Search

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., (© 2024. The Author(s).)

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., (© 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.)

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., (© 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.)

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., (© 2021. The Author(s), under exclusive licence to United States & Canadian Academy of Pathology.)

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., (Copyright © 2021 Elsevier Inc. All rights reserved.)

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.

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.

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., (© 2020 The Authors. The Journal of Pathology: Clinical Research published by The Pathological Society of Great Britain and Ireland & John Wiley & Sons, Ltd.)

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.

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.

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.

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-CREB3L1 Conclusions: 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 ., (©2017 American Association for Cancer Research.)

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.

Background: Extra-pleural and extra-meningeal solitary fibrous tumour (SFT) is a rare sarcoma histotype curable with surgery in the majority of patients. The behaviour of these tumours ranges from indolent/very low grade to malignant/high grade but it is still not possible to accurately predict prognosis after surgery. We have investigated a multi-centre series to stratify the risk of recurrence to patients with SFTs., Methods: We retrospectively analysed the data from 243 patients who underwent surgery (2002-2011) at four sarcoma referral centres., Results: Upon univariate analysis, hypercellularity, atypia, necrosis, high mitotic rate (ie >4 mitoses/10 HPF) were associated with both disease-free and overall survival. Surgical margins were a significant prognostic factor for disease-free (P = 0.007) but not for overall survival. Unexpectedly, larger tumour size was associated with a better prognosis (P = 0.038) and fewer recurrences (P = 0.024). Upon multivariable analysis, high mitotic rate (hazard ratio, HR = 2.85, P = 0.002), cellular atypia (HR = 1.62, P = 0.015) and hypercellularity (HR = 1.82, P = 0.031) were significantly associated with recurrences. A SFT recurrence score has been provided to stratify risk of recurrence., Conclusion: This study provides a prognostic model to stratify risk of recurrence in patients with resectable SFTs. This allows clinician to decide on an optimal follow-up strategy and to select patients that may benefit from adjuvant treatments., (Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.)

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., (Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Chordomas are an aggressive rare type of malignant bone tumors arising from the remnant of the notochord. Chordomas occur mainly in vertebral bones and account for 1-4% of malignant bone tumors. Management and treatment of chordomas are difficult as they are resistant to conventional chemotherapy; therefore, they are mainly treated with surgery and radiation therapy. In this study, we performed DNA methylation profiling of 26 chordomas and normal nucleus pulposus samples plus UCH-1 chordoma cell line using the Illumina Infinium HumanMethylation450 BeadChips. Combined bisulfite restriction analysis and bisulfite sequencing was used to confirm the methylation data. Gene expression was analyzed using RT-PCR before and after 5-aza-2'-deoxycytidine (5-azaDC) treatment of chordoma cell lines. Analysis of the HumanMethylation450 BeadChip data led to the identification of 8,819 loci (2.9%) that were significantly differentially methylated (>0.2 average β-value difference) between chordomas and nucleus pulposus samples (adjusted P < 0.05). Among these, 5,868 probes (66.5%) were hypomethylated, compared to 2,951 (33.5%) loci that were hypermethylated in chordomas compared to controls. From the 2,951 differentially hypermethylated probes, 33.3% were localized in the promoter region (982 probes) and, among these, 104 probes showed cancer-specific hypermethylation. Ingenuity Pathway Analysis indicates that the cancer-specific differentially methylated loci are involved in various networks including cancer disease, nervous system development and function, cell death and survival, cellular growth, cellular development, and proliferation. Furthermore, we identified a subset of probes that were differentially methylated between recurrent and non-recurrent chordomas. BeadChip methylation data was confirmed for these genes and gene expression was shown to be upregulated in methylated chordoma cell lines after treatment with 5-azaDC. Understanding epigenetic changes in chordomas may provide insights into chordoma tumorigenesis and development of epigenetic biomarkers.

