Retroperitoneal mass presentations of B‐immunoblastic sarcoma

A clinicopathologic analysis of nine patients with B‐immunoblastic sarcoma (B‐IBS) presenting as a bulky lymph node‐based retroperitoneal mass is reported. The histologic and immunologic findings, similar to those reported in B‐IBS presenting in various other nodal and extranodal sites, support the recognition of this aggressive large cell non‐Hodgkin's lymphoma (NHL) as a distinct pathologic entity. The patients, with a mean age of 60.5 years, presented for evaluation of abdominal pain and a palpable abdominal mass. Four patients were Stage II or IIE, one Stage III, and four Stage IV; eight of nine had B symptoms. Chemotherapy (cyclophosphamide, doxorubicin, vincristine, prednisone, bleomycin [CHOP‐B] or cyclophosphamide, doxorubicin, vincristine, methotrexate with leucovorin rescue, cytarabine [ACOMLA]) yielded significant palliation in five patients (mean survival, 12.3 months); three untreated patients and one receiving radiation treatment (XRT) died within 1 month from diagnosis. There was a striking predilection for pleuropulmonary involvement in disseminating disease. The initial blood lymphocyte count correlated significantly with survival (correlation coefficient, 0.84). The one durable complete remission (CR) was obtained in a patient who received substantial surgical debulking before chemotherapy. Cancer 56: 1733‐1741, 1985.