SELNET clinical practice guidelines for bone sarcoma.

Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context.

Under-reporting of the energy intake in patients with type 2 diabetes.

BACKGROUND: In patients with type 2 diabetes mellitus (DM), an accurate assessment of food intake is essential for clinical nutritional management. Tools such as the food frequency questionnaire (FFQ) and 24-h food record (24HR) identify dietary habits in support of dietary planning. However, it is possible that these tools have reporting errors with respect to assessing food intake, particularly energy intake (EI). METHODS: A cross-sectional study was conducted in patients with type 2 DM. EI was assessed by the FFQ and 24HR tools. Resting energy expenditure (REE) was measured by indirect calorimetry. Data were analysed using a kappa test, t-test and Spearman's correlation coefficients. Under-reporting was assessed using the EI/REE ratio. Patients with values <1.18 and <1.10 for FFQ and 24HR, respectively, were considered as under-reporting. RESULTS: We evaluated 55 patients [mean (SD) 62.7 (5.3) years old, duration of diabetes 11.2 (7.3) years, 52.7% female]. The mean (SD) EI assessed by FFQ was 1797.7 (641.3) and as assessed by 24HR was 1624 (484.8) kcal day-1 . The mean (SD) REE was 1641.3 (322.3) kcal day-1 . The mean (SD) ratios FFQ/REE and 24HR/REE were 1.11 (0.38) and 1.01 (0.30), respectively. The tools showed a moderate agreement for under-reporting of EI (kappa = 0.404; P = 0.003). Moderate and positive correlations between REE were observed with FFQ (r = 0.321; P = 0.017) and 24HR (r = 0.364; P = 0.006). According to the tools, the under-reporting was observed in approximately 65% of patients. CONCLUSIONS: The majority of patients with type 2 DM under-reported their calorie intake, as assessed by FFQ and 24HR. REE showed a positive correlation with both tools.

Pituitary neuroendocrine tumors and differentiated thyroid cancer: do metabolic and inflammatory risk factors play roles?

PURPOSE: It is postulated that patients with different types of pituitary neuroendocrine tumors (PitNETs) may present a higher incidence of cancer. Factors underlying individuals becoming overweight, such as insulin resistance, hyperleptinemia, and low-grade inflammation, may play a role in the risk of differentiated thyroid carcinoma (DTC) in such patients. This study aimed to investigate the frequency of and obesity-related risk factors associated with DTC in patients with PitNETs. METHODS: This cross-sectional study involved 149 patients with nonacromegalic PitNETs (AG group), 71 patients with acromegaly (ACRO group), and 156 controls (CG group). All participants underwent insulin and blood glucose measurements with the determination of the homeostatic model assessment-insulin resistance (HOMA-IR) index, leptin, and high-sensitivity C-reactive protein (hsCRP), and they also underwent thyroid ultrasound. Clinically significant nodules were biopsied for subsequent cytopathological evaluation, and participants were operated on when indicated. RESULTS: Patients in the AG group had high levels of insulin resistance and significantly higher levels of leptin and hsCRP compared with those of patients in the ACRO group. There were no cases of DTC in the AG group; two findings, one incidental, of DTC occurred in the CG group, and three cases of DTC were present in the ACRO group. Acromegaly was associated with DTC after adjusted analysis. CONCLUSIONS: Our findings in patients with nonacromegalic PitNETs do not indicate a high risk for DTC despite the presence of metabolic and inflammatory risk factors for neoplastic events. In contrast, acromegaly promotes a greater risk of DTC.

Massive localised lymphoedema: a clinicopathological study of 22 cases and review of the literature.

