Disruption of the TP53 locus in osteosarcoma leads to TP53 promoter gene fusions and restoration of parts of the TP53 signalling pathway.

TP53 is the most frequently mutated gene in human cancer. This gene shows not only loss-of-function mutations but also recurrent missense mutations with gain-of-function activity. We have studied the primary bone malignancy osteosarcoma, which harbours one of the most rearranged genomes of all cancers. This is odd since it primarily affects children and adolescents who have not lived the long life thought necessary to accumulate massive numbers of mutations. In osteosarcoma, TP53 is often disrupted by structural variants. Here, we show through combined whole-genome and transcriptome analyses of 148 osteosarcomas that TP53 structural variants commonly result in loss of coding parts of the gene while simultaneously preserving and relocating the promoter region. The transferred TP53 promoter region is fused to genes previously implicated in cancer development. Paradoxically, these erroneously upregulated genes are significantly associated with the TP53 signalling pathway itself. This suggests that while the classical tumour suppressor activities of TP53 are lost, certain parts of the TP53 signalling pathway that are necessary for cancer cell survival and proliferation are retained. In line with this, our data suggest that transposition of the TP53 promoter is an early event that allows for a new normal state of genome-wide rearrangements in osteosarcoma. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Subclassification of epithelioid sarcoma with potential therapeutic impact.

Epithelioid sarcoma is a rare and aggressive mesenchymal tumour, the genetic hallmark of which is the loss of expression of SMARCB1, a key member of the SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodelling complex. Hampered by its rarity, epithelioid sarcoma has received little research attention and therapeutic options for this disease remain limited. SMARCB1-deficient tumours also include malignant rhabdoid tumour, atypical teratoid and rhabdoid tumour, epithelioid malignant peripheral nerve sheath tumour, and poorly differentiated chordoma. Histologically, it can be challenging to distinguish epithelioid sarcoma from malignant rhabdoid tumour and other SMARCB1-deficient tumours, whereas methylation profiling shows that they represent distinct entities and facilitates their classification. Methylation studies on SMARCB1-deficient tumours, although not including epithelioid sarcomas, reported methylation subgroups which resulted in new clinical stratification and therapeutic approaches. In addition, emerging evidence indicates that immunotherapy, including immune checkpoint inhibitors, represents a promising therapeutic strategy for SMARCB1-deficient tumours. Here, we show that some epithelioid sarcomas share methylation patterns of malignant rhabdoid tumours indicating that this could help to distinguish these entities and guide treatment. Using gene expression data, we also showed that the immune environment of epithelioid sarcoma is characterised by a predominance of CD8+ lymphocytes and M2 macrophages. These findings have potential implications for the management of patients with epithelioid sarcoma. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Overlapping morphological, immunohistochemical and genetic features of superficial CD34-positive fibroblastic tumor and PRDM10-rearranged soft tissue tumor.

Superficial CD34-positive fibroblastic tumor (SCD34FT) is a recently recognized soft tissue tumor that is considered to be of borderline malignancy. The pathogenesis of this tumor remains incompletely understood, but it has been suggested that SCD34FT overlaps with tumors showing fusions involving the PRDM10 gene. Previous analyses of PRDM10-rearranged tumors have demonstrated that they have a distinct gene expression profile, resulting in high expression of CADM3 (also known as SynCam3), which can be detected immunohistochemically. Here, we investigated a series (n = 43) of SCD34FT or PRDM10-rearranged tumors and potential mimics (n = 226) with regard to morphological, genetic, and immunohistochemical features. The results show that SCD34FT and PRDM10-rearranged tumor are morphologically indistinguishable; 41 of 43 tumors of both entities are CADM3-positive. Hence, we suggest that they constitute a single entity, preferably referred to as SCD34FT. Expression of CADM3 was only rarely seen in other soft tissue tumors, except in tumors with Schwann cell differentiation. Thus, IHC for CADM3, in combination with the characteristic morphological features, is a valuable adjunct in the diagnosis of SCD34FT.

Primary Angiosarcoma of the Cervix: Case Report of a Rare Lesion.

