Reconstruction options in recurrent dermatofibrosarcoma protuberans:A scoping review

Background

This review will outline the evaluation, diagnosis, and management of dermatofibrosarcoma protuberans and emphasizes multidisciplinary role of nurses, plastic surgeons and radiation oncologist in this recurrent metastatic lesion. It pinpoints affected population at risk, clinical features, and reconstruction options. No analytical research has been done in this area.

Material and Methods

A scoping review of patients of DFSP who underwent reconstruction after excision of tumors was performed in the Department of Burn and Plastic Surgery, AIIMS Rishikesh. It used a five framework approach. A review of 85 similar cases reported in the literature have been scrutinized in relation to the reconstruction options, sites of the tumor, margins of excision and recurrence.

Results

85 full length English studies were included out of the 445 cases found in Pubmed and related search engines to reveal various reconstructive options in reconstruction of DFSP defects. Present scoping review identifies free anterolateral thigh flap to be useful in 7 review articles followed by propeller flaps in 3 isolated case reports. 2 cases of free latissimus dorsi flap were used for reconstruction of abdominal defects.

Conclusion

All patients should undergo a strict screening protocol where the health personnel can play a crucial role by educating parents on the follow up and report new lesions as early as possible. All operated tumor patients can be given safety tips and education on care and risks after reconstruction with skin flaps or skin grafting. A multidisciplinary approach between the surgeon, nurse and radiation oncologist is needed for effective management of these lesions.

Regorafenib for the Treatment of Sarcoma

OPINION STATEMENT

Sarcomas are a rare group of tumors with many subtypes, conventionally classified into soft-tissue sarcomas and bone sarcomas. Chemotherapeutic regimens form the mainstay of systemic therapy but are not well defined beyond the first-line setting and clinical outcomes are variable. Tyrosine kinase inhibitors (TKIs), with a broad inhibition profile which have been shown to target tumor angiogenesis, have an established role in the treatment of sarcomas without characteristic driver alterations. One such TKI, regorafenib, has been evaluated in sarcomas and clinical data are discussed in this review. An overview of regorafenib data from five phase 2 and one phase 1b clinical trials in over 10 sarcoma subtypes (both soft-tissue and bone) in adult and pediatric patients is reviewed. Regorafenib demonstrated clinical benefit in patients with non-adipocytic soft-tissue sarcomas, osteosarcoma and Ewing sarcoma who had progressed on prior therapy. Patients with otherwise limited treatment options may therefore benefit from regorafenib therapy.

Evolution of Dermatofibrosarcoma Protuberans to DFSP-Derived Fibrosarcoma: An Event Marked by Epithelial-Mesenchymal Transition-like Process and 22q Loss

Dermatofibrosarcoma protuberans (DFSP) is a rare and indolent cutaneous sarcoma. At times, a fibrosarcomatous transformation marked by a more aggressive clinical behavior may be present. We investigated the natural history and the molecular bases of progression from classic DFSP to the fibrosarcomatous form (FS-DFSP), looking, retrospectively, at the outcome of all patients affected by primary DFSP treated at our institution from 1993 to 2012 and analyzing the molecular profile of 5 DFSPs and 5 FS-DFSPs by an integrated genomics approach (whole transcriptome sequencing, copy number analysis, FISH, qRT-PCR, IHC). The presence of fibrosarcomatous features was identified in 20 (7.6%) patients out of 263 DFSP. All cases were treated with macroscopic complete surgery. A local relapse occurred in 4 of 23 patients who received a microscopic marginal surgery (2 classic DFSP, 2 FS-DFSP), while metastasis affected 2 patients, both FS-DFSP (10% of FS-DFSP), being the first event. DFSP evolution to FS-DFSP was paralleled by a transcriptional reprogramming. The recurrent loss of chromosome 22q appeared to contribute to this phenomenon by promoting the expression of epigenetic regulators, such as EZH2. Loss of the p16/CDKN2A/INK4A locus at 9p was also observed in two FS-DFSP metastatic cases.

IMPLICATIONS

FS-DFSP is a rare subgroup among DFSP, with a 10% metastatic risk, that was independent from local recurrence and that was not observed in DFSP, that were all cured by wide surgery. Chromosome 22q deletion might play a role in FS-DFSP, and p16 loss may convey a poor outcome. EZH2 dysregulation was also found and represents a druggable target. Mol Cancer Res; 14(9); 820-9. ©2016 AACR.