BACKGROUND: Massive localised lymphoedema (MLL) is a rare, relatively recently described pseudosarcoma most often occurring in morbidly obese patients. AIM: To perform a retrospective review of all cases diagnosed as MLL. METHODS AND RESULTS: Clinical information was obtained. 22 morbidly obese adults (mean patient weight 186 kg) presented with unilateral, large soft tissue lesions of longstanding duration. Most lesions involved the thigh, but also occurred in the posterior calf and lower leg. Clinically, most lesions were regarded as representing benign processes, including pedunculated lipoma, lymphocoele or recurrent cellulites, although soft tissue sarcoma was also suspected in two cases. Grossly, all masses showed markedly thickened skin with a "cobblestone" appearance, and were ill-defined, unencapsulated, lobulate, and very large (mean size 31 cm, range 15-61.5 cm, mean weight 3386 g, range 1133-10,800 g). Histologically, all 22 cases showed striking dermal fibrosis, expansion of the fibrous septa between fat lobules with increased numbers of stromal fibroblasts, lymphatic proliferation and lymphangiectasia. Multinucleated fibroblastic cells, marked vascular proliferation, moderate stromal cellularity and fascicular growth raised concern among referring pathologists for atypical lipomatous tumour/well differentiated liposarcoma, angiosarcoma, and a fibroblastic neoplasm such as fibromatosis in 10, 2 and 1 case, respectively. CONCLUSION: The diagnosis of MLL continues to be challenging, in particular for pathologists. Awareness of this entity, clinical correlation and gross pathological correlation are essential in the separation of this distinctive pseudosarcoma from its various morphological mimics.

Temporal and spatial dynamics of blocking and ripening effects on bacterial transport through a porous system: a possible explanation for CFT deviation.

The studies on transport of particles across porous systems are based on the Colloid Filtration Theory (CFT). According to CFT, the collision efficiency is constant along the system length [J.N. Ryan, M. Elimelech, Colloids Surf. A: Physicochem. Eng. Aspects 107 (1996) 1-56]. Decreasing values of collision efficiency have been reported, a phenomenon that has been interpreted as a deviation from the CFT [X. Li, T.D. Scheibe, W.P. Johnson, Environ. Sci. Technol. 38 (2004) 5616-5625; N. Tufenkji, J.A. Redman, M. Elimelech, Environ. Sci. Technol. 37 (2003) 616-623; N. Tufenkji, M. Elimelech, Langmuir 20 (2004) 10818-10828; N. Tufenkji, M. Elimelech, Langmuir 21 (2005) 841-852]. This paper presents data on transport of Bacillus megaterium spores through quartz sand columns. The occurrence of consecutive phases of increase and decrease of the values of C/C(0), the effluent spore concentration expressed as a fraction of the influent spore concentration, is reported. These patterns of change in C/C(0) were interpreted as the result of the concomitant occurrence of blocking and ripening, the prevalence of these phenomena in different moments of the experiment, and the spatial distribution of the prevalence of blocking and ripening effects along the porous system. It is argued that this spatial distribution in the predominance of blocking and ripening, what leads to the intensification of ripening at the entrance of the porous system, might be a possible explanation for the reported deviation from the CFT for experimental conditions where ripening and blocking take place.

Low-grade myofibroblastic sarcoma of the parapharyngeal space.

Low-grade myofibroblastic sarcoma was recently described as representing malignant mesenchymal tumours that show myofibroblastic differentiation; few cases have been reported. Here, a low-grade myofibroblastic sarcoma of the parapharyngeal space is described. A 42-year-old man presented with swelling on the right side of the temporal bone. Based on histological and immunohistochemical features, the diagnosis of low-grade myofibroblastic sarcoma was established. The tumour had invaded the orbit and the brain, and therefore surgical excision was not possible. There are thought to have been no cases affecting this region reported previously in the English-language literature.

Phase I-II trial of ONYX-015 in combination with MAP chemotherapy in patients with advanced sarcomas.

