Fine-needle aspiration biopsy of granulocytic sarcoma - A clinicopathologic study of 27 cases

BACKGROUND. Because of morphologic similarities, the differential diagnosis of granulocytic sarcoma (GS) in fine-needle aspiration (FNA) specimens inc ludes non-Hodgkin or Hodgkin lymphoma, extramedullary hematopoiesis, poorly differentiated carcinoma, and infection. METHODS. Twenty-six FNAs and 1 pleural effusion fluid specimen of GS obtain ed from 23 patients were reviewed for cytomorphologic features and clinical characteristics. The cases were categorized as blastic, immature, or matur e GS based on the population of the cells present on the smears. RESULTS. The patients included 18 men and 5 women (mean age, 54 years). Asp iration sites included subcutaneous or soft tissue (15 cases), lymph nodes (5 cases), bones (3 cases), testis (1 case), ileum (1 case), and liver (1 c ase). One sample of pleural effusion fluid also was included. Review of the patients' clinical history revealed that GS was secondary to chronic myelo genous leukemia (CML) in 17 patients, was secondary to chronic myelomonocyt ic leukemia (CMML) in 2 patients, and was secondary to acute myelogenous le ukemia in 2 patients. GS preceded the manifestation of CML in one patient a nd of CMML in another patient. Based on the proportions of cells, morpholog ic classification was attempted and revealed blastic GS in 8 aspirates and 1 pleural effusion fluid specimen, immature GS in 13 aspirates, and mature GS in 5 aspirates. Twelve of 22 specimens from extranodal sites (55%) demon strated lymphoglandular bodies In the background. Five aspirates showed rar e eosinophilic myelocytes. Auer rods were not identified in any of the aspi rates. Immunophenotypic and histochemical studies confirmed myeloid and/or myelomonocytic differentiation. CONCLUSIONS. GS especially can be confused with non-Hodgkin lymphoma becaus e of morphologic similarities of the blasts to large cell lymphoma, the pre sence of lymphoglandular bodies, and the rarity of Auer rods and eosinophil ic myelocytes. In conjunction with careful cytomorphologic evaluation, know ledge of die patient's clinical history and use of appropriate immunophenot ypic studies should lead to a correct diagnosis. Cancer (Cancer Cytopathol) 2000;90:364-372. (C) 2000 American Cancer Society.