Genomic and transcriptomic comparison of post-radiation versus sporadic sarcomas.

Post-radiation sarcomas are rare secondary cancers arising from radiation therapies. To date, few genetic specificities have been described for such malignancies and the oncogenesis of sarcomas with complex genetics (both sporadic and post-radiation) remains largely misunderstood. We performed genomic and transcriptomic analyses on 77 post-radiation sarcomas using DNA-array and RNA sequencing. Consequently, we were able to investigate changes in copy number variations, transcriptome profiling, fusion gene expression, and mutational landscapes. We compare these data to a reference cohort of 93 sporadic sarcomas. At genomic level, similar chromosomal complexity was observed both in post-radiation and sporadic sarcomas with complex genetics. We found more frequent CDKN2A and CDKN2B (coding for p14/p16 and p15 proteins, respectively; at 9p21.3) losses in post-radiation (71%) than in sporadic tumors (39%; P = 6.92e-3). Among all detected fusion genes and punctual variations, few specificities were observed between these groups and such alterations are not able to drive a strong and specific oncogenesis. Recurrent MYC amplifications (96%) and KDR variants (8%) were detected in post-radiation angiosarcomas, in agreement with the literature. Transcriptomic analysis of such angiosarcomas revealed two distinct groups harboring different genomic imbalances (in particular gains of 17q24.2-17qter) with different clinical courses according to patient's vital status. Differential gene expression analysis permitted to focus on the immune response as a potential actor to tumor aggressiveness. Histochemistry validated a lower inflammation and lower immune infiltrate at tumor periphery for highly aggressive angiosarcomas. Our results provide new genomic and transcriptomic information about post-radiation sarcomas. The techniques we used (RNA-seq and DNA-arrays) did not highlight major differences in sarcomas with complex genetics depending on the radiation context, revealing similar patterns of transcriptomic profiles and chromosomal copy number variations. Additional characterizations, particularly whole genome sequencing, could measure changes in DNA following radiation therapy in such malignancies and may precise their oncogenesis.

Presentation and outcome of frequent and rare sarcoma histologic subtypes: A study of 10,262 patients with localized visceral/soft tissue sarcoma managed in reference centers.

BACKGROUND: The objective of this study was to describe characteristics at diagnosis and outcomes of adults with soft tissue sarcoma. METHODS: The authors conducted a retrospective multicenter study of 12,262 patients who were treated between January 1980 and 31 December 2013 in French Sarcoma Group centers and enrolled in the "Conticabase." Diagnoses were systematically reviewed by expert pathologists, and entities were classified according to the 2013 World Health Organization classification. Diagnostic characteristics, treatments, and outcomes are described for the entire cohort, for the subgroup of patients with translocation-related sarcomas, and for 9 different histologic subtypes. RESULTS: The results stressed the magnitude of heterogeneity among adult sarcomas. For example, compared with other sarcomas, translocation-related sarcomas (2143 tumors; 20.8%) were associated with a younger age at presentation (40.6 vs 60.0 years; P < .0001), a low rate of predisposing conditions (0.01% vs 22.3%; P < .0001), a higher rate of lymph node involvement (4.7% vs 1.3%; P < .0001), and a higher rate of synchronous metastasis (11.9% vs 6.7%; P < .001); and complete (R0) resection (41.6% vs 31.9%; P < .0001), receipt of (neo)adjuvant radiation therapy (62.6% vs 42.2%; P < .0001), and receipt of (neo)adjuvant chemotherapy (36.6% vs 22.3%; P < .0001) were significantly more frequent. Overall, translocation-related sarcomas were associated with a lower rate of local relapse (18.1% vs 26.0%; P < .0001) but a higher rate of metastatic relapse (42.0% vs 30.7%; P < .0001). CONCLUSIONS: Collaborative efforts are urgently needed to better assess the natural history and management options for every histologic subtype of sarcoma. Cancer 2018;124:1179-87. © 2017 American Cancer Society.

Predictive and prognostic factors associated with soft tissue sarcoma response to chemotherapy: a subgroup analysis of the European Organisation for Research and Treatment of Cancer 62012 study.