Angiosarcomas of the female genital tract are rare and primary angiosarcoma of the cervix is extremely rare with only one prior case report. We report a case of a primary cervical angiosarcoma in a 43-yr-old woman who presented with heavy vaginal bleeding. Cervical biopsy and subsequent radical hysterectomy showed a malignant vascular tumor which was composed of spindled and epithelioid cells and formed abortive vascular channels. Immunohistochemically, the tumor cells were diffusely positive for CD31, CD34, ERG, and cyclin D1 and focally positive for D2-40. A reverse transcription polymerase chain reaction test for YWHAE-NUTM2 genetic fusion was negative excluding a YWHAE-translocated high-grade endometrial stromal sarcoma. The tumor formed a 5 cm mass within the cervix with microscopic involvement of the endometrium, superficial myometrium, and vagina. Metastatic microscopic tumor deposits were present in both ovaries, left fallopian tube, one paracervical lymph node, and one pelvic lymph node. In reporting this unusual case we discuss the differential diagnosis.

FN1-EGF gene fusions are recurrent in calcifying aponeurotic fibroma.

Calcifying aponeurotic fibroma (CAF) is a soft tissue neoplasm with a predilection for the hands and feet in children and adolescents. Its molecular basis is unknown. We used chromosome banding analysis, fluorescence in situ hybridization (FISH), mRNA sequencing (RNA-seq), RT-PCR, and immunohistochemistry to characterize a series of CAFs. An insertion ins(2;4)(q35;q25q?) was identified in the index case. Fusion of the FN1 and EGF genes, mapping to the breakpoint regions on chromosomes 2 and 4, respectively, was detected by RNA-seq and confirmed by RT-PCR in the index case and two additional cases. FISH on five additional tumours identified FN1-EGF fusions in all cases. CAFs analysed by RT-PCR showed that FN1 exon 23, 27 or 42 was fused to EGF exon 17 or 19. High-level expression of the entire FN1 gene in CAF suggests that strong FN1 promoter activity drives inappropriate expression of the biologically active portion of EGF, which was detected immunohistochemically in 8/9 cases. The FN1-EGF fusion, which has not been observed in any other neoplasm, appears to be the main driver mutation in CAF. Although further functional studies are required to understand the exact pathogenesis of CAF, the composition of the chimera suggests an autocrine/paracrine mechanism of transformation. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

A Novel System for the Surgical Staging of Primary High-grade Osteosarcoma: The Birmingham Classification.

BACKGROUND: Chemotherapy response and surgical margins have been shown to be associated with the risk of local recurrence in patients with osteosarcoma. However, existing surgical staging systems fail to reflect the response to chemotherapy or define an appropriate safe metric distance from the tumor that will allow complete excision and closely predict the chance of disease recurrence. We therefore sought to review a group of patients with primary high-grade osteosarcoma treated with neoadjuvant chemotherapy and surgical resection and analyzed margins and chemotherapy response in terms of local recurrence. QUESTIONS/PURPOSES: (1) What predictor or combination of predictors available to the clinician can be assessed that more reliably predict the likelihood of local recurrence? (2) Can we determine a better predictor of local recurrence-free survival than the currently applied system of surgical margins? (3) Can we determine a better predictor of overall survival than the currently applied system of surgical margins? METHODS: This retrospective study included all patients with high-grade conventional osteosarcomas without metastasis at diagnosis treated at one center between 1997 and 2012 with preoperative chemotherapy followed by resection or amputation of the primary tumor who were younger than age 50 years with minimum 24-month followup for those still alive. A total of 389 participants matched the inclusion criteria. Univariate log-rank test and multivariate Cox analyses were undertaken to identify predictors of local recurrence-free survival (LRFS). The Birmingham classification was devised on the basis of two stems: the response to chemotherapy (good response = ≥ 90% necrosis; poor response = < 90% necrosis) and margins (< 2 mm or ≥ 2 mm). The 5-year overall survival rate was 67% (95% confidence interval [CI], 61%-71%) and 47 patients developed local recurrence (12%). RESULTS: Intralesional margins (hazard ratio [HR], 9.9; 95% CI, 1.2-82; p = 0.03 versus radical margin HR, 1) and a poor response to neoadjuvant chemotherapy (HR, 3.8; 95% CI, 1.7-8.4; p = 0.001 versus good response HR, 1) were independent risk factors for local recurrence (LR). The best predictor of LR, however, was a combination of margins ≤ 2 mm and a less than 90% necrosis response to chemotherapy (Birmingham 2b HR, 19.6; 95% CI, 2.6-144; p = 0.003 versus Birmingham 1a; margin >2 mm and more than 90% necrosis HR, 1). Two-stage Cox regression model and higher Harrell's C statistic demonstrate that the Birmingham classification was superior to the Musculoskeletal Tumor Society (MSTS) margin classification for predicting LR (Harrell's C statistic Birmingham classification 0.68, MSTS criteria 0.59). A difference in overall survival was seen between groups of the Birmingham classification (log-rank test p < 0.0001), whereas the MSTS margin system was not discriminatory (log-rank test p = 0.14). CONCLUSIONS: Based on these observations, we believe that a combination of the recording of surgical margins in millimeters and the response to neoadjuvant chemotherapy can more accurately predict the risk of local recurrence than the current MSTS system. A multicenter collaboration study initiated by the International Society of Limb Salvage is recommended to test the validity of the proposed classification and if these findings are confirmed, this classification system might be considered the standard practice in oncology centers treating patients with osteosarcomas and allow more effective communication of margin status for research. LEVEL OF EVIDENCE: Level IV, prognostic study.