Dermatofibrosarcoma protuberans (DFSP) successfully treated with sorafenib: case report

DFSP is a locally invasive, slow-growing tumor of the subcutaneous tissue that rarely metastasizes but recurs frequently after surgical excision. We report herein a case of highly recurrent, locally invasive DFSP that failed both postoperative radiation therapy and complete trial of Imatinib, but was successfully treated with Sorafenib, which showed unprecedented response.

Cytogenetics and molecular genetics of myxoid soft-tissue sarcomas

Myxoid soft-tissue sarcomas represent a heterogeneous group of mesenchymal tumors characterized by a predominantly myxoid matrix, including myxoid liposarcoma (MLS), low-grade fibromyxoid sarcoma (LGFMS), extraskeletal myxoid chondrosarcoma (EMC), myxofibrosarcoma, myxoinflammatory fibroblastic sarcoma (MIFS), and myxoid dermatofibrosarcoma protuberans (DFSP). Cytogenetic and molecular genetic analyses have shown that many of these sarcomas are characterized by recurrent chromosomal translocations resulting in highly specific fusion genes (e.g., FUS-DDIT3 in MLS, FUS-CREB3L2 in LGFMS, EWSR1-NR4A3 in EMC, and COL1A1-PDGFB in myxoid DFSP). Moreover, recent molecular analysis has demonstrated a translocation t(1; 10)(p22; q24) resulting in transcriptional upregulation of FGF8 and NPM3 in MIFS. Most recently, the presence of TGFBR3 and MGEA5 rearrangements has been identified in a subset of MIFS. These genetic alterations can be utilized as an adjunct in diagnostically challenging cases. In contrast, most myxofibrosarcomas have complex karyotypes lacking specific genetic alterations. This paper focuses on the cytogenetic and molecular genetic findings of myxoid soft-tissue sarcomas as well as their clinicopathological characteristics.

Establishment of a new human osteosarcoma cell line, UTOS-1: cytogenetic characterization by array comparative genomic hybridization

The cytogenetic characteristics of osteosarcoma (OS) remain controversial. The establishment of a new human OS cell line may improve the characterization. We report the establishment of a new human osteosarcoma cell line, UTOS-1, from a typical osteoblastic OS of an 18-year-old man. Cultured UTOS-1 cells are spindle-shaped, and have been maintained in vitro for over 50 passages in more than 2 years. Xenografted UTOS-1 cells exhibit features typical of OS, such as production of osteoid or immature bone matrix, and proliferation potency in vivo. UTOS-1 also exhibit morphological and immunohistochemical characteristics typical of osteoblastic OS. Chromosomal analysis by G-band show 73~85 chromosomes with complicated translocations. Array CGH show frequent gains at locus DAB2 at chromosome 5q13, CCND2 at 12p13, MDM2 at 12q14.3-q15, FLI and TOP3A at 17p11.2-p12 and OCRL1 at Xq25, and show frequent losses at HTR1B at 6q13, D6S268 at 6q16.3-q21, SHGC17327 at 18ptel, and STK6 at 20q13.2-q13.3. The UTOS-1 cell line may prove useful for biologic and molecular pathogenetic investigations of human OS.

Establishment and characterization of three new human breast cancer cell lines derived from Chinese breast cancer tissues

BACKGROUND

Breast cancer is a major malignancy affecting females worldwide. It is the most common cause of death from cancer in women. Cell lines are widely used in laboratory research and particularly as in vitro models in cancer research. But we found that the routinely used breast cancer cell lines were mostly derived from Caucasians or African-Americans. There were few standard models to study the pathogenic mechanism at molecular level and cell signaling pathway of breast cancer for Asian patients. It is quite necessary to establish new breast cancer cell lines from xanthoderm to study the pathogenic mechanism and therapeutic methods.

RESULTS

Three new breast cancer cell lines, designated BC-019, BC-020 and BC-021, were successfully established and characterized from breast invasive ductal carcinoma tissues of three Chinese female patients. These new cell lines growing as adherent monolayer with characteristic epithelial morphology could be maintained continuously in vitro, and they were ER-, PR- and C-erbB-2-positive. Their chromosomes showed high hyperdiploidy and complex rearrangements, and they displayed aggressive tumorigencity in tumorigenesis test.