We undertook a retrospective cohort study to determine clinical outcomes following the revision of metal-on-metal (MoM) hip replacements for adverse reaction to metal debris (ARMD), and to identify predictors of time to revision and outcomes following revision. Between 1998 and 2012 a total of 64 MoM hips (mean age at revision of 57.8 years; 46 (72%) female; 46 (72%) hip resurfacings and 18 (28%) total hip replacements) were revised for ARMD at one specialist centre. At a mean follow-up of 4.5 years (1.0 to 14.6) from revision for ARMD there were 13 hips (20.3%) with post-operative complications and eight (12.5%) requiring re-revision. The Kaplan-Meier five-year survival rate for ARMD revision was 87.9% (95% confidence interval 78.9 to 98.0; 19 hips at risk). Excluding re-revisions, the median absolute Oxford hip score (OHS) following ARMD revision using the percentage method (0% best outcome and 100% worst outcome) was 18.8% (interquartile range (IQR) 7.8% to 48.3%), which is equivalent to 39/48 (IQR 24.8/48 to 44.3/48) when using the modified OHS. Histopathological response did not affect time to revision for ARMD (p = 0.334) or the subsequent risk of re-revision (p = 0.879). Similarly, the presence or absence of a contralateral MoM hip bearing did not affect time to revision for ARMD (p = 0.066) or the subsequent risk of re-revision (p = 0.178). Patients revised to MoM bearings had higher rates of re-revision (five of 16 MoM hips re-revised; p = 0.046), but those not requiring re-revision had good functional results (median absolute OHS 14.6% or 41.0/48). Short-term morbidity following revision for ARMD was comparable with previous reports. Caution should be exercised when choosing bearing surfaces for ARMD revisions., (©2014 The British Editorial Society of Bone & Joint Surgery.)

Late local recurrence is rare in conventional pelvic chondrosarcoma. Adequacy of surgical margins is an important factor of disease control and majority of local recurrences occur within 5 years of surgery. We present a case of a 43-year-old female who underwent a PII/III resection of a Grade 1 to 2 chondrosarcoma and was discharged from routine follow-up after a 10-year disease-free interval. Thirteen years after the initial excision, she re-presented with a large local recurrence requiring a hindquarter amputation. Local recurrence more than 10 years after the index operation is uncommon in pelvic chondrosarcoma. The cases mentioned in previous studies lack documentation making recommendations on the subject difficult. Routine post-operative cross-sectional imaging is essential in pelvic chondrosarcoma even when tumour-free margins are achieved as there is no adequate adjuvant therapy to deal with microscopic disease.

BCOR-CCNB3 fusion transcripts resulting from an X-chromosomal paracentric inversion were recently identified in a series of unclassifiable soft tissue and bone sarcomas with Ewing sarcoma-like morphology. The morphologic and clinical features of these sarcomas are, as yet, not well characterized. Here we describe the clinicopathologic features of 10 cases of BCOR-CCNB3 sarcoma and compare their clinical course with typical Ewing sarcoma. Nine of 10 patients were male, and all were 11 to 18 years of age. Seven tumors were located in the bone and 3 in the deep soft tissues. The histomorphologic spectrum was quite wide, with 7 tumors predominately showing small primitive cell morphology with angulated nuclei simulating so-called atypical Ewing sarcoma and 3 predominately showing spindle cell morphology. Recurrent and metastatic lesions showed increased cellularity and marked pleomorphism. Immunohistochemistry showed expression of CCNB3 (100%), bcl2 (90%), CD99 (60%), and CD117 (60%). Reverse transcription polymerase chain reaction for BCOR-CCNB3 fusion transcripts was positive in all 9 cases, which yielded sufficient extracted RNA. Five- and 10-year survival rates were 75% and 56%, respectively. BCOR-CCNB3 sarcomas located in axial skeleton and soft tissues showed a significantly shorter survival. The Ewing sarcoma overall survival was not statistically different, although there was a trend for longer survival of patients with BCOR-CCNB3 sarcomas in the extremities. In conclusion, this study provides a detailed description of the histologic spectrum, immunohistochemical features, and clinical characteristic of BCOR-CCNB3 sarcoma justifying distinction from Ewing sarcoma with its typical EWS/FUS-ETS translocations. Ideally immunohistochemistry is used in combination with reverse transcription polymerase chain reaction for definitive diagnosis.

Sclerosing epithelioid fibrosarcoma (SEF) and low-grade fibromyxoid sarcoma (LGFMS) are 2 distinct types of sarcoma, with a subset of cases showing overlapping morphologic and immunohistochemical features. LGFMS is characterized by expression of the MUC4 protein, and about 90% of cases display a distinctive FUS-CREB3L2 gene fusion. In addition, SEF is often MUC4 positive, but is genetically less well studied. Fluorescence in situ hybridization (FISH) studies have shown involvement of the FUS gene in the majority of so-called hybrid LGFMS/SEF and in 10% to 25% of sarcomas with pure SEF morphology. In this study, we investigated a series of 10 primary tumors showing pure SEF morphology, 4 cases of LGFMS that at local or distant relapse showed predominant SEF morphology, and 1 primary hybrid LGFMS/SEF. All but 1 case showed diffuse expression for MUC4. Using FISH, reverse transcription polymerase chain reaction, and/or mRNA sequencing in selected cases, we found recurrent EWSR1-CREB3L1 fusion transcripts by reverse transcription polymerase chain reaction in 3/10 pure SEF cases and splits and deletions of the EWSR1 and/or CREB3L1 genes by FISH in 6 additional cases. All 5 cases of LGFMS with progression to SEF morphology or hybrid features had FUS-CREB3L2 fusion transcripts. Our results indicate that EWSR1 and CREB3L1 rearrangements are predominant over FUS and CREB3L2 rearrangements in pure SEF, highlighting that SEF and LGFMS are different tumor types, with different impacts on patient outcome.