Myoepithelioma of the ovary: first reported case.

A wide variety of neoplasms of varying histogenesis occur within the ovary. We report the first case of a primary ovarian myoepithelioma, a diagnosis made on the basis of the morphologic features coupled with immunoreactivity with epithelial and myoid markers. The tumor had a lobulated appearance with variable architectural patterns including anastomosing cords, trabeculae, and nests of epithelioid to spindled tumor cells within a hyalinised and focally myxoid stroma. Fluorescence in situ hybridization for EWS gene rearrangement and reverse transcriptase polymerase chain reaction for EWSR1-POU5F1 and EWSR1-PBX1, molecular abnormalities which are found in some extrasalivary myoepitheliomas, were negative. In reporting this unique neoplasm, we discuss the wide differential diagnosis generated by the case.

Small cell osteosarcoma versus fusion-driven round cell sarcomas of bone: retrospective clinical, radiological, pathological, and (epi)genetic comparison with clinical implications.

Small cell osteosarcoma (SCOS), a variant of conventional high-grade osteosarcoma (COS), may mimic fusion-driven round cell sarcomas (FDRCS) by overlapping clinico-radiological and histomorphological/immunohistochemical characteristics, hampering accurate diagnosis and consequently proper therapy. We retrospectively analyzed decalcified formalin-fixed paraffin-embedded (FFPE) samples of 18 bone tumors primarily diagnosed as SCOS by methylation profiling, fusion gene analysis, and immunohistochemistry.In eight cases, the diagnosis of SCOS was maintained, and in 10 cases it was changed into FDRCS, including three Ewing sarcomas (EWSR1::FLI1 in two cases and no identified fusion gene in the third case), two sarcomas with BCOR alterations (KMT2D::BCOR, CCNB3::BCOR, respectively), three mesenchymal chondrosarcomas (HEY1::NCOA2 in two cases and one case with insufficient RNA quality), and two sclerosing epithelioid fibrosarcomas (FUS::CREBL3 and EWSR1 rearrangement, respectively).Histologically, SCOS usually possessed more pleomorphic cells in contrast to the FDRCS showing mainly monomorphic cellular features. However, osteoid was seen in the latter tumors as well, often associated with slight pleomorphism. Also, the immunohistochemical profile (CD99, SATB2, and BCOR) overlapped.Clinically and radiologically, similarities between SCOS and FDRCS were observed, with by imaging only minimal presence or lack of (mineralized) osteoid in most of the SCOSs.In conclusion, discrimination of SCOS, epigenetically related to COS, versus FDRCS of bone can be challenging but is important due to different biology and therefore therapeutic strategies. Methylation profiling is a reliable and robust diagnostic test especially on decalcified FFPE material. Subsequent fusion gene analysis and/or use of specific immunohistochemical surrogate markers can be used to substantiate the diagnosis.

