[514] Cutaneous Marginal Zone Lymphoma: A Multi-Institutional Clinicopathologic Study

Jessica Kozel, Louis P Dehner, Maria Y Hurley, John L Frater. Saint Louis University, St Louis, MO; Washington University, St Louis, MO

Background: It is unclear whether the immunophenotyic and morphologic features of primary cutaneous marginal zone lymphoma (CMZL) significantly differ from marginal zone lymphomas occurring in other sites. Recent studies suggest that a subset of pts are at risk of developing systemic disease.
Design: A search of the pathology files of 2 tertiary care institutions was performed. Clinicopathologic features of the identified cases were reviewed.
Results: 40 pts (73 biopsies) were identified.Mean age at diagnosis was 54 years (range 19-85y); M:F ratio was ∼1.8:1. Pts presented with ≥1 lesions described as plaques, nodules, papules, or tumors, in the following sites: head and neck (18 biopsies), trunk (30 biopsies), upper extremities (14 biopsies), or lower extremities (5 biopsies); 5 pts presented with concomitant involvement of more than one body region. The most common growth patterns were nodular and diffuse, with sparing of the overlying epidermis. Cells were CD43+ (55% of cases), BCL2+ (82%), and CD10+ (3.5%), and were uniformly negative for BCL6 (29 cases) and CD5 (28 cases). CD21 highlighted follicular colonization in 12 tested cases, and highlighted the malignant cells in 1 case. IgH gene rearrangement studies were (+)in 6/12 (50%) of tested cases, and kappa/ lambda immunoglobulin light chain ISH or IHC had a monoclonal pattern of reactivity in 23/29 (79%). 5 pts had antecedent biopsies that, although suspicious, were nondiagnostic for lymphoma. 1/8 tested pts had a positive staging bone marrow bx. Pts were treated with localized irradiation (2 cases), rituximab (5 cases), or intralesional steroids (5 cases); most pts (∼70%) received no therapy besides excisional biopsy. 6 patients had recurrent disease, all in the same body region as at original presentation. Besides the pt with bone marrow involvement, no pts to date developed lymphoma outside the skin.
Conclusions: 1) A CD5-/CD10-/BCL6- phenotype was, with 1 exception, observed in all tested cases. CD21 aided identification of follicular colonization. 2) percentages of CD43 and BCL2 positive cases were similar to those observed in marginal zone lymphoma occurring in other sites. 3) Kappa/ lambda ISH and IHC were more sensitive than IgH gene rearrangement studies, likely due to technical problems associated with extraction of sufficient DNA for PCR studies. 4)CMZL has a low likelihood of localized recurrence and very rarely disseminates, perhaps justifying a conservative approach to clinical management when the pathologic diagnosis is certain.
Category: Dermatopathology

Monday, March 19, 2012 9:15 AM

Platform Session: Section F, Monday Morning


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