Primary Systemic Amyloidosis Characterized by Multiple Keratinous Cysts: A Case Report

Area of Science:

• Nephrology
• Hematology
• Dermatology

Background:

• Primary systemic amyloidosis is a rare plasma cell disorder.
• It involves the deposition of immunoglobulin light chains, leading to organ damage.
• Co-occurrence with multiple myeloma is documented but requires careful diagnosis.

Observation:

• A 67-year-old male presented with orbital plaques, ecchymosis, and nail dystrophy.
• Serum lambda light chain was positive.
• Histopathology revealed keratinous cysts and Congo red-positive material in the dermis.

Findings:

• Kidney biopsy confirmed amyloid deposition in arterioles.
• Bone marrow biopsy diagnosed multiple myeloma.
• The patient was diagnosed with primary systemic amyloidosis associated with multiple myeloma.

Implications:

• This case underscores the multisystemic nature of amyloidosis.
• Early diagnosis and management are crucial for patients with co-existing multiple myeloma.
• Highlights the diagnostic utility of Congo red staining and polarized light microscopy.