[1336] Soft Tissue Rosai Dorfman Disease: A Large Series with Detection of SV40 Antigen in Select Cases

MK Klassen-Fischer, A Auerbach, W Al-Daraji, JC Fanburg-Smith. Armed Forces Institute of Pathology, Washington, DC

Background: Soft tissue Rosai-Dorfman Disease (STRDD) is rare, previously reported only as single cases and few series. Simian virus 40 (SV40), a polyomavirus, has been identified in lymphoid processes and has a controversial role in neoplasia etiology. Occasional cytoplasmic pink granular inclusions led us to explore a viral etiology.
Design: Only unpublished STRDD from our files with adequate material, soft tissue location, and diagnostic confirmation, were included; IHC and follow-up obtained.
Results: 19 STRDD patients, 5 male and 14 female, had 34 lesions; six with 2-6 lesions. Ages ranged from 8-81 years, mean and median 43 years. STRDD locations: trunk or proximal extremity (n=20), distal extremity (n=9), abdominal (n=3), face (n=1), and unknown subcutis site (n=1). Sizes ranged 0.5 to 13.7 cm (median 2.4 cm). Previous disease included lymphoma, buttocks injection site, diabetes and hypothyroidism, and radiation for chronic dermopathy. No patients had a preceding or concurrent known viral infection; only one had lymphadenopathy. None were known to be immunocompromised. All STRDD were rapidly growing. Initial pathologic diagnosis ranged from RDD or inflammatory pseudotumor to inflammatory malignant fibrous histiocytoma. Grossly STRDD were multilobulated, tan-yellow and firm; morphologically, circumscribed and subcutaneous. All had sheets of polygonal histiocytes with abundant pale eosinophilic cytoplasm, emperipolesis, plasma cells and lymphocytes scattered and within clusters. Focal spindle cell change and mild pleomorphism were each observed in 3 patients; 2 had focal necrosis, none mitoses. Small granular pink cytoplasmic inclusions were observed. By IHC, all STRDD were positive for S100 protein, negative for CD1a, EBV and LMP, yet 3 (all abdominal, one multicentric) of 9 were focally positive for cytoplasmic SV40. All were treated by local excision. Follow-up on 15 patients over 8-16 years revealed recurrence in four patients with persistent multiple lesions, one with abdominal location. There were no metastases.
Conclusions: STRDD is a rapidly evolving, mostly solitary and non-recurrent trunk and proximal extremity subcutaneous lesion in middle aged females. One-third can have persistent multicentric disease. It is important to recognize STRDD, to separate it from malignancy. EBV/LMP were negative but SV40 was positive in 3 patients with abdominal STRDD, one with multicentric persistent disease. The relationship of SV40 to the evolution of abdominal STRDD should be further explored.
Category: Infections

Monday, March 9, 2009 1:00 PM

Poster Session II # 195, Monday Afternoon