A 69-year-old woman with a history of diabetes mellitus complained
of weakness and weight loss. The patient was without
hepatosplenomegaly, lymphadenopathy, or other palpable masses.
||(4.8-10.8)10e9/L (Adjusted for NRBCs)
Because of pancytopenia, a bone marrow aspirate was performed.
Bone marrow aspirate differential:
Marrow % Peripheral Blood %
Bands 8.0 10
Neutrophils 6.0 50
Lymphocytes 18.0 38
NRBCs 19.0 8
Flow cytometric analysis of bone marrow aspirate:
CD l9 50
CD 5 3
CD 10 58
CD 34 8
Cyto µ Pos
CD 14 1
CD 45 34
The blasts seen in the bone marrow aspirate were moderate to large
immature cells with coarsely granular nuclear chromatin and cytoplasmic
vacuoles. Multiple nucleoli were noted. The cytoplasmic vacuoles
stained positive for neutral lipids with Oil Red O.
Flow cytometry studies of the bone marrow aspirate were positive for
CD 45, CD 19, and CD 10, but negative for CD 34. The cells were
positive for cytoplasmic mu. This pattern, while not specific, is quite
typical of Burkitt's lymphoma/leukemia or small noncleaved cell
lymphoma. CD 19, 20, and 21 are usually positive on the blasts of
Burkitt's, whereas CD 34 is absent. CD 10 expression is common
(positive in up to 3/4 of cases).
This case is unusual in several aspects. Most patients present with
Burkitt's lymphoma within the first two decades of life, however, cases
are reported into the 9th decade. Although most often an extranodal
proliferation, in the United States, Burkitt's lymphoma most commonly
presents as an abdominal mass. This patient had no evidence of disease
outside of the bone marrow. The cellular aspirate and high blast count
suggest the extensive marrow involvement as is usual in reported cases
of Burkitt's lymphoma of the marrow. Despite this degree of
involvement, frankly leukemic peripheral blood involvement is uncommon.
The virtually indistinguishable nature of a acute lymphoblastic
leukemia (L3) and small noncleaved cell lymphoma is discussed in a
recent review of 45 cases of L3 acute lymphoblastic leukemia in which
it was concluded that the major difference between the two was clinical
presentation. Non-Hodgkin's lymphoma as an isolated bone marrow finding
is considered rare and often difficult to diagnose. None of the
Ponzonni cases were small noncleaved cell lymphomas.
Malignant lymphoma, small noncleaved cell (Burkitt's lymphoma)/Acute
lymphoblastic leukemia (L3).
Brunning RD et al: Bone marrow involvement in Burkitt s lymphoma.
Cancer 40:1771-1779, 1977.
Dayton VD: L3 acute lymphoblastic leukemia comparison with small
non-cleaved cell lymphoma involving the bone marrow. Amer J Clin Path
Ponzoni M, Chin-Yang L: Isolated bone marrow non-Hodgkin s lymphoma:
a clinical pathologic study. Mayo Clinic Proceedings 69:37-43,
David C. Winston, M.D., Ph.D. Department of Pathology University of
Virginia Health System
Donald J. Innes, Jr., M.D. Department of Pathology University of
Virginia Health System
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