ONYX-015 is a provisionally replication competent adenovirus with oncolytic activity in cells with malfunctioning p53. Sarcomas represent a rational target for this approach given the high frequency of p53 mutations (40-75%) and MDM-2 amplification (10-30%). We, therefore, undertook a phase I/II study of ONYX-015, days 1-5 every month administered intratumorally under radiographic guidance, in combination with MAP (mitomycin-C, doxorubicin, cisplatin) chemotherapy in patients with advanced sarcoma. Six patients were treated. Injected lesions included liver metastases in four patients and chest wall metastases in two patients. Sarcoma histologies were gastrointestinal stromal tumors (GIST, two patients), leiomyosarcoma (two patients), liposarcoma (one patient), and malignant peripheral nerve sheath tumor (1 patient). Dose escalation was performed from 10(9) plaque forming units (PFU)/dose (total dose of 5 x 10(9) PFU/cycle) to 10(10) PFU/dose (total dose of 5 x 10(10) PFU/cycle) without dose-limiting toxicity being encountered. Immunohistochemistry of the metastatic lesions prior to treatment showed that five out of six patients were positive for p53, while two patients also had mdm-2 overexpression. Adenoviral replication was detected in two out of six patient biopsies on day 5 of the first cycle, by in situ hybridization (ISH). Both patients were treated at the highest dose level. ONYX-015 viral DNA was detected by quantitative PCR in the plasma of 5/6 patients on day 5 of the first cycle, and up to day 12 (7 days after the last viral dose) in one patient who had extended sampling for viral kinetics performed, suggesting viral replication in sarcoma tissue. One patient with p53 mutation and MDM-2 amplification achieved a partial response to treatment that lasted 11 months. In conclusion, intratumoral administration of ONYX-015 in combination with MAP chemotherapy is well tolerated with no significant toxicity due to ONYX-015 being encountered. Detection of viral DNA in post treatment tumor specimens by ISH and detection of the ONYX-015 genome in the peripheral blood by quantitative PCR, up to 7 days after the last viral dose provide evidence for adenoviral replication. There was evidence of antitumor activity in one out of six patients. Further investigation of this approach in patients with recurrent sarcomas is warranted.

Primary breast sarcoma: clinicopathologic series from the Mayo Clinic and review of the literature.

Primary sarcomas of the breast are extremely rare, with less than 0.1% of all malignant tumours of the breast. Mayo Clinic Surgical Pathology database was searched for all breast sarcoma from 1910 to 2000. Pathology reports and slides were reviewed and tumour types were determined. Metaplastic carcinomas and phyllodes tumours were excluded. There were 25 women ranging in age 24-81 years (mean 45 years). All but one patient presented with a palpable lump. Mastectomy was performed in 19 patients and lumpectomy in five patients. Histopathological diagnoses were fibrosarcoma (six), angiosarcoma (six), pleomorphic sarcoma (six), leiomyosarcoma (two), myxofibrosarcoma (three), hemangiopericytoma (one) and osteosarcoma (one). Tumour size ranged from 0.3 to 12 cm (mean 5.7). Low-grade lesions were observed in 10 cases and high-grade in 15. Overall, mean follow-up was 10.5 years. Local recurrence was observed in 11 patients and ranged from 2 to 36 months (mean 15 m), while distant metastasis was observed in 10 patients (40%) affecting lungs, bones, liver, spleen, and skin. Of the 25 patients, 12 have died of disease and six of other causes. Five-year overall (OS) and cause-specific survival (CSS) were 66 and 70%, respectively. OS and DFS at 5 years were 91% for tumours < or =5 cm and 50% for tumours >5 cm. Tumour size was significantly associated with OS (risk ratio=1.3 per 1 cm increase; 95% CI, 1.02-1.7; P=0.036). There was no significant difference in OS or CSS between low- and high-grade lesions. In this series, tumour size was a more valuable prognostic factor than tumour grade.

Detection of fusion gene transcripts in fresh-frozen and formalin-fixed paraffin-embedded tissue sections of soft-tissue sarcomas after laser capture microdissection and rt-PCR.

The diagnosis of small round cell sarcomas is often very difficult, especially when only small biopsy specimens are available for examination. Recent studies have shown that some sarcomas have specific recurrent chromosomal translocations producing chimeric gene fusions, which can be detected by reverse transcription-polymerase chain reaction (RT-PCR), fluorescent in situ hybridization (FISH), or cytogenetic analysis. In this study, 12 cases of well-defined sarcomas including Ewings sarcoma/primitive neuroectodermal tumors (ES/PNET), synovial sarcoma (SS), alveolar rhabdomyosarcoma (ARMS), and desmoplastic small round cell tumors (DSRCT) were used to collect specific numbers of cells by laser capture microdissection (LCM), subsequently used for RT-PCR to detect specific chimeric gene transcripts. Tumor cells from fresh-frozen (FS) tissue sections and paraffin-embedded (PS) tissue sections from the same cases were compared directly to evaluate the sensitivity of FS and PS sections as the starting material for analysis. Samples were used for RNA extraction, RT-PCR analysis, and Southern hybridization with fluorescein-labeled internal probes followed by enhance chemiluminescence (ECL) detection. The fusion gene transcripts could be detected using 50 cells from FS materials in all cases and from 1 cell in 9 of 12 cases. For PS, a positive signal could be detected using 200 to 1000 cells in all cases, while weaker signals were detected using 50 cells in most cases. These results indicate that the fusion gene products from small round cell sarcomas can be detected by RT-PCR with 10 to 200 cells from FS and PS tissues. The sensitivity of RT-PCR with FS was 10- to 50-fold greater than with PS. These results also suggest that RT-PCR analysis for sarcoma fusion gene products can be successfully performed when only a few cells are available for analysis, although this is not recommended for routine clinical use.

