Fibroblastic Rheumatism Versus Variant Disease of Multinucleate Cell Angiohistiocytoma

Area of Science:

• Dermatopathology
• Rheumatology

Background:

• Connective tissue diseases can manifest with diverse dermatological symptoms.
• Raynaud phenomenon and polyarthritis are common systemic features.

Observation:

• A 49-year-old woman presented with persistent finger and inframammary papulonodules.
• She exhibited symmetrical polyarthritis and Raynaud phenomenon.
• Skin biopsy revealed dermal proliferation of bland spindled cells and multinucleated giant cells.

Findings:

• Immunohistochemistry showed spindled cells positive for CD68/CD163, negative for smooth muscle actin.
• Multinucleated giant cells were negative for smooth muscle actin, CD68, and CD163.
• Absence of elastic fibers and minimal vascular increase were noted.

Implications:

• The findings present a diagnostic challenge between fibroblastic rheumatism and multinucleate cell angiohistiocytoma.
• Cyclosporine and methotrexate therapy led to symptom improvement.
• This case highlights the importance of integrating clinical and histopathological data for rare dermatological conditions.