BACKGROUND: The European Organization for Research and Treatment of Cancer (EORTC) 62012 study was a Phase III trial of doxorubicin versus doxorubicin-ifosfamide chemotherapy in 455 patients with advanced soft tissue sarcoma (STS). Analysis of the main study showed that combination chemotherapy improved tumor response and progression-free survival, but differences in overall survival (OS) were not statistically significant. We analyzed factors prognostic for tumor response and OS, and assessed histological subgroup and tumor grade as predictive factors to identify patients more likely to benefit from combination chemotherapy. METHODS: Central pathology review was performed by six reference pathologists. Gender, age, performance status, time from first presentation with sarcoma to starting palliative chemotherapy, tumor grade, histological subgroup, primary tumor site involvement, and sites of metastases were assessed as prognostic factors. RESULTS: Three hundred and ten patients were included in this study. Discordance between local and central pathology opinion of tumor histology and tumor grade was observed in 98 (32%) and 122 (39%) cases, respectively. In multivariate analysis, liposarcoma patients had improved tumor response compared to other histological subgroups, whilst patients with metastases other than lung, liver or bone had a poorer response [odds ratio (OR) 0.42, 95% confidence interval (CI) 0.23-0.78; p = 0.006]. Patients with bone metastases had reduced OS [hazard ratio (HR) 1.56, 95% CI 1.16-2.09; p = 0.003]. By central pathology review, patients with undifferentiated pleomorphic sarcoma (UPS) had improved tumor response and OS with doxorubicin-ifosfamide compared to single-agent doxorubicin (OR 9.90, 95% CI 1.93-50.7 and HR 0.44, 95% CI 0.26-0.79, respectively). Grade III tumors had improved response with combination chemotherapy but there was no interaction between chemotherapy and grade on OS. CONCLUSIONS: Prospective central pathology review of tumor histology should be integrated into future STS clinical trials. Doxorubicin-ifosfamide may be most appropriate for young, fit patients with poorly differentiated Grade III tumors including UPS.

[Intra-abdominal soft tissue tumors. What needs to be known to reach the diagnosis with the help of immunohistochemistry, FISH and molecular biology]. / Tumeurs des tissus mous intra-abdominales. Ce qu'il faut savoir pour parvenir à un diagnostic en s'aidant de l'immunohistochimie, de la FISH, et de la biologie moléculaire.

Connective tissue tumors located inside the abdomen are a rare heterogeneous group of tumors, except for gastro-intestinal stromal tumors. They may be benign, malignant, or intermediate in terms of biologic potential. Pathologists have to remember the list of all the lesions possibly involved, with their immunohistochemical characteristics, and to know which molecular analyses are needed, with which expected results, and by which team they can be performed. The main tumor types are discussed with diagnostic tools and treatment consequences.

Distinct Cellular Origins and Differentiation Process Account for Distinct Oncogenic and Clinical Behaviors of Leiomyosarcomas.

In leiomyosarcoma (LMS), a very aggressive disease, a relatively transcriptionally uniform subgroup of well-differentiated tumors has been described and is associated with poor survival. The question raised how differentiation and tumor progression, two apparently antagonist processes, coexist and allow tumor malignancy. We first identified the most transcriptionally homogeneous LMS subgroup in three independent cohorts, which we named 'hLMS'. The integration of multi-omics data and functional analysis suggests that hLMS originate from vascular smooth muscle cells and show that hLMS transcriptional program reflects both modulations of smooth muscle contraction activity controlled by MYOCD/SRF regulatory network and activation of the cell cycle activity controlled by E2F/RB1 pathway. We propose that the phenotypic plasticity of vascular smooth muscle cells coupled with MYOCD/SRF pathway amplification, essential for hLMS survival, concomitant with PTEN absence and RB1 alteration, could explain how hLMS balance this uncommon interplay between differentiation and aggressiveness.

Randomized multicenter and stratified phase II study of gemcitabine alone versus gemcitabine and docetaxel in patients with metastatic or relapsed leiomyosarcomas: a Federation Nationale des Centres de Lutte Contre le Cancer (FNCLCC) French Sarcoma Group Study (TAXOGEM study).