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.

Aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) has been used to describe the histological lesion associated with metal-on-metal (M-M) bearings. We tested the hypothesis that the lymphoid aggregates, associated with ALVAL lesions resemble tertiary lymphoid organs (TLOs). Histopathological changes were examined in the periprosthetic tissue of 62 M-M hip replacements requiring revision surgery, with particular emphasis on the characteristics and pattern of the lymphocytic infiltrate. Immunofluorescence and immunohistochemistry were used to study the classical features of TLOs in cases where large organized lymphoid follicles were present. Synchrotron X-ray fluorescence (XRF) measurements were undertaken to detect localisation of implant derived ions/particles within the samples. Based on type of lymphocytic infiltrates, three different categories were recognised; diffuse aggregates (51%), T cell aggregates (20%), and organised lymphoid aggregates (29%). Further investigation of tissues with organised lymphoid aggregates showed that these tissues recapitulate many of the features of TLOs with T cells and B cells organised into discrete areas, the presence of follicular dendritic cells, acquisition of high endothelial venule like phenotype by blood vessels, expression of lymphoid chemokines and the presence of plasma cells. Co-localisation of implant-derived metals with lymphoid aggregates was observed. These findings suggest that in addition to the well described general foreign body reaction mediated by macrophages and a T cell mediated type IV hypersensitivity response, an under-recognized immunological reaction to metal wear debris involving B cells and the formation of tertiary lymphoid organs occurs in a distinct subset of patients with M-M implants.

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare soft tissue tumor of intermediate malignancy and uncertain cellular origin and lineage of differentiation. Although PHAT is still poorly characterized at the genetic level, there is a potential genetic overlap with two other soft tissue tumors: myxoinflammatory fibroblastic sarcoma (MIFS) and hemosiderotic fibrolipomatous tumor (HFLT); MIFS and HFLT share a characteristic t(1;10)(p22;q24) with breakpoints in the TGFBR3 locus on chromosome 1 and near the MGEA5 locus on chromosome 10. Recently, a PHAT with a similar t(1;10) was reported, suggesting a genetic link between MIFS/HFLT and PHAT. To ascertain whether PHAT is also associated with this translocation, two cases were subjected to single nucleotide polymorphism (SNP) array and fluorescence in situ hybridization analyses. Neither PHAT showed a t(1;10) or other types of rearrangement of the TGFBR3 or MGEA5 loci. Both tumors showed imbalances in the SNP array analysis, but none was shared. Thus, the results indicate that PHAT is genetically distinguishable from MIFS and HFLT, but further studies are needed to identify the salient genetic pathways involved in PHAT development., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Epithelioid haemangioendothelioma (EHE), first described in 1982, is an uncommon malignancy comprising of around 1% of all vascular tumors and accurate diagnosis relies on specialist review of histology. Cervical spinal primaries are very rare and standard treatment for localised disease is surgery. Data regarding management of localized but unresectable tumors are limited. We undertook a literature review in order to highlight its clinico-pathological features and we describe a first case of an unresectable cervical EHE, successfully treated with radical radiotherapy.

Low-grade central osteosarcoma (LGCO) is a rare variant of osteosarcoma which is difficult to diagnose. If not treated appropriately, the tumour can recur with higher-grade disease. We reviewed our experience of this condition to try and identify factors that could improve both diagnosis and outcome. 18 patients out of 1540 osteosarcoma cases (over 25 years) had LGCO (1.2%). Only 11 patients (61%) were direct primary referrals. Almost 40% (7 of 18) cases were referred after treatment elsewhere when the diagnosis had not been made initially and all presented with local recurrence. Of the 11 who presented primarily, the first biopsy was diagnostic in only 6 (55%) cases. Of the remaining cases, up to three separate biopsies were required before a definitive diagnosis was made. Overall survivorship at 5 years was 90%. 17 patients were treated with limb salvage procedures, and one patient had an amputation. The diagnosis of LGCO remains challenging due to the relatively nonspecific radiological and histological findings. Since treatment of LGCO is so different to a benign lesion, accurate diagnosis is essential. Any difficult or nondiagnostic biopsies of solitary bone lesions should be referred to specialist tumour units for a second opinion.

