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26 February 2014 - Case of the Week #302

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Case of the Week #302

Clinical History:
A 45 year old woman presented with a right breast mass, which was biopsied.

Micro images:

What is your diagnosis?

Rosai-Dorfman disease

Rosai-Dorfman disease, also called sinus histiocytosis with massive lymphadenopathy, is a disorder of massive lymph node involvement that may also involve extranodal sites. It often presents with systemic symptoms (fever, leukocytosis, anemia), and most commonly involves the skin, subcutis / soft tissue, upper respiratory tract, bone, eye or CNS. Cases in the breast are rare.

Grossly, there are circumscribed, often multinodular masses in the breast stroma, which typically do not involve the dermis or subcutis. Histologically, large histiocytes are present with abundant pale eosinophilic cytoplasm and mildly atypical round vesicular nuclei (Am J Surg Pathol 1997;21:664). The background shows lymphocytophagocytosis (emperipolesis) in a background of mature lymphocytes and plasma cells. The histiocytes are immunoreactive for S100 and CD68 and negative for CD1a.

The differential diagnosis includes other histiocyte-like disorders:
Erdheim-Chester disease: usually a systemic disease with large foamy histiocytes containing lipid
Idiopathic granulomatous mastitis: granulomas with epithelioid histiocytes
Langerhans cell histiocytosis: Langerhans cells are large, ovoid with pale pink cytoplasm and indented bland nuclei; CD1a+
Tuberculosis or other infectious granulomas
Benign fibrous histiocytoma: storiform pattern of spindled and bland fibroblasts and histiocyte-like cells in mid-dermis and subcutaneous tissue with infiltrative margins but sparing epidermis.

Rosai-Dorfman disease usually resolves spontaneously, although systemic cases may cause death. Recent reports suggest that a subset of Rosai-Dorfman disease exhibit features of IgG4-related disease (Korean J Pathol 2012;46:489, Am J Clin Pathol 2013;139:622, but see Am J Clin Pathol 2013;140:395 )

Nat Pernick, M.D., President
and Palak Thakore, Associate Medical Editor
PathologyOutlines.com, Inc.
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Email: NatPernick@Hotmail.com
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