Sinus histiocytosis

Sinus histiocytosis, abbreviated SH, is a common finding in lymph nodes.

It should not be confused with Rosai-Dorfman disease (also known as sinus histiocytosis and massive lymphadenopathy).

General

• Benign.
• Non-specific finding.

Microscopic

Features:

• Sinuses distended with histiocytes - key feature.
• Plasma cells increased.

DDx:

• Rosai-Dorfman disease - histiocyte nuclei large (~2-3x lymphocyte) and round with a prominent nucleoli.
• Dermatopathic lymphadenopathy - histiocytes have (melanin) pigment.

Images

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  SH - intermed. mag.

• 

  SH - high mag.

• 

  SH - high mag.

Sign out

• The finding is often ignored; may be signed out as morphologically benign lymph nodes.

See also

• Lymph node pathology.
• Dermatopathic lymphadenopathy