A case of cutaneous plasmacytosis

Area of Science:

• Dermatology
• Pathology
• Immunology

Background:

• Cutaneous plasmacytosis is a rare disorder characterized by plasma cell infiltrates in the skin.
• The condition can present with various erythematous lesions, posing diagnostic challenges.

Purpose of the Study:

• To report a unique case of cutaneous plasmacytosis in a 51-year-old patient.
• To describe the clinical presentation, histopathological findings, and immunophenotype of the plasma cell infiltrate.

Main Methods:

• Clinical examination of erythematous lesions on the femur, perioral, and abdominal areas.
• Histopathological analysis of skin biopsy specimens.
• Immunohistochemical staining for plasma cell markers (CD79a, CD138).

Main Results:

• Histopathology revealed dense, mature plasma cell-dominant inflammatory infiltrate in the deep dermis and subcutaneous tissue.
• The infiltrating plasma cells were positive for CD79a and CD138, confirming their plasma cell origin.
• The patient presented with chronic infiltrated erythema on the right lower lateral femur and perioral and abdominal erythema.

Conclusions:

• The findings support the diagnosis of cutaneous plasmacytosis based on clinical and histopathological evidence.
• Immunophenotyping is crucial for confirming the nature of the infiltrating cells.
• This case adds to the literature on rare dermatological conditions involving plasma cell proliferation.