BACKGROUND: This study aimed to evaluate the efficacy and toxicity of single-agent gemcitabine versus gemcitabine plus docetaxel as second-line therapy in patients with uterine and nonuterine leiomyosarcoma (LMS). PATIENTS AND METHODS: Patients had metastatic or unresectable LMS and had received one prior anthracycline-based regimen. A total of 90 patients received either single-agent gemcitabine (arm A; gemcitabine, 1,000 mg/m(2) i.v. for 100 minutes on days 1, 8, and 15 of a 28-day cycle) or a combination of gemcitabine and docetaxel (arm B; gemcitabine, 900 mg/m(2) i.v. for 90 minutes on days 1 and 8, plus docetaxel, 100 mg/m(2) i.v. for 1 hour on day 8 of a 21-day cycle with lenograstim). The primary endpoint was the objective response rate. RESULTS: The objective response rates were 19% and 24% in arm A (gemcitabine) and arm B (gemcitabine plus docetaxel), respectively, for patients with uterine LMS. For patients with nonuterine LMS, the objective response rates were 14% and 5% for arms A and B, respectively. The median progression-free survival times for arms A and B were 5.5 months and 4.7 months, respectively, for patients with uterine LMS. For patients with nonuterine LMS, the median progression-free survival times were 6.3 months and 3.8 months for arms A and B, respectively. One toxic death occurred in arm B. CONCLUSIONS: Both single-agent gemcitabine and gemcitabine plus docetaxel were found to be effective second-line therapies for leiomyosarcomas, with a 3-month progression-free survival rate of 40% for LMS with both uterine and nonuterine sites of origin. Single-agent gemcitabine yielded results similar to those of gemcitabine plus docetaxel in this trial, but patients using single-agent gemcitabine experienced less toxicity.

Molecular characterization by array comparative genomic hybridization and DNA sequencing of 194 desmoid tumors.

Desmoid tumors are fibroblastic/myofibroblastic proliferations. Previous studies reported that CTNNB1 mutations were detected in 84% and that mutations of the APC gene were found in several cases of sporadic desmoid tumors lacking CTNNB1 mutations. Forty tumors were analyzed by comparative genomic hybridization (CGH). Karyotype and fluorescence in situ hybridization revealed a nonrandom occurrence of trisomy 8 associated with an increased risk of recurrence. We report the first molecular characterization including a large series of patients. We performed array CGH on frozen samples of 194 tumors, and we screened for APC mutations in patients without CNNTB1 mutation. A high frequency of genomically normal tumors was observed. Four relevant and recurrent alterations (loss of 6q, loss of 5q, gain of 20q, and gain of Chromosome 8) were found in 40 out of 46 tumors with chromosomal changes. Gain of Chromosomes 8 and 20 was not associated with an increased risk of recurrence. Cases with loss of 5q had a minimal common region in 5q22.5 including the APC locus. Alterations of APC, including loss of the entire locus, and CTNNB1 mutation could explain the tumorigenesis in 89% of sporadic desmoids tumors and desmoids tumors occurring in the context of Gardner's syndrome. A better understanding of the pathogenetic pathways in the initiation and progression of desmoid tumors requires studies of 8q and 20q gains, as well as of 6q and 5q losses, and study of the Wnt/beta-catenin pathway.

Medium levels of transcription and replication related chromosomal instability are associated with poor clinical outcome.

Genomic instability (GI) influences treatment efficacy and resistance, and an accurate measure of it is lacking. Current measures of GI are based on counts of specific structural variation (SV) and mutational signatures. Here, we present a holistic approach to measuring GI based on the quantification of the steady-state equilibrium between DNA damage and repair as assessed by the residual breakpoints (BP) remaining after repair, irrespective of SV type. We use the notion of Hscore, a BP "hotspotness" magnitude scale, to measure the propensity of genomic structural or functional DNA elements to break more than expected by chance. We then derived new measures of transcription- and replication-associated GI that we call iTRAC (transcription-associated chromosomal instability index) and iRACIN (replication-associated chromosomal instability index). We show that iTRAC and iRACIN are predictive of metastatic relapse in Leiomyosarcoma (LMS) and that they may be combined to form a new classifier called MAGIC (mixed transcription- and replication-associated genomic instability classifier). MAGIC outperforms the gold standards FNCLCC and CINSARC in stratifying metastatic risk in LMS. Furthermore, iTRAC stratifies chemotherapeutic response in LMS. We finally show that this approach is applicable to other cancers.

