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 tissue

Detection of the synovial sarcoma translocation t(X;18) (SYT;SSX) in paraffin-embedded tissues using reverse transcriptase-polymerase chain reaction: a reliable and powerful diagnostic tool for pathologists. A molecular analysis of 221 mesenchymal tumors fixed in different fixatives

Synovial sarcoma (SS) is a relatively rare sarcoma, which may be confused with several other mesenchymal and nonmesenchymal lesions. It bears the t(X;18) (SYT;SSX) translocation, which seems to be specific for this tumor type and can be detected in paraffin-embedded tissue, using reverse transcriptase-polymerase chain reaction (RT-PCR). However, the specificity and sensitivity of this detection method have rarely been examined in a large series. Using RT-PCR, we examined 250 mesenchymal and nonmesenchymal, benign and malignant, paraffin-embedded lesions for the SS t(X;18) (SYT-SSX) translocation. PCR products were obtained from 221 tumors (88.5%). There were 135 non-SS tumors, 22 biphasic, and 64 monophasic spindle/round cell SS, of which 10 were cytogenetically confirmed as t(X;18)-positive. SYT-SSX gene fusion transcripts were detected in the SS tumor category only (100% specificity), including 100% of the biphasic SS and 86% of monophasic spindle/round cell SS. Nine tumors originally diagnosed as SS were t(X;18) (SYT-SSX)-negative. Following reassessment, only 3 of these tumors showed clinicopathologic, immunohistochemical, and/or ultrastructural features consistent with that diagnosis, thus raising the overall detection sensitivity to 96%. With regard to the potential adverse effect of the fixatives used, PCR products were obtained in 100%, 91.5%, 90.5%, and 0% of tumors fixed with AFA, buffered formalin, Holland Bouin, and conventional Bouin's fluid, respectively. This study shows that the detection of the SS t(X;18) (SYT-SSX) in paraffin-embedded tissue is feasible with a 100% specificity and an overall 96% sensitivity, provided non-Bouin's fluid fixation is use

Activity and safety of afatinib in a window preoperative EORTC study in patients with squamous cell carcinoma of the head and neck (SCCHN)

Background: To investigate the activity and safety of afatinib in the preoperative treatment of squamous cell carcinoma of the head and neck (SCCHN). Patients and methods: This study was an open-label, randomized, multicenter, phase II window of opportunity trial. Treatment-naïve SCCHN patients selected for primary curative surgery were randomized (5: 1 ratio) to receive afatinib during 14 days (day -15 until day -1) before surgery (day 0) or no treatment. Tumor biopsies, 2-[fluorine-18]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET), and magnetic resonance imaging (MRI) were carried out at diagnosis and just before surgery. The primary end point was metabolic FDG-PET response (according to EORTC guidelines). Other end points included response assessment based on the Response Evaluation Criteria In Solid Tumors (RECIST) v1.1, dynamic contrast-enhanced (DCE)-MRI, diffusion weighted (DW)-MRI, safety, and translational research (TR). Results: Thirty patients were randomized: 25 to afatinib and 5 to control arm. Of the 23 eligible patients randomized to afatinib, 16 (70%; 95% CI: 47% to 87%) patients had a partial metabolic FDG-PET response (PMR). Five patients (22%; 95% CI: 8% to 44%) showed a partial response by RECISTv1.1. Responses assessed via DCE-MRI and DWI-MRI did not show a strong association with PMR or RECIST. One patient discontinued afatinib after 11 days for grade 3 diarrhea with subsequent renal failure and 24 days delay in surgery. No grade 4 toxicities or surgical comorbidities related to afatinib were reported. TR results indicated that PMR was more frequent in the tumors with high Cluster3-hypoxia score expression and with TP53 wild type. Conclusion: Afatinib given for 2 weeks to newly diagnosed SCCHN patients induces a high rate of FDG-PET partial metabolic response and partial response according to RECISTv1.1. Afatinib can be safely administered before surgery. Although exploratory, the hypoxic gene signature needs further investigations as a predictive biomarker of afatinib activity