Borderline ovarian mucinous neoplasm recurring as small cell carcinoma of hypercalcemic type: evidence for an epithelial histogenesis and relationship with ovarian mucinous tumors for this enigmatic neoplasm.

Ovarian small cell carcinoma of hypercalcemic type (OSCCHT) is an uncommon neoplasm of uncertain histogenesis. As far as we are aware, this neoplasm has never been reported in association with another primary ovarian tumor. We report a case in a 33-year-old patient in whom an extraovarian pericolonic neoplasm with the morphological features and immunohistochemical profile of OSCCHT developed 5 years after removal of an ovarian mucinous borderline tumor of the intestinal type. Together with the observation that mucinous epithelium is seen in some OSCCHTs, this case raises the possibility that this enigmatic neoplasm is of epithelial origin and is related to primary ovarian mucinous neoplasms. The pericolonic tumor exhibited an unusual immunophenotype with positive staining with CD99 and FLI-1, suggesting the possibility of a neoplasm in the Ewing family of tumors. This was excluded by molecular studies that showed no evidence of EWS/FLI-1 or EWS/ERG translocation.

Synovial sarcoma of the vulva and vagina: a clinicopathologic and molecular genetic study of 4 cases.

Synovial sarcoma is a morphologically and genotypically distinctive soft tissue sarcoma with a strong predilection for young and middle aged adults and the deep soft tissues of the extremities. Rare cases of synovial sarcoma have been reported in a large variety of unusual sites, one of the least common being the female genital tract. We report 4 young women with synovial sarcoma involving the vulva (3 cases) and vagina (1 case). Two of the tumors were of the biphasic and 2 of the monophasic type; 3 of the tumors were poorly differentiated. The diagnosis in all the cases was supported by immunohistochemical findings and reverse transcription polymerase chain reaction and sequencing demonstration of SS18/SSX fusion transcripts. Two of the patients developed recurrent disease (1 dies of disease after 8 years) and 2 are currently disease-free.This study shows the importance of pathologists being aware of the rare occurrence of synovial sarcoma in the female genital tract, discusses the differential diagnosis with particular reference to this location, emphasizes the need for molecular genetic support in such cases, and reviews the sparse, earlier literature. Synovial sarcoma should be considered in the differential diagnosis of a vulvovaginal mesenchymal lesion, especially in a young female.

Stewart-Treves syndrome and the use of positron emission tomographic scanning.

In this article, we provide an account of two rare cases of Stewart-Treves syndrome, that is, cutaneous angiosarcoma secondary to lymphedema, treated at our center. Unusually, both occurred in the lower extremity. The first case was treated initially with a wide local excision, followed by a further re-excision, and eventually an above-the-knee amputation because of recurrence. In the second case, a hindquarter amputation was undertaken after a positron emission tomographic scan, which revealed the extent and spread of the lesions. In cases of cutaneous angiosarcoma, a positron emission tomographic scan can be extremely helpful in demonstrating the extent of subcutaneous spread and planning surgical management.

Miscellaneous Tumours of Bone.

There are several tumors that do not easily fit into the specific classifications of primary bone tumors. These tumors include tumors of neural, adipocytic, smooth muscle lineage, and some of uncertain lineage. The pathologic features with recent updates of these tumors are discussed here.

Sclerosing epithelioid fibrosarcoma of bone: morphological, immunophenotypical, and molecular findings of 9 cases.

