Cytologic diagnosis of anaplastic large cell lymphoma

To identify characteristic cytomorphologic and immunocytochemical features of anaplastic large cell lymphoma (ALCL).

We reviewed all positive cytology cases from patients with histologically confirmed ALCL at the National Institutes of Health/National Cancer Institute for patient demographics, cytologic appearance and, when available, immunocytochemical staining pattern with markers for CD30, CD3, L26, CD15, leukocyte common antigen and epithelial membrane antigen (EMA).

Twenty-one cases were reviewed from seven patients (four males and three females) aged 2-83 years; 2 were human immunodeficiency virus positive. Specimens included exfoliative (cerebrospinal fluid, pleural fluid) and aspirated material (lymph node, lung, soft tissue). Commonly noted morphologic features included a smear pattern of largely dispersed cells with focal aggregates; variability in cell size with smaller and larger multinucleated giant forms (average cell size 42 microm); eccentric, round to oval nuclei; prominent nucleoli; a "ropy" chromatin pattern; and deeply basophilic, variably vacuolated cytoplasm. Necrosis was frequent. A proteinaceous background was prominent in cellular samples. Lymphoglandular bodies and lymphoid tangles were not prominent. Of cases evaluated immunocytochemically, 100% were positive for CD30, and 75% showed EMA positivity. Expression of other markers was variable.

ALCL has a distinct cytomorphologic appearance and immunocytochemical staining pattern such that a reliable diagnosis can be made on cytologic material.