Lipoblastoma-like tumour of the vulva: report of three cases of a distinctive mesenchymal neoplasm of adipocytic differentiation.

AIMS: We sought to delineate and describe three cases of a distinctive mesenchymal neoplasm of the vulva showing adipocytic differentiation and affecting young patients. METHODS AND RESULTS: In three patients between 13 and 38 years of age, the vulvar tumours had well-circumscribed borders and ranged in size from 35 to 100 mm. Histologically, they were well circumscribed and lobulated. The lobules were separated by thin fibroconnective tissue septa and were composed of slender spindle cells showing slightly eosinophilic cytoplasm with indistinct boundaries, uniform nuclei with finely granular chromatin, and no nucleoli. The cells were embedded in a richly myxoid stroma. The background in all three tumours was a 'chicken-wire', capillary vascular network resembling that seen in myxoid liposarcomas. Two tumours had scattered signet-ring-type lipoblasts and the third a large number of such lipoblasts. Clusters of mature adipocytes were entrapped in the tumours. None had mitotic figures, necrosis, or pleomorphism. The neoplastic cells stained positively for vimentin and were negative for other immunohistochemical markers. Treatment for all three tumours was enucleation alone. After follow-up of 10 years, 7 years, and 1 year, all patients are well with no evidence of disease. CONCLUSIONS: The benign behaviour of these neoplasms militates against the diagnosis of liposarcoma. We believe these are benign lesions of adipocytic differentiation akin to infantile lipoblastomas.

Wide spectrum screening keratin as a marker of metaplastic spindle cell carcinoma of the breast: an immunohistochemical study of 24 patients.

AIMS: Metaplastic spindle cell carcinomas may be difficult to distinguish histologically from other spindle cell lesions in the breast. Variable staining with cytokeratin immunomarkers has been reported for metaplastic carcinomas. We evaluated the diagnostic utility of anti-cytokeratin polyclonal antibody, wide spectrum screening keratin, to assess spindle cell breast lesions. METHODS AND RESULTS: Twenty-four patients with spindle cell breast carcinoma and 31 patients with benign or malignant spindle cell tumours were studied using a panel of antibodies directed against multiple cytokeratins (AE1/AE3, CAM5.2, wide spectrum screening keratin), epithelial membrane antigen (EMA), and vimentin. Sites of origin for the 31 controls included breast, bone, and soft tissue. All but one (95.8%) metaplastic carcinomas stained positively with wide spectrum screening keratin. Only rare or focal immunoreactivity was observed with AE1/AE3 in four cases; however, sensitivity of AE1/AE3 was improved in 13 cases using steam EDTA as an antigen retrieval technique. Three cases were immunoreactive with CAM5.2 and eight cases were immunoreactive with EMA. All control cases lacked immunoreactivity with the cytokeratin panel and EMA. The spindle cells in the metaplastic breast tumours (88%) and in the controls (97%) stained with vimentin. CONCLUSIONS: Wide spectrum screening keratin may be the most useful and convenient antibody in differentiating metaplastic spindle cell carcinoma from other spindle cell lesions in the breast.

ETV6 rearrangements in patients with infantile fibrosarcomas and congenital mesoblastic nephromas by fluorescence in situ hybridization.