Primary sclerosing epithelioid fibrosarcoma (SEF) of bone is a rare and scarcely reported neoplasm. We document clinicopathological and molecular features of 9 additional cases. Five males and 4 females had a mean age of 39 years (14-71 years). Most tumors affected flat/irregular bones; only 3 cases involved a long bone. By radiology, it has characteristic radiographic features of a predominantly lytic expansile lesion with a sclerotic rim. Referring diagnoses were SEF (n = 2), low-grade osteosarcoma (n = 2), chondrosarcoma (n = 1), and chondromyxoid fibroma (n = 1). Histologically, five cases revealed classical morphology of SEF of soft tissue. Remaining cases were classified as hybrid SEF/low-grade fibromyxoid sarcoma, characterized by spindle or stellate cells, prominent stroma, and giant hyalinized areas. Various morphological deviations such as prominent vasculature (n = 3), osteoid-like material (n = 4), or parallel bone trabeculae (n = 2) were observed. Immunohistochemically, all cases showed diffuse and strong MUC4 expression. SATB2 was observed in 5/8 cases. Using FISH, EWSR1, and FUS rearrangements were detected in 4 cases and 1 case, respectively. EWSR1-CREB3L1 fusion was identified in 1 additional case by next-generation sequencing. Recurrence and metastasis were observed in 1 case and 2 cases, respectively. All but one patient were alive with disease for a mean interval of 31 months. SEF of bone is a relatively indolent sarcoma of adults, most commonly located in the flat/irregular bones. Due to overlapping histological features, it is often misdiagnosed as osteosarcoma or a chondroid tumor. Most SEF of bone exhibit EWSR1 rearrangements, but rare cases may harbor a FUS gene fusion.

EWSR1-SMAD3-Positive Fibroblastic Tumor.

EWSR1-SMAD3-positive fibroblastic tumor is a recently characterized neoplasm with distinct clinicopathologic features and recurrent EWSR1-SMAD3 gene fusion. ESFT typically presents as a small, painless tumor in extremity subcutaneous tissues. Their behavior is benign, although they are prone to local recurrence. They typically comprise two components: intersecting fascicles of overlapping, uniform plump spindle cells, and less cellular hyalinized areas containing stippled calcifications. Immunohistochemically, the cells consistently show diffuse ERG nuclear expression, while other markers are negative. The morphology of this neoplasm can lead to histologic confusion with both benign and malignant soft tissue tumors, including monophasic synovial sarcoma, malignant peripheral nerve sheath tumor, and spindle cell sarcoma, not otherwise specified. Correct identification of ESFT is critical, most importantly to avoid unnecessary overtreatment as sarcoma.

Recurrent Fusions Between YAP1 and KMT2A in Morphologically Distinct Neoplasms Within the Spectrum of Low-grade Fibromyxoid Sarcoma and Sclerosing Epithelioid Fibrosarcoma.

Sclerosing epithelioid fibrosarcoma (SEF) is an aggressive soft tissue sarcoma. In the majority of cases, there is overexpression of MUC4, and most cases show EWSR1-CREB3L1 gene fusions. A subset of SEF displays composite histologic features of SEF and low-grade fibromyxoid sarcoma (LGFMS). These "hybrid" tumors are more likely to harbor the FUS-CREB3L2 fusion, which is also seen in most LGFMS. We, here, characterize a series of 8 soft tissue neoplasms with morphologic features highly overlapping with LGFMS and SEF but lacking MUC4 expression and EWSR1/FUS-CREB3L gene fusions. Seven tumors showed fusions of the YAP1 and KMT2A genes, and 1 had a fusion of PRRX1 and KMT2D; all but 1 case displayed reciprocal gene fusions. At gene expression profiling, YAP1 and KMT2A/PRRX1 and KMT2D tumors were distinct from LGFMS/SEF. The patients were 4 female individuals and 4 male individuals aged 11 to 91 years. Tumors with known locations were in the lower extremity (5), trunk (2), and upper extremity (1); 3 originated in acral locations. Tumor size ranged from 2.5 to 13 cm. Proportions of SEF-like and LGFMS-like areas varied considerably among tumors. All tumors that showed infiltrative growth and mitotic figures per 10 HPFs ranged from 0 to 18. Tumor necrosis was present in 1 case. Follow-up was available for 5 patients (11 to 321 mo), 2 of whom developed local recurrences, and 1 died of metastatic disease. The clinical behavior of these soft tissue sarcomas remains to be further delineated in larger series with extended follow-up; however, our limited clinical data indicate that they are potentially aggressive.

Loss of NF2 defines a genetic subgroup of non-FOS-rearranged osteoblastoma.