CONCLUSION

The three newly established breast cancer cell lines from Chinese patients were tested for a number of, and the results indicate that the cell lines were in good quality and could be served as new cell models in breast cancer study.

Congenital atrophic dermatofibrosarcoma protuberans in a 7-month-old boy treated with Mohs micrographic surgery

Dermatofibrosarcoma protuberans is a rare, malignant, slow-growing, locally invasive tumor of the skin. Although most cases are acquired and diagnosed in adulthood, there have been an increasing number of congenital dermatofibrosarcoma protuberans mimicking benign birthmarks described in the literature. The clinical presentation of this tumor is often one of an indurated exophytic plaque or nodule; however, a rare variant can present as atrophic or sclerotic in nature. We report a case of congenital atrophic dermatofibrosarcoma protuberans of the groin in a 7-month-old boy, successfully treated with Mohs micrographic surgery.

Clinical, cytogenetic and molecular characteristics of 14 T-ALL patients carrying the TCRβ-HOXA rearrangement: a study of the Groupe Francophone de Cytogénétique Hématologique

Recently, we and others described a new chromosomal rearrangement, that is, inv(7)(p15q34) and t(7;7)(p15;q34) involving the T-cell receptor beta (TCRbeta) (7q34) and the HOXA gene locus (7p15) in 5% of T-cell acute lymphoblastic leukemia (T-ALL) patients leading to transcriptional activation of especially HOXA10. To further address the clinical, immunophenotypical and molecular genetic findings of this chromosomal aberration, we studied 330 additional T-ALLs. This revealed TCRbeta-HOXA rearrangements in five additional patients, which brings the total to 14 cases in 424 patients (3.3%). Real-time quantitative PCR analysis for HOXA10 gene expression was performed in 170 T-ALL patients and detected HOXA10 overexpression in 25.2% of cases including all the cases with a TCRbeta-HOXA rearrangement (8.2%). In contrast, expression of the short HOXA10 transcript, HOXA10b, was almost exclusively found in the TCRbeta-HOXA rearranged cases, suggesting a specific role for the HOXA10b short transcript in TCRbeta-HOXA-mediated oncogenesis. Other molecular and/or cytogenetic aberrations frequently found in subtypes of T-ALL (SIL-TAL1, CALM-AF10, HOX11, HOX11L2) were not detected in the TCRbeta-HOXA rearranged cases except for deletion 9p21 and NOTCH1 activating mutations, which were present in 64 and 67%, respectively. In conclusion, this study defines TCRbeta-HOXA rearranged T-ALLs as a distinct cytogenetic subgroup by clinical, immunophenotypical and molecular genetic characteristics.

COL1A1-PDGFB fusion in a pediatric Bednar tumor with 2 copies of a der(22)t(17;22)

We present a 10-year-old girl with a pure Bednar tumor (pigmented dermatofibrosarcoma protuberans) of the right shoulder. Cytogenetic analysis demonstrated 47 chromosomes with 2 copies of a derivative chromosome 22, der(22)t(17;22)(q22;q13). Fluorescence in situ hybridization (FISH) analysis demonstrated the COL1A1-PDGFB fusion on both der(22) chromosomes. By RT-PCR and sequencing, we observed a fusion of the COL1A1 exon 41 with PDGFB exon 2. This pure pediatric Bednar tumor in a child, like childhood dermatofibrosarcoma protuberans, had a linear structural abnormality rather than a ring chromosome that is more commonly encountered in adult Bednar and dermatofibrosarcoma protuberans tumors. The underlying molecular abnormality in this pediatric Bednar tumor is the same as in dermatofibrosarcoma protuberans.