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., (Copyright © 2011 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.)

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.

Alveolar soft part sarcoma (ASPS) is a rare malignancy; diagnostic problems may occur when cases present as a metastasis or with unusual morphologic features. In this study, a series of 18 cases with follow-up information were analysed with regard to the ASPL/TFE3 fusion transcripts and immuno-detection of TFE3 using archival formalin-fixed, paraffin-embedded tissues. Novel primers to detect ASPL/TFE3 fusion transcripts, type 1 and 2, were designed. The patients, ten female and eight male, ranged in age from 3 to 46 years; 16 involved soft tissues of the extremities (nine, lower; seven, upper), one involved the uterine cervix and one was a primary bone tumour of the foot. Seven ASPS had unusual morphologic features lacking the typical alveolar pattern. Seven had lung metastases at the time of diagnosis, and three developed lung and brain metastases later. Four patients died of disease (after 1-5 years); four are alive with metastases (after 2-15 years), and ten are alive and well (after 1-10 years). Vascular invasion correlated with metastatic disease. All 18 ASPS, four granular cell tumours (one of which was malignant) and one adrenal cortical carcinoma showed TFE3 immuno-positivity. The 18/18 ASPS showed ASPL/TFE3 fusion transcripts (nine, type 1; nine, type 2), four of which had a balanced translocation. ASPL/TFE3 fusion transcripts were not detected in 25 controls. We conclude that immuno-detection of TFE3 and RT-PCR-based identification of ASPL/TFE3 fusion transcripts in formalin-fixed, paraffin-embedded tissues are powerful tools in the diagnosis of ASPS, particularly in cases with unusual morphologic features.

Background. This study aimed to investigate prognostic factors for patients with myxoid/round-cell liposarcoma (MRCLS), in particular the significance of the round cell component, and to identify metastatic patterns as well as possibly suggest a suitable strategy for followup. Methods. Clinical, morphologic, and follow-up data from 160 patients with MRCLS was reviewed and statistically analysed. Results. Of 130 tumours with the round cell component evaluated, 61 had no round cell component, 27 had <5% round cell component, and 42 had >5%. All patients underwent surgical excision, 15 requiring amputation. 107 patients received adjuvant radiotherapy. Local recurrence occurred in 19 patients (12%), predominantly in patients with marginal or intralesional margins and a round cell component. Overall disease specific survival was 75% at 5 years and 56% at 10 years and was related to the proportion of round cell component. Of 52 patients who developed metastases, 38 (73%) had purely extrapulmonary metastases. We could not identify any factors predicting the site of metastases developing. Conclusions. The occurrence of any round cell component is the most important adverse prognostic factor for patients with MRCLS; patients with >5% round cell component are at higher risk of local recurrence, metastasis and tumour-related death and should be considered for adjuvant radiotherapy and possibly chemotherapy. The best method of monitoring extrapulmonary metastases remains to be established.

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.

Soft tissue sarcomas are relatively rare in the population, rarely encountered by the average orthopedic surgeon, and may only be seen once in a lifetime by a general practitioner. Although rare, it is a serious condition that, if diagnosed early, can result in improved prognosis. This article presents a case of a delayed diagnosis of a soft tissue sarcoma and highlights possible pitfalls and causes for such delays in hope of educating and reducing such incidences in the future.

Elastofibroma dorsi is an uncommon benign soft tissue pseudotumour usually located at the lower pole of the scapula, deep to serratus anterior, and often attached to the periosteum of the ribs, presenting with long history of swelling and occasionally pain and discomfort. This lesion is usually seen in patients over the age of 50 years and is not uncommonly mistaken as a malignant tumour because of its size and location deep to the periscapular muscles. Review of the orthopaedic oncology database of 17 500 patients revealed that there were 15 patients with elastofibroma dorsi. There were 12 males and 3 females, mean age at diagnosis of 68.4 years range 51-79 years. The diagnosis was confirmed by MRI in 3 patients, excision biopsy in 3 patients, trucut biopsy in 8 patients and open biopsy in 1 patient. Eight patients had excision of the lesion which was symptomatic. There have been no recurrences. We highlight the clinical and radiological presentation of elastofibroma dorsi to increase awareness of its existence and management.

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.