Congenital mesoblastic nephroma (CMN) and infantile fibrosarcoma (IFS) are two pediatric tumors arising in the kidneys and soft tissues of infants, respectively. Recently, a t(12;15)(p13;q25) resulting in ETV6-NTRK3 gene fusion was detected in patients with IFS and in patients with the cellular type of CMN, suggesting a common pathogenetic pathway. We investigated the presence or absence of ETV6 rearrangements and numerical abnormalities of chromosome 11 by using fluorescence in situ hybridization on paraffin-embedded material from five cases of IFS, two of CMN, and one of mixed type (CMN and IFS) found in our files. In three cases of IFS, we found ETV6 gene rearrangement but a normal copy number of chromosome 11. One case each of IFS, the cellular type of CMN, and the mixed type (CMN and IFS) had both abnormalities. In a case of classic CMN, neither trisomy 11 nor gene rearrangement was found. It is possible that trisomy 11 is a later, nonessential event in the pathogenetic process or that this secondary aberration is associated with still-unrecognized clinical or biological characteristics. We confirmed that IFS and the cellular type of CMN are cytogenetically related and can occur synchronously in the same organ.

Extraskeletal myxoid chondrosarcoma: a light microscopic, immunohistochemical, ultrastructural and immuno-ultrastructural study indicating neuroendocrine differentiation.

AIMS: Extraskeletal myxoid chondrosarcoma is a rare low-grade soft-tissue sarcoma with locally aggressive and metastasizing potential. Extraskeletal myxoid chondrosarcoma has distinctive clinical, light microscopic, immunophenotypic, cytogenetic and ultrastructural features. Evidence that extraskeletal myxoid chondrosarcoma often shows neuroendocrine features was first provided by Chhieng et al. on the basis of an immunohistochemical and ultrastructural study of seven cases. Our study aims to further confirm by immunohistochemistry and ultrastructural studies, including immunoelectron microscopy, that extraskeletal myxoid chondrosarcoma indeed may show neuroendocrine differentiation. METHODS AND RESULTS: Fifteen cases of extraskeletal myxoid chondrosarcoma and seven control cases of skeletal chondrosarcomas were studied. Extensive immunohistochemical analysis was performed in all cases and ultrastructural studies were done in 11 extraskeletal myxoid chondrosarcomas and three skeletal chondrosarcomas. Immunoelectron microscopy was performed on one case each of extraskeletal myxoid chondrosarcoma and skeletal chondrosarcoma. Extraskeletal myxoid chondrosarcomas expressed neuron-specific enolase (100%), synaptophysin (87%), S100 (50%), PGP 9.5 (40%), and epithelial membrane antigen (25%). Co-expression of synaptophysin and PGP 9.5 was observed in six tumours. Skeletal chondrosarcomas showed expression of S100 protein, vimentin and neuron-specific enolase in all cases. Synaptophysin, chromogranin and PGP 9.5 were not expressed in any skeletal chondrosarcoma case. Ultrastructurally, extraskeletal myxoid chondrosarcoma was characterized by distinct cords of cells immersed in a glycosaminoglycan-rich matrix. The cells were rich in mitochondria, had well-developed Golgi apparatus and there were numerous smooth vesicles. In three cases there were easily found 140-180 nm diameter membrane-bound dense-core granules in cell bodies and in processes, unrelated to the Golgi, compatible with neurosecretory granules. Fewer such granules were present in the remaining extraskeletal myxoid chondrosarcoma cases, three of which also contained intracisternal tubules typical of extraskeletal myxoid chondrosarcoma. The skeletal chondrosarcomas had scalloped cell surfaces, prominent rough endoplasmic reticulum focally distended with secretory product, and lacked neurosecretory granules. Intermediate filaments were prominent in both extraskeletal myxoid chondrosarcoma and skeletal chondrosarcomas. Immunoelectron microscopy showed synaptophysin expression in the extraskeletal myxoid chondrosarcoma but not in the skeletal chondrosarcoma case. CONCLUSIONS: This study confirms that a substantial proportion of extraskeletal myxoid chondrosarcomas show immunophenotypic and/or ultrastructural evidence of neuroendocrine differentiation, and are unlikely to be related to conventional skeletal chondrosarcomas.

Grading in soft tissue tumors: principles and problems.