Nationwide incidence of sarcomas and connective tissue tumors of intermediate malignancy over four years using an expert pathology review network.

BACKGROUND: Since 2010, nationwide networks of reference centers for sarcomas (RREPS/NETSARC/RESOS) collected and prospectively reviewed all cases of sarcomas and connective tumors of intermediate malignancy (TIM) in France. METHODS: The nationwide incidence of sarcoma or TIM (2013-2016) was measured using the 2013 WHO classification and confirmed by a second independent review by expert pathologists. Simple clinical characteristics, yearly variations and correlation of incidence with published clinical trials are presented and analyzed. RESULTS: Over 150 different histological subtypes are reported from the 25172 patients with sarcomas (n = 18712, 74,3%) or TIM (n = 6460, 25.7%), with n = 5838, n = 6153, n = 6654, and n = 6527 yearly cases from 2013 to 2016. Over these 4 years, the yearly incidence of sarcomas and TIM was therefore 70.7 and 24.4 respectively, with a combined incidence of 95.1/106/year, higher than previously reported. GIST, liposarcoma, leiomyosarcomas, undifferentiated sarcomas represented 13%, 13%, 11% and 11% of tumors. Only GIST, as a single entity had a yearly incidence above 10/106/year. There were respectively 30, 64 and 66 different histological subtypes of sarcomas or TIM with an incidence ranging from 10 to 1/106, 1-0.1/106, or < 0.1/106/year respectively. The 2 latter incidence groups represented 21% of the patients with 130 histotypes. Published phase III and phase II clinical trials (p<10-6) are significantly higher with sarcomas subtypes with an incidence above 1/106 per. CONCLUSIONS: This nationwide registry of sarcoma patients, with exhaustive histology review by sarcoma experts, shows that the incidence of sarcoma and TIM is higher than reported, and that tumors with a very low incidence (1<106/year) are less likely to be included in clinical trials.

Prognostic factors in early-stage leiomyosarcoma of the uterus.

Uterine leiomyosarcomas (LMSs) are rare cancers representing less than 1% of all uterine malignancies. Clinical International Federation of Gynecology and Obstetrics (FIGO) stage is the most important prognostic factor. Other significant prognostic factors, especially for early stages, are difficult to establish because most of the published studies have included localized and extra-pelvian sarcomas. The aim of our study was to search for significant prognostic factors in clinical stage I and II uterine LMS. The pathologic features of 108 uterine LMS including 72 stage I and II lesions were reviewed using standardized criteria. The prognostic significance of different pathologic features was assessed. The median follow-up in the whole group was 64 months (range, 6-223 months). The 5-year overall survival (OS) and metastasis-free interval and local relapse-free interval rates in the whole group and early-stage group (FIGO stages I and II) were 40% and 57%, 42% and 50%, 56% and 62%, respectively. Clinical FIGO stage was the most important prognostic factor for OS in the whole group (P = 4 x 10). In the stage I and II group, macroscopic circumscription was the most significant factor predicting OS (P = 0.001). In the same group, mitotic score and vascular invasion were associated with metastasis-free interval (P = 0.03 and P = 0.04, respectively). Uterine LMSs diagnosed using standardized criteria have a poor prognosis, and clinical FIGO stage is an ominous prognostic factor. In early-stage LMS, pathologic features such as mitotic score, vascular invasion, and tumor circumscription significantly impact patient outcome.

Prospective assessment of the predictive value of the BRCA1 gene status in sarcoma patients treated with trabectedin: an updated analysis of the EORTC 62091 trial.

We describe the predictive value of BRCA1 gene status on trabectedin efficacy and found no correlation despite the mechanisms of action of this drug that rely on DNA repair systems.

Dedifferentiated liposarcomas with divergent myosarcomatous differentiation developed in the internal trunk: a study of 27 cases and comparison to conventional dedifferentiated liposarcomas and leiomyosarcomas.