Low-grade sarcomas with CD34-positive fibroblasts and low-grade myofibroblastic sarcomas

A subset of low-grade fibrosarcomas is composed of CD34-positive spindle cells. These include dermatofibrosarcoma, its morphologic variants, and its associated fibrosarcoma, solitary fibrous tumor, hemangiopericytoma and their malignant counterparts, and some cases of myxoinflammatory fibroblastic sarcoma. Dermatofibrosarcoma and related lesions are characterized by a t(17;22)(q22;q13) rearrangement resulting in fusion of the genes COL1A (17q21-22) and PDGFB1 (22q13). Solitary fibrous tumor displays varying cellularity and fibrosis and a peripheral hemangiopericytomatous pattern; most tumors formerly called hemangiopericytoma are now subsumed into the category of solitary fibrous tumor, although a few strictly defined examples are recognized; however, these are probably not composed of pericytes. Myofibroblastic malignancies are best identified by electron microscopy, with which varying degrees of differentiation, including the presence of fibronexus junctions, can be identified. Low-grade sarcomas showing myofibroblastic differentiation include myofibrosarcomas and inflammatory myofibroblastic tumors. Myofibrosarcomas are spindle cell neoplasms that occur in children or adults in the head and neck, trunk, and extremities as infiltrative neoplasms and that display a fascicular or fasciitis-like pattern with focal nuclear atypia and variable expression of myoid antigens. These sarcomas are prone to recurrence and a small number metastasize. Inflammatory myofibroblastic tumor (synonymous with inflammatory fibrosarcoma) is a neoplasm arising predominantly in childhood, and frequently in intraabdominal locations. It has spindle cells in fascicular, fasciitis-like and sclerosing patterns, with heavy chronic inflammation including abundant plasma cells. Many IMT have clonal chromosomal abnormalities involving 2p22-24, and fusion of the ALK gene with tropomyosin 3 (TPM3-ALK) or tropomyosin 4 (TPM4-ALK) is found in a subset.

Atrophic dermatofibrosarcoma protuberans: case report, review, and proposed molecular mechanisms

We report a case of atrophic dermatofibrosarcoma protuberans, an uncommon clinical variant. We discuss molecular and genetic mechanisms of dermatofibrosarcoma protuberans tumorigenesis, review the literature on atrophic dermatofibrosarcoma protuberans, and pose a molecular mechanism for the atrophic variant's phenotype. We also describe using Mohs micrographic excision with CD34 immunostains on the frozen sections to definitively treat the tumor.

Establishment of a new human malignant fibrous histiocytoma cell line, FU-MFH-1: cytogenetic characterization by comparative genomic hybridization and fluorescence in situ hybridization

Although a number of malignant fibrous histiocytoma (MFH) cell lines have been reported, their characterization at a molecular cytogenetic level has not been fully established. In this study, we established a new human cell line, designated as FU-MFH-1, from a storiform-pleomorphic MFH arising in the retroperitoneum of a 61-year-old woman, and applied comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH) with chromosome painting probes for the characterization of chromosome alterations. FU-MFH-1 cells were spindle, round, or polygonal in shape with oval nuclei, and were maintained continuously in vitro for over 50 passages for more than 12 months. G-banding analysis was performed and FU-MFH-1 revealed a complex karyotype with an abnormal chromosome 19 containing a homogeneously staining region (hsr). CGH analysis showed a high-level amplification of 12q13-->q21. The high-level amplification detected by CGH was refined by FISH. These results showed that the hsr was composed of amplified DNA sequences from 12q. Our study emphasizes the usefulness of CGH as a powerful tool for chromosomal localization of amplified sequences. The FU-MFH-1 cell line should be useful for biologic and molecular pathogenetic investigations of human MFH.

Genetics of dermatofibrosarcoma protuberans family of tumors: from ring chromosomes to tyrosine kinase inhibitor treatment