Osteoblastoma is a locally aggressive tumour of bone. Until recently, its underlying genetic features were largely unknown. During the past two years, reports have demonstrated that acquired structural variations affect the transcription factor FOS in a high proportion of cases. These rearrangements modify the terminal exon of the gene and are believed to stabilise both the FOS transcript and the encoded protein, resulting in high expression levels. Here, we applied in-depth genetic analyses to a series of 29 osteoblastomas, including five classified as epithelioid osteoblastoma. We found recurrent homozygous deletions of the NF2 gene in three of the five epithelioid cases and in one conventional osteoblastoma. These events were mutually exclusive from FOS mutations. Structural variations were determined by deep whole genome sequencing and the number of FOS-rearranged cases was less than previously reported (10/23, 43%). One conventional osteoblastoma displayed a novel mechanism of FOS upregulation; bringing the entire FOS gene under the control of the WNT5A enhancer that is itself activated by FOS. Taken together, we show that NF2 loss characterises a subgroup of osteoblastomas, distinct from FOS-rearranged cases. Both NF2 and FOS are involved in regulating bone homeostasis, thereby providing a mechanistic link to the excessive bone growth of osteoblastoma.

PRDM10-rearranged Soft Tissue Tumor: A Clinicopathologic Study of 9 Cases.

Gene fusion transcripts containing PRDM10 were recently identified in low-grade undifferentiated pleomorphic sarcomas (UPS). Here, we describe the morphologic and clinical features of 9 such tumors from 5 men and 4 women (age: 20 to 61 y). Three cases had previously been diagnosed as UPS, 3 as superficial CD34-positive fibroblastic tumor (SCD34FT), 2 as pleomorphic liposarcoma, and 1 as pleomorphic hyalinizing angiectatic tumor. The tumors were located in the superficial and deep soft tissues of the thigh/knee region (4 cases), shoulder (2 cases), foot, trunk, and perineum (1 case each) ranging in size from 1 to 6 cm. All showed poorly defined cellular fascicles of pleomorphic cells within a fibrous stroma with frequent myxoid change and a prominent inflammatory infiltrate. All displayed highly pleomorphic nuclear features, but a low mitotic count. Most tumors were well circumscribed. One of 9 tumors recurred locally, but none metastasized. Immunohistochemically, all were CD34 and showed nuclear positivity for PRDM10; focal positivity for cytokeratins was seen in 5/6 cases. PRDM10 immunoreactivity was evaluated in 50 soft tissue tumors that could mimic PRDM10-rearranged tumors, including 4 cases exhibiting histologic features within the spectrum of SCD34FT. Except for 2/6 pleomorphic liposarcomas and 1/4 myxofibrosarcomas, other tumors did not show nuclear positivity but displayed weak to moderate cytoplasmic immunoreactivity. In conclusion, PRDM10-rearranged soft tissue tumor is characterized by pleomorphic morphology and a low mitotic count. Its morphologic spectrum overlaps with SCD34FT. Clinical features of this small series suggest an indolent behavior, justifying its distinction from UPS and other sarcomas.

Ewing family of tumours involving the vulva and vagina: report of a series of four cases.

BACKGROUND: Ewing's sarcoma and peripheral primitive neuroectodermal tumour (pPNET) are now regarded as two morphological ends of a spectrum of neoplasms, characterised by a t(11;22) or other related chromosomal translocation involving the EWS gene on chromosome 22 and referred to as Ewing family of tumours (EFTs). EFTs are extremely rare in the vulva and vagina, a review of the literature revealing only 13 previously reported possible cases, most of which have not had molecular confirmation. In this study, four new cases of EFTs involving the vulva (three cases) or vagina (one case) are reported. RESULTS: The tumours occurred in women aged 19, 20, 30 and 40 years and ranged in size from 3 to 8 cm. Morphologically, all neoplasms had a lobulated architecture and were composed of solid aggregates of cells. In one case, occasional rosettes were formed. In all the tumours, there was diffuse membranous staining with CD99; nuclear positivity with FLI-1 was present in two cases. Three cases were focally positive with the broad-spectrum cytokeratin AE1/3, all were diffusely positive with vimentin and all were desmin negative. In two cases, a t(11;22) (q24;q12) (EWSR1-FLI-1) chromosomal translocation was demonstrated by reverse transcriptase-PCR (one case) and fluorescence in situ hybridisation (FISH) (one case), and in another case a rearrangement of the EWSR1 gene on chromosome 22 was demonstrated by FISH. In the other case, a variety of molecular studies did not reveal a translocation involving the EWS gene but this tumour, on the balance of probability, is still considered to represent a neoplasm in the EFTs. Follow-up in two cases revealed that one patient developed pulmonary metastasis and died and another is alive without disease at 12 months. CONCLUSIONS: This report expands the published literature regarding EFTs involving the vulva and vagina and stresses the importance of molecular techniques in firmly establishing the diagnosis, especially when these neoplasms arise at unusual sites.