Histologic grading has been considered the most important prognostic factor for soft tissue sarcomas. Several grading systems have been proposed based on the assessment of morphologic features in heterogeneous groups of sarcomas. Currently, the French Federation of Cancer Centers (FNCLCC) and the National Cancer Institute (NCI) grading systems are the most commonly used. These systems are based on a few morphologic predictors of biologic behavior, which is justifiable because of the rarity of soft tissue sarcomas. Nonetheless, over- or underestimation of prognosis may occur because of an uneven representation of specific sarcomas with rather distinct biologic behaviors among studies of grading systems. In addition, lack of standardization of morphologic criteria and frequent omission of the influence of clinical factors on the final survival analyses preclude universal acceptance of a particular grading system. New advances in diagnostic imaging, quantitative morphometric technologies, cytogenetics, and molecular genetics, allied with alternative analytic data systems, may provide better validation, reproducibility, and prognostic capabilities for current and future grading systems. This article summarizes and critically analyzes the various important grading systems that have thus far been proposed and suggests alternatives for the elaboration of more reproducible systems with higher predictive capabilities.

Inflammatory pseudotumor and sarcoma of urinary bladder: differential diagnosis and outcome in thirty-eight spindle cell neoplasms.

We assessed diagnostic criteria among 38 spindle cell tumors of the urinary bladder and obtained follow-up in 36 patients. Patients comprised 28 males and 10 females aged 2.5 months to 87 years. Hematuria was the commonest presenting symptom (27 patients). After review and immunohistochemical workup, 17 patients had inflammatory pseudotumor (myofibroblastic tumor), 4 postoperative spindle cell nodule, 1 leiomyoma, 13 sarcoma (7 low-grade; 6 high-grade), and 3 carcinoma. Mean age was 38 years for pseudotumor (range 15 to 74), 65 for postoperative spindle cell nodule, 51 for sarcoma, and 76 for carcinoma. Size of pseudotumor averaged 4.4 +/- 0.7 cm (range 1.5 to 13.0), similar to sarcoma, 4.0 +/- 0.6 cm (range 0.5 to 7.0). Similar proportions of benign tumors and sarcomas had muscularis propria invasion. The criteria that best differentiated sarcoma from inflammatory pseudotumor were presence of necrosis at the tumor-detrusor muscle interface in muscle-invasive cases, and nuclear atypia. Sarcoma also had less prominent microvasculature, less variable cellularity, consistently > or =1 mitotic figure per 10 high-power fields, and predominant acute inflammation without plasma cells. p53 protein nuclear immunostaining was moderate, unlike the rare to absent staining in pseudotumors. Because all 12 sarcomas were desmin-negative, we did not call them leiomyosarcoma; they overlapped with benign tumor in epithelial, mesenchymal, and actin immunostaining. Among 12 sarcoma patients, 2 died of tumor (at 3 months). Two of four experienced tumor recurrence after partial cystectomy (2 and 26 months). No pseudotumors recurred after transurethral resection or partial cystectomy, although one patient, 5 months after transurethral resection, had histologically identical pseudotumor that the surgeon considered residual. Another patient with pseudotumor, not a candidate for tumor ablation after transurethral resection, had continued tumor growth and he died of urosepsis. In conclusion, inflammatory pseudotumor, although overlapping with sarcoma in presentation, age range, and size, does not metastasize and remains histologically distinct from low-grade sarcoma.

Solitary fibrous tumor: a study of cytologic features of six cases diagnosed by fine-needle aspiration.

Solitary fibrous tumor (SFT) is a spindle-cell neoplasm most often presenting as a pleural-based tumor but increasingly recognized in other locations. Few reports have described the cytologic features of SFTs. Six cases of SFT diagnosed by fine-needle aspiration (3 pleura, 2 retroperitoneum, and 1 orbit) were identified in the Mayo Clinic files. The smears (Papanicolaou-stained) and corresponding histologic specimens were reviewed. Immunohistochemical staining for CD34 was performed in all cases. The cytologic findings were similar in all cases. The tumor cells were oval to polygonal, with cellularity ranging from scant to moderate. The background contained irregular ropy fragments of collagen and a few inflammatory cells. Most cells were dispersed singly, but all cases contained irregular, loose aggregates of cells enmeshed in a collagenous matrix. The nuclei were uniformly bland, with evenly distributed, finely granular chromatin. All cases were immunoreactive for CD34. SFT has distinctive cytologic features that allow diagnosis in cytologic specimens with the help of appropriate immunocytochemical stains on accompanying tissue biopsy specimens. Distinctive cytologic findings predictive of clinical behavior were not identified.