• Amyloid typing using Congo red staining and specific typing methods.

Main Results:

• Ten female patients (mean age 69) diagnosed with breast amyloidosis.
• Presentations included mammographic calcifications, masses, and axillary lymphadenopathy.
• Amyloid types identified: light chain lambda, transthyretin, light chain kappa, and insulin-derived.
• Amyloid found with benign and neoplastic breast tissue, and in axillary lymph nodes.
• Associated conditions: autoimmune disease, B cell lymphomas, and diabetes mellitus.
• No patients showed clinical evidence of systemic amyloidosis.

Conclusions:

• Breast amyloidosis is an important differential diagnosis for breast and axillary abnormalities on mammography.
• Accurate biopsy diagnosis prevents unnecessary interventions and guides further work-up.
• Awareness of clinicopathologic features is vital for pathologists reviewing breast biopsies.