In-depth Genetic Analysis of Sclerosing Epithelioid Fibrosarcoma Reveals Recurrent Genomic Alterations and Potential Treatment Targets.

Purpose: Sclerosing epithelioid fibrosarcoma (SEF) is a highly aggressive soft tissue sarcoma closely related to low-grade fibromyxoid sarcoma (LGFMS). Some tumors display morphologic characteristics of both SEF and LGFMS, hence they are known as hybrid SEF/LGFMS. Despite the overlap of gene fusion variants between these two tumor types, SEF is much more aggressive. The current study aimed to further characterize SEF and hybrid SEF/LGFMS genetically to better understand the role of the characteristic fusion genes and possible additional genetic alterations in tumorigenesis.Experimental Design: We performed whole-exome sequencing, SNP array analysis, RNA sequencing (RNA-seq), global gene expression analyses, and/or IHC on a series of 13 SEFs and 6 hybrid SEF/LGFMS. We also expressed the FUS-CREB3L2 and EWSR1-CREB3L1 fusion genes conditionally in a fibroblast cell line; these cells were subsequently analyzed by RNA-seq, and expression of the CD24 protein was assessed by FACS analysis.Results: The SNP array analysis detected a large number of structural aberrations in SEF and SEF/LGFMS, many of which were recurrent, notably DMD microdeletions. RNA-seq identified FUS-CREM and PAX5-CREB3L1 as alternative fusion genes in one SEF each. CD24 was strongly upregulated, presumably a direct target of the fusion proteins. This was further confirmed by the gene expression analysis and FACS analysis on Tet-On 3G cells expressing EWSR1-CREB3L1Conclusions: Although gene fusions are the primary tumorigenic events in both SEF and LGFMS, additional genomic changes explain the differences in aggressiveness and clinical outcome between the two types. CD24 and DMD constitute potential therapeutic targets. Clin Cancer Res; 23(23); 7426-34. ©2017 AACR.

Pre- and post-chemotherapy alkaline phosphatase levels as prognostic indicators in adults with localised osteosarcoma.

The prognostic value of alkaline phosphatase (AP) measured before and after chemotherapy, but before surgery was established in a retrospective survey of patients. The patients were 18 years or older, with non-metastatic high-grade osteosarcoma. Pre-chemotherapy AP was available in 89 cases, post-chemotherapy AP in 86 patients, and both in 71 cases. AP was classified as Normal (< 100% upper limit), High (100% < or = AP < 200%) or Very High (AP > or = 200%). Osteosarcoma subtype was predominantly conventional. No correlation was found between subtype and chemotherapy response, local recurrence or survival. Pre-chemotherapy AP was raised more in the osteoblastic subtype. Post-chemotherapy AP and normalisation were the same among different subtypes. AP was not correlated with local recurrence. Normal or High pre-chemotherapy AP correlated with better survival at 10 years (64% and 70%) than Very High pre-chemotherapy AP (37%, P = 0.005). Post-chemotherapy AP correlated with survival (68%, 39% and 25% in the Normal, High and Very High group, P = 0.0007) and response to chemotherapy (P = 0.049). A pre-chemotherapy AP above twice Normal correlated with worse survival. If AP decreased after chemotherapy, but was still raised, survival was better, but still worse than if AP normalised. A raised post-chemotherapy AP predicts poor chemotherapy response.