Cutaneous Rosai-Dorfman disease: a case report

Area of Science:

• Dermatopathology
• Immunohistochemistry
• Cutaneous Manifestations

Background:

• A 40-year-old female presented with a 2-year history of progressively enlarging asymptomatic nodules on her lower extremities.
• Initial symptoms included a dark spot on the right thigh, followed by the development of similar nodules on the leg and lesions on the buttock.

Observation:

• Physical examination revealed indurated, heterogeneous plaques with hyperpigmented rims on the right thigh and left lower extremity.
• No cervical or supraclavicular lymphadenopathy or organomegaly was detected.

Findings:

• Preliminary work-up for infectious and autoimmune diseases was negative.
• Dermal biopsies showed a nodular inflammatory infiltrate composed of histiocytes, plasma cells, and lymphocytes.
• Histiocytes stained positive for S-100, CD68, and CD45, with observed Russell bodies and emperipolesis. Microorganism stains were negative.

Implications:

• The histopathological findings, particularly the immunohistochemical profile, are crucial for diagnosing this rare cutaneous condition.
• This case highlights the importance of thorough histopathological examination in evaluating persistent skin lesions.
• Understanding the cellular infiltrate and marker expression aids in differentiating from other nodular dermatoses.