[1215] CD30 Expression in Mastocytosis.

Angela R Arredondo, Charay D Jennings, Luke Shier, Uma Sundram, Jason Gotlib, Tracy I George. Stanford University School of Medicine, CA; University of Alberta Hospital, Edmonton, Canada

Background: Strong expression of CD30 has been reported in aggressive or leukemic systemic mastocytosis (SM) with low or absent expression in indolent SM in a recent review (unpublished observations). This contrasts with one prior report stating no expression of CD30 in 22 cases of SM.
Design: In this study, we evaluated expression of CD30 (Ber-H2) in paraffin-embedded whole bone marrow biopsy sections, bone marrow biopsy tissue microarrays and skin biopsies using standard immunohistochemical techniques. Samples were from patients with cutaneous (n=12) and systemic mastocytosis (n=23), myelomastocytic leukemia (n=2), monoclonal mast cell activation syndrome (n=2) contrasting with reactive/normal marrows (n=8), myeloproliferative neoplasms (MPN, n=16), myelodysplastic syndromes (MDS, n=18), MDS/ MPN neoplasms (n=6) and myeloid neoplasm with eosinophilia and PDGFRA (n=1). Positive expression of CD30 was graded as 1+ (weak) versus 2+/3+ (moderate/strong).
Results: CD30 highlighted >5% mast cells in mast cell leukemia (4/4), aggressive SM (3/3), indolent SM (3/3), SM with an associated hematological non-mast cell disease (SM-AHNMD, 6/11), and cutaneous mastocytosis (6/12). Expression was 1+ in 2/4 mast cell leukemias, 2/3 aggressive SM, 2/3 indolent SM, 1/6 SM-AHNMD, and 1/6 cutaneous mastocytosis. No expression of CD30 was seen in myelomastocytic leukemia, smoldering SM, monoclonal mast cell activation syndrome, reactive/normal marrows including mast cell hyperplasia, MDS, MDS/ MPN, and myeloid neoplasm with eosinophilia. Focal scattered CD30 positivity (2-5% of mononuclear cells) was seen in 2/16 MPN marrows including chronic eosinophilic leukemia, NOS and chronic myelogenous leukemia.
Conclusions: CD30 expression is present in cutaneous and systemic mastocytosis including aggressive and indolent forms of mast cell disease, but is generally not present in MDS and MPN. The differential diagnosis of CD30+ infiltrates in marrow and skin now includes mastocytosis emphasizing the importance of lineage specific markers when evaluating neoplasms in these locations.
Category: Hematopathology

Monday, February 28, 2011 1:00 PM

Poster Session II # 182, Monday Afternoon


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