Dedifferentiated liposarcoma (DLPS) is one of the most frequent sarcomas of the retroperitoneum and represents most undifferentiated sarcomas of the internal trunk. In about 5% cases, the dedifferentiated component is an heterologous sarcoma such as leiomyosarcoma or rhabdomyosarcoma. We reviewed a series of 65 sarcomas with a myogenic differentiation developed in the internal trunk for which initial diagnoses were leiomyosarcoma (37), rhabdomyosarcoma (6), malignant mesenchymoma (6), and DLPS (16). Immunostainings for MDM2, CDK4, alpha smooth actin, desmin, caldesmon, myogenin, c-kit, and progesterone receptor were performed. In 48 cases, the amplification status of MDM2 and CDK4 could be evaluated with quantitative polymerase chain reaction on paraffin-embedded tissues extracted DNAs. After review of the cases, final diagnoses were leiomyosarcoma (35), rhabdomyosarcomatous (20) or leiomyosarcomatous (7) DLPS, probable DLPS (2), and malignant mesenchymoma (1). DLPS were bigger tumors (median: 18.2 cm) than leiomyosarcomas (median: 12 cm). They had a lower 5-year recurrence-free survival than leiomyosarcomas (45% vs. 71%) but a higher 5-year metastasis-free survival (73% vs. 39%). There was no significant difference in overall survival (57% vs. 34%). Outcome of patients with a DLPS with a myosarcomatous component did not differ from conventional DLPS. In conclusion, most sarcomas with a rhabdomyosarcomatous differentiation occurring in the internal trunk of adults are DLPS. Moreover, DLPS with a myogenic component have a low metastatic potential, similar to conventional DLPS and significantly lower to the metastatic potential of leiomyosarcomas.

Translocation-positive low-grade fibromyxoid sarcoma: clinicopathologic and molecular analysis of a series expanding the morphologic spectrum and suggesting potential relationship to sclerosing epithelioid fibrosarcoma: a study from the French Sarcoma Group.

Low-grade fibromyxoid sarcomas (LGFMS) bear either the t(7,16) (q32-34;p11) or t(11,16) (p11;p11) translocations, resulting in FUS-CREB3L2 or FUS-CREB3L1 fusions, respectively. Heretofore, fusion transcripts were mainly detected in frozen tissues, using reverse transcription-polymerase chain reaction. In this study, we aimed to develop a reliable method to detect these in paraffin-embedded tissues, and to examine the clinicopathologic characteristics of a series of translocation-positive LGFMS. Sixty-three neoplasms with typical morphologic features of LGFMS and 66 non-LGFMS tumors selected for their resemblance to LGFMS (LGFMS-like tumors) were examined. RNA of sufficient quality could be extracted from 111/129 (86%) cases (59 LGFMS, 52 non-LGFMS). Of all, 48/59 (sensitivity, 81%) LGFMS contained detectable transcripts (45 FUS-CREB3L2, 3 FUS-CREB3L1). Most relevant clinicopathologic features of fusion-positive LGFMS included predominance in lower extremities (22/48; thigh: 13/48), deep situation (46/48), and occasional presence of unusual histologic features, for example, hypercellular areas (16/48), foci of epithelioid cells (13/48), and giant rosettes (6/48). Most tumors expressed EMA (41/45), at least focally, CD99 (38/41) and bcl-2 (36/41) while being essentially negative for CD34 (2/45), mdm2 (1/41), smooth muscle actin (1/45), S100 protein (0/46), desmin (0/44), h-caldesmon (0/42), keratins (0/44), and CD117 (0/40). Eleven presumed LGFMS were fusion negative. Of all, 7/52 non-LGMFS neoplasms contained FUS-CREB3L2 transcripts, of which 4 had been diagnosed as sclerosing epithelioid fibrosarcoma. In conclusion, FUS-CREB3L1/L2 fusion transcripts can be detected in paraffin-embedded LGFMS in a sensitive manner, using reverse transcription-polymerase chain reaction. Most fusion-positive LGFMS are EMA-positive and CD34/S100/smooth muscle actin negative. The presence of epithelioid cells and fusion transcripts in both LGFMS and a subset of sclerosing epithelioid fibrosarcoma suggest that these neoplasms might be related.

[Plexiform schwannoma of the delto-pectoral area]. / Schwannome plexiforme profond de la région delto-pectorale gauche.