Dermatofibrosarcoma protuberans (DP) is a rare, slow-growing, infiltrating dermal neoplasm of intermediate malignancy, made up of spindle-shaped tumor cells often positive for CD34. The preferred treatment is wide surgical excision with pathologically negative margins. At the cytogenetic level, DP cells are characterized by either supernumerary ring chromosomes, which have been shown by using fluorescence in situ hybridization techniques to be derived from chromosome 22 and to contain low-level amplified sequences from 17q22-qter and 22q10-q13.1, or t(17;22), that are most often unbalanced. Both the rings and linear der(22) contain a specific fusion of COL1A1 with PDGFB. Similar to other tumors, the COL1A1-PDGFB fusion is occasionally cryptic, associated with complex chromosomal rearrangements. Although rings have been mainly observed in adults, translocations have been reported in all pediatric cases. DP is therefore a unique example of a tumor in which (i) the same molecular event occurs either on rings or linear translocation derivatives, (ii) the chromosomal abnormalities display an age-related pattern, and (iii) the presence of the specific fusion gene is associated with the gain of chromosomal segments, probably taking advantage of gene dosage effects. In all DP cases that underwent molecular investigations, the breakpoint localization in PDGFB was found to be remarkably constant, placing exon 2 under the control of the COL1A1 promoter. In contrast, the COL1A1 breakpoint was found to be variably located within the exons of the alpha-helical coding region (exons 6-49). No preferential COL1A1 breakpoint and no correlation between the breakpoint location and the age of the patient or any clinical or histological particularity have been described. The COL1A1-PDGFB fusion is detectable by multiplex RT-PCR with a combination of forward primers designed from a variety of COL1A1 exons and one reverse primer from PDGFB exon 2. Recent studies have determined the molecular identity of "classical" DP, giant cell fibroblastoma, Bednar tumor, adult superficial fibrosarcoma, and the granular cell variant of DP. In approximately 8% of DP cases, the COL1A1-PDGFB fusion is not found, suggesting that genes other than COL1A1 or PDGFB might be involved in a subset of cases. It has been proposed that PDGFB acts as a mitogen in DP cells by autocrine stimulation of the PDGF receptor. It is encouraging that inhibitory effects of the PDGF receptor tyrosine kinase antagonist imatinib mesylate have been demonstrated in vivo; such targeted therapies might be warranted in the near future for treatment of the few DP cases not manageable by surgery.

Pediatric pigmented dermatofibrosarcoma protuberans (Bednár tumor): case report and review of the literature with emphasis on the differential diagnosis

Dermatofibrosarcoma protuberans (DFSP) is a fibrous tumor of intermediate malignant potential that usually affects the trunk of young to middle-aged adults. On histological examination, it is characterized by a monomorphous population of spindle cells arranged in a storiform or cartwheel pattern. Bednár tumor (BT), formerly known as storiform pigmented neurofibroma, is currently considered the pigmented variant of DFSP due to the histological and cytogenetic similarities between these two lesions. There are very few reports on BT affecting pediatric patients. We describe a case of BT affecting the dorsal aspect of the left forearm of a 6-year-old-male patient and emphasize the diagnostic clues to distinguish this unusual cutaneous neoplasm from other pigmented lesions, including pigmented (melanotic) neurofibroma (PMN), psammomatous melanotic schwannoma (PMS), neurocristic cutaneous hamartoma (NCH), and desmoplastic malignant melanoma (DMM). We would like to stress that surgical pathologists and dermatopathologists need to be aware of the prototypical histological appearance of BT as there is the risk of misdiagnosing it either as pigmented tumors associated with neurocutaneous syndromes, such as PMN and PMS, or as a highly malignant melanocytic neoplasm (DMM).

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.

Establishment and characterization of a novel human desmoplastic small round cell tumor cell line, JN-DSRCT-1

The exact nature of the desmoplastic small round cell tumor (DSRCT) remains controversial. More detailed analyses might be facilitated by the establishment of permanent DSRCT cell lines. To date, however, no human DSRCT cell line has been reported. In this study, we report the establishment of a new human cell line, JN-DSRCT-1, from the pleural effusion of a 7-year-old boy with pulmonary metastasis from a typical intra-abdominal DSRCT. JN-DSRCT-1 cells were small round or spindle shaped with oval nuclei and have been maintained continuously in vitro for over 190 passages during more than 40 months. Histologic features of the heterotransplanted tumors in severe combined immunodeficiency mouse were essentially the same as those of the original DSRCT, revealing nests or clusters of small round cells embedded in an abundant desmoplastic stroma. Both in vitro and in vivo, the cells exhibited immunopositive reactions for vimentin, desmin, cytokeratins (AE1/AE3 and CAM 5.2), epithelial membrane antigen, neuron-specific antigen, and CD57 (Leu-7). JN-DSRCT-1 cells exhibited a pathognomonic t(11;22)(p13;q12) translocation by cytogenetic analysis. In addition, RT-PCR and sequencing analysis revealed a chimeric transcriptional message of the Ewing's sarcoma gene exon 10 fused to the Wilms' tumor gene exon 8. To our knowledge, this is the first permanent human DSRCT cell line. The JN-DSRCT-1 cell line, which exhibits the unique morphologic and genetic characteristics of DSRCT, will be extremely useful for a variety of important studies such as the pathogenic mechanism, biologic behavior, and therapeutic model of human DSRCT.

