Fine-Needle Aspiration of Leiomyosarcoma: A Correlative Cytohistopathological Study of 96 Tumors in 68 Patients Jerzy Klijanienko, M.D., 1 * Jean-Michel Caillaud, M.D., 2 Re ´al Lagace ´, F.R.C.P.C., M.D., 3 and Philippe Vielh, M.D., Ph.D. 1 To better define the cytological features of various leiomyosar- coma (LMS) variants, we reviewed the fine-needle aspiration ma- terial and the corresponding histologic sections of 96 tumors in 68 patients. Histological variants of LMS were as follows: 80 (83.3%) were of the classical/usual, seven (7.3%) were epithelioid, and nine (9.4%) were myxoid. Review of original cytology reports showed that 23 (24%) tumors were diagnosed as LMS and 69 (71.8%) as other types of malignancies. Two (2.1%) cases were reported as suspicious and two (2.1%) were unsatisfactory. The classical variants of LMS were characterized cytologically by various proportions of spindle-shaped, cohesive, small- or large- sized cells arranged in parallel alignment. Large spindle, round, binucleated, giant cells with intracytoplasmic granulations were frequently seen. Blunt-ended nuclei, intranuclear inclusions and mitotic figures were occasionally seen, as well as stromal frag- ments. The epithelioid tumors were composed of an admixture of small and large, spindle-shaped and round cells, also arranged in parallel alignment. Tumor cells with granular cytoplasm, blunt- ended nuclei, intranuclear inclusions, mitotic figures, fibrous or myxoid stroma were not observed. The myxoid tumors disclosed large amounts of background myxoid matrix containing large spindle-shaped and giant cells. Entities such as leiomyoma, ma- lignant peripheral nerve sheath tumor, monophasic synovial sar- coma, and malignant fibrous histiocytoma should be considered in the differential diagnosis of LMS of the classical type. Epithe- lioid leiomyoma may share similar cytological features with epi- thelioid LMS. The cytological features of the myxoid variant of LMS can be easily confused with other types of benign and malignant mesenchymal tumors depicting degenerative myxoid changes and/or a myxoid matrix component. Diagn. Cytopathol. 2003;28:119 –125. © 2003 Wiley-Liss, Inc. Key Words: leiomyosarcoma; cytology; aspiration Leiomyosarcomas (LMS) account for 5–10% of soft tissue sarcomas. 1 Because these neoplasms can be confused with other benign and malignant mesenchymal tumors, we felt that a cytological and histological correlative study could assess the effectiveness of fine-needle aspiration (FNA) cytology in the precision of the diagnosis of LMS. The preoperative diagnosis of these tumors provides useful in- formation in guiding their management. Although several cytomorphological studies of LMS have been published, 2–39 the correlative cytohistological studies are limited and do not provide, in our opinion, sufficient valuable morphologic criteria supporting this method of diagnostic investiga- tion. 3,8,12,17,25,38,39 In an attempt to better define the cytomorphologic diag- nostic criteria of LMS, we undertook a comparative cyto- histological study on a series of LMS treated at the Institut Curie. Materials and Methods A retrospective survey of the cytopathology files of the Institut Curie from 1954 to June 2001, which included over 270,000 cases, disclosed 1,695 mesenchymal tumors of soft tissue (specimens of pleural and intraabdominal effusions and pediatric tumors were not included in the study). All clinical charts of adult patients whose tumors were evalu- ated by cytology were reviewed to identify the available corresponding histologic material and to access the pathol- ogy reports. Moreover, clinical information included age, sex, primary vs. recurrent/metastatic nature, tumor size, tumor site, history of previous tumors, and therapy. All available histologic slides were reviewed and reclas- sified according to recent morphological criteria. 1 Seventy- four cases with histologically confirmed LMS, with both cytological and histological available material, formed the initial patient study group. Six cases of LMS of the gastro- intestinal tract 40 and one case with incomplete pathological documentation were excluded from the present series. 1 Department of Tumor Biology, Institut Curie, Paris, France 2 Biodoxis, Paris, France 3 CHU de Que ´bec-L’Ho ˆtel-Dieu de Que ´bec, Que ´bec, Canada * Correspondence to: Jerzy Klijanienko MD, Department of Tumor Bi- ology, Institut Curie, 26, rue d’Ulm 75248 Paris Cedex 05, France. E-mail: jerzy.klijanienko@curie.net Received 15 August 2002; Accepted 14 November 2002 DOI 10.1002/dc.10249 Published online in Wiley InterScience (www.interscience.wiley.com). © 2003 WILEY-LISS, INC. Diagnostic Cytopathology, Vol 28, No 3 119