12 July 2007 – Case of the Week #89

 

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We thank Dr. Julie E. Vitko, Southbay Hospital, SunCity Center, Florida (USA), for contributing this case.  To contribute a Case of the Week, please email info@PathologyOutlines.com with attachments of microscopic images (any size, we will shrink if necessary) in JPG, GIF or TIFF format, a clinical history, your diagnosis and any other images (gross, immunostains, etc.) that may be helpful or interesting.  We will write the discussion (unless you want to), list you as the contributor, and send you a check for $35 (US) for your time after we send out the case.  Please only send cases with a definitive diagnosis.

 

Case of the Week #89

 

Clinical History

 

A 22 year old Caucasian woman presented with right cervical adenopathy.  Her medical history was otherwise unremarkable.  A lymph node was excised.

 

Micro Images: image #1#2#3#4#5#6  

 

AFB and GMS stains were negative for fungi or microorganisms.  Serology was negative for toxoplasmosis, EBV or cat-scratch disease.

 

What is your diagnosis?

 

 

 

 

 

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

Diagnosis:

 

Kikuchi-Fujimoto’s lymphadenopathy

 

Discussion

 

This disorder, also called histiocytic necrotizing lymphadenitis and Kikuchi’s disease, was initially described in Japan and other Asian countries, but now is found worldwide.  It primarily affects young women, who present with cervical lymphadenopathy (tender or painless), fever and often leukopenia.  The etiology is unknown, although the prominent necrosis is due to apoptosis mediated by cytotoxic T cells (Mod Path 1997;10:231)

 

The microscopic picture is dominated by well circumscribed necrotic lesions, often with a starry sky appearance.  There is also karryorhexis, fibrin deposits, phagocytic and foamy histiocytes, plasmacytoid monocytes (two to three times larger than small lymphocytes with variable cytoplasm, round nuclei with open chromatin, small nucleoli, CD4+) and T cells (CD8+, cytotoxic phenotype).  There are no/rare plasma cells, neutrophils, follicular hyperplasia or atypia.  Occasionally, there is no overt necrosis (AJSP 1990;14:514).  Fine needle aspiration shows phagocytic histiocytes with peripheral nuclei and plasmacytoid monocytes.

 

The differential diagnosis includes lymphoma with necrosis, cat-scratch disease and lupus lymphadenitis.  Lymphoma may have prominent necrosis, but atypical cells should be present, and plasmacytoid monocytes are lacking.  Cat-scratch disease, caused by Bartonella henselae, has a clinical history of cat exposure with an initial skin papule.  Lymph nodes show prominent neutrophils and follicular hyperplasia, not present in Kukuchi’s disease.  Lupus lymphadenitis has paracortical necrosis and hematoxylin bodies, as well as a clinical history of lupus (Hum Path 1989;20:295).

 

Kikuchi’s disease is usually benign and self-limited (Ann Saudi Med 2005;25:319), although 3% of cases recur (AJSP 1995;19:798).

 

Additional references: AJSP 1994;18:219, Hum Path 1993;24:1114 (plasmacytoid monocytes), J Clin Pathol 1985;38:1252, eMedicine

 

 

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