Aspiration cytopathology of lymphoblastic lymphoma and leukemia: the MCV experience

Malignant lymphoma, lymphoblastic type (LL), and acute lymphoblastic leukemia (ALL) are two well-known pediatric malignancies whose diagnoses are typically established by surgical tissue biopsy and/or bone marrow examination. The status of fine-needle aspiration (FNA) biopsy in the diagnosis and management of these lymphoblastic malignancies is controversial. We present our experience from the past 7 years using FNA in children from 10 months to 15 years (mean age 10.5 years) of age with lymphoblastic cancers; in addition, two adult patients with ALL are included. Superficial FNA was performed in 16 cases (one patient had two aspirations 16 months apart). Eight patients were diagnosed with LL, six with ALL, and the one patient with two separate aspirates had lymphoblastic transformation of chronic myelogenous leukemia (CML). Five patients presented with the superior mediastinal syndrome. Sites of FNA included lymph node (nine cases), parotid gland (one), and soft tissues of the neck (four), buttock (one), and forehead (one). There were no complications from FNA. Except for one case (case 8), the patients with ALL and CML were previously diagnosed and treated for their disease, and FNA was performed primarily for the detection of disease recurrence. Conversely, in all eight children with LL, FNA was performed as the initial procedure to establish a primary diagnosis in previously well individuals. All eight LL patients responded-some dramatically-to chemotherapy. Two patients with LL and one with lymphoid blast crisis arising in CML had subsequent surgical biopsies that confirmed the FNA diagnosis. Immunophenotyping performed from 15 of 16 aspirates confirmed the T cell derivation of all cases of LL and 4 of 6 of ALL. Two of the ALL cases had a pre-B cell phenotype. Sufficient cells were obtained by FNA for flow cytometric DNA analysis in 9 of 16 cases. All cases but one were diploid, and 6 of 9 showed a high (> 6%) S phase. Our experience suggests that, when combined with immunologic phenotyping, definitive initial pathologic diagnosis of LL and recurrent ALL is possible and preferable using only aspiration cytopathology. It should be considered as part of the initial evaluation and management whenever a mass lesion appears in a child with a suspected lymphoblastic neoplasm. It can preclude the need for a surgically procured piece of tissue in those with a mediastinal mass and the superior mediastinal syndrome.