Rheumatoid Nodule - DermAtlas - Dermatology Image Atlas

Contributor

Greg Hosler, MD, PhD

Diagnosis

rheumatoid nodule

Body Site

knee

Age

11 years

Pigmentation

light

Organization

discrete

Color

brown

Morphology

nodule

Pattern

solitary extensor surfaces

Comments

The patient is a little young than typically seen but the histology is classic. Rheumatoid nodules are in the category of palisading granulomatous dermatitis. The differential diagnosis includes deep granuloma annulare, infection, foreign body, and perhaps epithelioid sarcoma. Rheumatoid nodules are characterized by fibrinoid change of the stroma, giving the granulomas a "red" appearance at low power, surrounded by palisading histiocytes. Scattered neutrophils are a common finding.

Description

Higher power shows the eosinophilic alteration of the dermis, with fibrinoid degeneration. Scattered neutrophils are present in the center of the granulomas. There are palisading histiocytes.

Image Added

5/17/2007 18:02:01

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Other Resources

PubMed Medline Plus Medscape

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