BACKGROUND: Malignant plasma cells ofmultiple myeloma (MM), or plasma cell leukemia (PCL), may present highly variable morphologic aspects. Adult T-cell leukemia-lymphoma (ATLL) is a peripheral T-cell neoplasm composed of highly pleomorphic lymphoid cells. We report an unusual case ofprimary PCL with misleading cellular morphology and some clinical and biologic similarities simulating ATLL. CASE: A 40-year-old Caribbean man presented with asthenia, epistaxis and diffuse bone pain. Blood cell count showed anemia and thrombocytopenia and a hyperleukocytosis composed of deeply basophilic cells with a polylobulated nucleus resembling flower cells. An ATLL diagnosis was given at first, without ruling out the possibility of a PCL diagnosis. Hypercalcemia and lytic bone lesions were compatible with both diagnoses. Immunophenotyping was key to the diagnosis of primary PCL. CONCLUSION: Some clinical and biological overlap may exist between PCL and ATLL, leading to a false diagnosis or delaying a correct one. An accurate cytologic analysis leading to a rapid detection of plasma cell markers is essential for an early diagnosis.
BACKGROUND: Malignant plasma cells ofmultiple myeloma (MM), or plasma cell leukemia (PCL), may present highly variable morphologic aspects. Adult T-cell leukemia-lymphoma (ATLL) is a peripheral T-cell neoplasm composed of highly pleomorphic lymphoid cells. We report an unusual case ofprimary PCL with misleading cellular morphology and some clinical and biologic similarities simulating ATLL. CASE: A 40-year-old Caribbean man presented with asthenia, epistaxis and diffuse bone pain. Blood cell count showed anemia and thrombocytopenia and a hyperleukocytosis composed of deeply basophilic cells with a polylobulated nucleus resembling flower cells. An ATLL diagnosis was given at first, without ruling out the possibility of a PCL diagnosis. Hypercalcemia and lytic bone lesions were compatible with both diagnoses. Immunophenotyping was key to the diagnosis of primary PCL. CONCLUSION: Some clinical and biological overlap may exist between PCL and ATLL, leading to a false diagnosis or delaying a correct one. An accurate cytologic analysis leading to a rapid detection of plasma cell markers is essential for an early diagnosis.