Plexiform schwannoma is a form of schwannoma which usually involves cutaneous tissues. It cannot be easily differentiated from malignant tumors, especially deep or cellular lesions. We report a deep plexiform schwannoma which we place among the various benign or malignant nerve sheath tumors, which may or may not develop within the context of genetic disease. Finally, the differential diagnoses are discussed. Recognition of the lesion is necessary for appropriate treatment.

PDL1 expression is a poor-prognosis factor in soft-tissue sarcomas.

Soft-tissue sarcomas (STS) are a group of rare, heterogeneous, and aggressive tumors, with high metastatic risk and relatively few efficient systemic therapies. In the quest for new treatments, the immune system represents an attractive therapeutic target. Recently, PD1/PDL1 inhibitors showed very promising results in patients with solid tumors. PDL1 expression has been rarely studied in STS, in small series only, by using immunohistochemistry (IHC), and with non-concordant prognostic implications. Here, we have analyzed PDL1 mRNA expression in 758 clinical STS samples retrospectively profiled using DNA microarrays and RNAseq, and searched for correlations with clinicopathological variables including metastasis-free survival (MFS) after surgery. PDL1 expression was heterogeneous across the samples. PDL1-high samples (41%) were more frequently leiomyosarcomas and liposarcomas, and showed more frequently a complex genetic profile and a high-risk CINSARC signature. No correlation existed with other clinicopathological features such as tumor site, depth, and pathological tumor grade and size. In multivariate prognostic analysis, the PDL1-high class was associated with shorter MFS, independently of the pathological type and the CINSARC signature. Analysis of correlations with biological factors suggested the existence in tumors of the PDL1-high class of a strong and efficient cytotoxic T-cell response, however associated with some degree of T-cell exhaustion and negative regulation. In conclusion, we show that PDL1 expression refines the prediction of metastatic relapse in operated localized STS, and that PD1/PDL1 blockade holds potential to improve patient survival by reactivating inhibited T cells to increase the antitumor immune in PDL1-high tumors.

Histologic grade, but not SYT-SSX fusion type, is an important prognostic factor in patients with synovial sarcoma: a multicenter, retrospective analysis.

PURPOSE: To assess the prognostic value of SYT-SSX fusion type, in comparison with other factors, in a population of 165 patients with synovial sarcoma (SS). PATIENTS AND METHODS: Data on 165 patients with SS (141 with localized disease at diagnosis) were studied retrospectively. The following parameters were examined for their potential prognostic value: age at diagnosis, sex, tumor site (extremities v proximal/truncal), size, histology, mitotic count, necrosis, histologic grade (Federation Nationale des Centres de Lutte Contre le Cancer system), stage (1997 tumor-node-metastasis system classification), surgical margin status (assessed histologically), and fusion type (SYT-SSX1 v SYT-SSX2). Median follow-up time was 37 months (range, 2 to 302 months). RESULTS: Among those patients with localized disease at diagnosis, median and 5-year disease-specific survivals (DSS) for the SYT-SSX1 and SYT-SSX2 subgroups were 126 months and 67.4% versus 82 months and 63.2%, respectively (P = .12). Median and 5-year metastasis-free survivals (MFS) were 84 months and 54.2% for SYT-SSX1 versus 50 months and 47.6% for SYT-SSX2 (P = .76). Univariate analyses showed that high histologic grade (grade 3), high mitotic count (>/= 10 mitoses/10 high-power fields), stage III disease, size greater than 7 cm, tumor necrosis, and presence of areas of poorly differentiated morphology were significant adverse prognostic factors for DSS and MFS, whereas SYT-SSX fusion type, tumor histology (biphasic v monophasic), and patient sex were not. Age greater than 35 years adversely affected DSS but not MFS. In multivariate analyses, histologic grade was the most significant prognostic factor for both DSS and MFS. CONCLUSION: For patients with localized SS, histologic grade but not SYT-SSX fusion type is a strong predictor of survival.

Changing concepts in the pathological basis of soft tissue and bone sarcoma treatment.

Though soft tissue sarcomas are rare considerable progress has been made in the clinical and biological understanding of these neoplasms. This has led to the launch of a new WHO classification of soft tissue tumours in 2002, which integrate morphological data with tumour specific (cyto-) genetics. Moreover worldwide consensus has grown how to predict clinical behaviour based on a specific grading system and which specific types of tumours seem not to obey these rules. As a consequence entry criteria for multi-institute prospective trials have changed over the last few years. The recent identification of tumour specific drug targets by immunohistochemistry has had impact on specimen requirements and handling as well as laboratory standards. These changes in concepts, classification, and processing of soft tissue sarcomas have had impact on patient selection and treatment and formats of multi-institute trials.