Synovial sarcoma with a secondary chromosome change der(22)t(17;22)(q12;q12)

A consistent, pathognomonic translocation, most commonly a balanced reciprocal translocation, t(X;18) (p11.2;q11.2), is found in more than 90% of synovial sarcomas. We report here a secondary chromosome change, der(22)t(17;22)(q12;q12), in addition to the primary t(X;18)(p11.2;q11.2) in a biphasic synovial sarcoma that occurred in the thigh of a 34-year-old woman. Although the karyotype of the primary tumor exhibited 46,X,t(X;18)(p11.2;q11.2), the recurrent tumor showed 46,X,der(X)t(X;18)(p11.2;q11.2),der(22) t(17;22)(q12;q12). The SYT-SSX1 fusion transcript was demonstrated in the primary and recurrent tumors using a reverse transcriptase polymerase chain reaction (RT-PCR). Southern blot analysis also confirmed that the detected messages were derived from the SYT-SSX fusion gene. However, we could not detect the EWS-E1AF fusion gene that has been reported to be generated through a t(17;22)(q12;q12) by RT-PCR. Furthermore, fluorescence in situ hybridization (FISH) with cosmid probes corresponding to loci flanking the EWSR1 region demonstrated no split of chromosome 22 in all analyzed interphase nuclei. To our knowledge, this is the first reported case of synovial sarcoma in which an additional (secondary) chromosome change, der(22)t(17;22)(q12;q12), has been demonstrated.

COL1A1-PDGFB gene fusion demonstrates a common histogenetic origin for dermatofibrosarcoma protuberans and its granular cell variant

Granular cell variant of dermatofibrosarcoma protuberans is very rare with only one report of two cases. We report a new case in which we demonstrated the presence of the dermatofibrosarcoma protuberans-specific COL1A1-PDGFB fusion from paraffin-embedded tissue. This case analysis demonstrated the utility of molecular genetics as a powerful tool for the diagnosis of atypical forms of dermatofibrosarcoma protuberans.

Fusion of COL1A1 exon 29 with PDGFB exon 2 in a der(22)t(17;22) in a pediatric giant cell fibroblastoma with a pigmented Bednar tumor component. Evidence for age-related chromosomal pattern in dermatofibrosarcoma protuberans and related tumors

In contrast with classic dermatofibrosarcoma protuberans (DP), genetic information about the juvenile or pigmented variant forms of DP, so-called giant cell fibroblastoma (GCF) and Bednar tumor (BT), is limited. In the sole karyotyped case of BT a supernumerary ring containing chromosomes 17 and 22 sequences, similar to DP rings, was reported, whereas in three GCF cases, t(17;22) or der(22)t(17;22) with COL1A1-PDGFB fusion involving exons 11, 40, and 47, respectively, have been described. Here, we report the first cytogenetic and molecular analysis of a tumor from a 5-year-old child that contained both GCF and BT components. The karyotype and molecular analyses confirmed the common histogenetic origin between DP, GCF, and BT in showing the presence of a der(22)t(17;22) fusing the COL1A1 exon 29 to PDGFB exon 2. Because COL1A1 exon 29 has been involved previously in gene fusion with PDGFB exon 2 in several cases of adult or infantile DP presenting either t(17;22) or ring chromosomes, our results support the concept that DP, GCF, and BT are morphologic variants of a same entity, rather than distinct tumors. Of interest, our findings give prominence to the relation between patient age and the chromosomal rearrangement pattern in DP and related tumors. Whereas only a few adult DP cases presented with translocations, all the infantile cases, either DP, GCF, or mixed BT-GCF, as shown here, contained translocation derivatives but not ring chromosomes. All the ring chromosomes were observed in adult cases. With respect to cytogenetic studies, DP, GCF, and BT appear to be a unique model for age-related chromosomal rearrangement progression.