Dermatofibrosarcoma protuberans, giant cell fibroblastoma, and hybrid lesions in children: clinicopathologic comparative analysis of 28 cases with molecular data--a study from the French Federation of Cancer Centers Sarcoma Group.

The clinicopathologic and immunohistochemical features of 28 dermatofibrosarcoma protuberans (DFSP), giant cell fibroblastomas (GCFs), and hybrid lesions occurring in children are presented, including molecular data for seven of them. There were 19 pure adult-type DFSP (9 male and 10 female patients aged between a few days [neonate] and 13 years, median 7 years), 5 pure GCF (all males aged from 2 to 8 years, median 4 years), and 4 hybrid tumors (all males aged from 1 to 4 years, median 2.5 years). Tumor locations in pure adult-type DFSP included the trunk (6) and lower (11) and upper (2) limbs. Pure GCFs were observed on the trunk (4) and knee (1), and hybrid lesions on the trunk (2) and lower (1) and upper (1) extremities. Tumor size (n = 20) ranged from 0.6 to 5 cm (median 2 cm). Histologically, pure DFSP presented as monotonous and infiltrative, low-grade, dermal/hypodermal storiform spindle cell proliferations, sparing adnexal structures. GCF showed a dense fibrous to myxoid matrix containing slender wavy spindle cells and multinucleated giant stromal cells often lining angiectoid spaces. Hybrid lesions showed varying combinations of DFSP and GCF areas. Mitotic activity ranged from 1 to 3 mitoses per 10 high power fields. All tumors were diffusely positive for vimentin and CD34 but negative for smooth muscle actin, desmin, epithelial membrane antigen, and cytokeratins; one pure adult-type DFSP was also S-100 protein positive; <1% of nuclei were Ki67 (Mib-1) positive. One karyotyped adult-type DFSP showed an unbalanced t(17;22) (q22;q13) translocation. Multiplex RT-PCR analysis and sequencing of PCR products in seven cases showed gene fusion transcripts in two pure DFSP, two pure GCFs, and one hybrid lesion. Results were uncertain in one pure GCF; one adult-type DFSP was negative. Treatment procedures were known for 27 patients, consisting of 16 wide excisions and 11 marginal excisions. Follow-up information on 15 widely excised tumors (median 24 months; range 5-144 months) showed no recurrence. Five of six marginally excised lesions with available follow up recurred 2 months to 6 years (median 2 years) after initial surgery; all but one were cured by wide reexcision. None of the tumors metastasized. In conclusion, this study emphasizes 1) the occurrence of adult-type DFSP in children, 2) the close relationship between DFSP and GCF clinically, histologically, and molecularly, 3) the excellent prognostic of these lesions if widely excised, and 4) the diagnostic usefulness of RT-PCR analyses in detecting the gene fusion transcripts resulting from the t(17;22) (q22;q13) in paraffin-embedded tissues.

Breast carcinoma metastasis within granulosa cell tumor of the ovary: morphologic, immunohistologic, and molecular analyses of the two different tumor cell populations.

Gynecologic metastasis of breast carcinoma is not an infrequent event, but metastases within another tumor is very rare. We report a case of unilateral ovarian tumor arising in a 63-year-old woman receiving tamoxifen therapy with a past history of breast carcinoma. The microscopic appearance was principally that of a granulosa cell tumor, but the presence of atypical cells closely admixed within the classical areas was reminiscent of metastasis from breast carcinoma. The diagnosis of this first reported case of breast carcinoma metastasis within granulosa cell tumor was supported by immunohistologic analysis. The diagnosis of tumor-to-tumor metastasis was also confirmed by molecular study using microdissections of samples from the initial breast tumor and from the subsequent ovarian tumor. When compared with normal tissue, carcinomatous cells in the breast tissue exhibited genomic abnormality at the same locus as the metastatic cells in the ovary. In contrast, granulosa cell tumor areas did not show any loss of heterozygosity or instability for the microsatellites analyzed.