Background: Desmoid tumors have a tendency to recur locally, and traditionally they have been treated surgically. No treatment is sometimes indicated, however; this requires a morphological diagnosis that is not based on a surgical specimen. In this study we aimed to identify the diagnostic accuracy of needle and core biopsy for the morphological diagnosis of desmoid., Methods: We compared the diagnostic accuracy of fine-needle aspiration (FNA) and core needle biopsy (CNB) in 69 and 26 patients, respectively, who had had surgical resections for desmoid. We also reviewed 15 additional cases that had been incorrectly diagnosed as desmoid on FNA but which had different diagnoses after surgery., Results: FNA-based diagnoses of desmoid/fibromatosis were rendered in 35 of 69 cases, and other benign spindle cell proliferations in 26 cases and spindle cell sarcoma in the remaining 4 cases. All 26 CNBs were either suggested to correspond to desmoid (24) or other benign spindle cell lesions (2). Of the 15 FNAs incorrectly diagnosed as desmoid, 2 were found to be sarcomas., Interpretation: FNA is fairly reliable for recognition of the benign nature of desmoids. Occasional over- and under-diagnosis of malignancy can occur, however. CNB appears to be more reliable.

We report an unusual presentation of Ewing's sarcoma in an adult female who was treated for tuberculous chronic osteomyelitis before a diagnosis of Ewing's sarcoma was finally made. Emphasis is on the fact that these two conditions can masquerade each other with delays in diagnosis and possibility of devastating results.

Aims: (i) To report on the routine use of the reverse transcriptase-polymerase chain reaction (RT-PCR) technique on decalcified or non-decalcified, formalin-fixed, paraffin-embedded tissue (FFPET) for translocation detection, with particular emphasis on improved RNA extraction methodology and the use of PCR primers designed to generate small amplicons. (ii) To report on the relative incidences of translocation types and transcript variants in a large, single institution series of Ewing's sarcoma of bone., Methods and Results: Using RT-PCR to detect specific transcript variants, we analysed FFPET from 54 consecutive cases of Ewing's sarcoma of bone. We used 'gold standard' detection methods on corresponding fresh and fresh frozen tissue to validate the technique. We have demonstrated the effective use of RT-PCR on decalcified and non-decalcified FFPET samples for sarcoma-specific translocation detection (96% sensitivity, 100% specificity). Tissue decalcification did not affect the detection rate. The relative incidence of Ewing's sarcoma-specific translocation types and transcript variants was entirely consistent with previously published data., Conclusions: With equal effectiveness, RT-PCR can be applied to both acid decalcified and non-decalcified FFPET for (Ewing's sarcoma) translocation detection and the technique can be introduced into routine practice in histopathology departments.

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.

Purpose: The purpose of this case report is to bring to light this unusual combination of two rare diseases, namely Neimann-Pick disease Type B and clear cell chondrosarcoma occurring in the same patient. This has not previously been reported in the world literature., Subject: Niemann-Pick disease (NPD) is a rare autosomal recessive inborn error of metabolism. Type B NPD is even rarer. It is a lysosomal storage disorder affecting children and adolescents often causing death in early childhood, although in milder form patients may survive up to adulthood, like our patient. Clear cell chondrosarcoma is a very rare type of chondrosarcoma affecting the epiphyseo-metaphyseal region of long bones. We present a patient suffering from a milder form of Neimann Pick disease who developed a clear cell chondrosarcoma. We investigated to find if there was likely to be any relationship between these two events., Results: NPD type B is caused by a three-base deletion in chromosome 11. Chondrosarcoma and multiple exostoses occur due to loss of tumour suppressor gene EXT 2 from centromeric region on chromosome 11, though it is difficult to establish the link between the two, as the two together have not yet been reported in the literature. NPD may present diagnostic difficulties when it occurs with chondrosarcoma., Discussion: We conclude that the two diseases have not been reported together in the world literature and there is some evidence to show that chromosome 11 is central to both diseases. More research is needed to see if one leads to the other.

WT-1 positivity has previously been noted in nonneoplastic endometrial stroma. In this study we examined WT-1 expression in endometrial stromal neoplasms to ascertain whether these tumors are immunoreactive and whether this antibody might be of value in the diagnosis of these lesions. We also stained cases of cellular and highly cellular leiomyomas to investigate whether WT-1 might be of value in distinguishing these from an endometrial stromal neoplasm. We compared WT-1 staining with CD10, desmin, alpha smooth muscle actin, h-caldesmon, and AE1/3, many of these antibodies being commonly used to distinguish between an endometrial stromal and a smooth muscle phenotype. Cases of ESN (n = 5), low grade ESS (n = 14), and cellular or highly cellular leiomyoma (n = 14) were stained with the aforementioned antibodies. Cases were scored on a scale of 0 to 4+, with 4+ cases exhibiting positivity of >50% of cells. Sixteen of 19 endometrial stromal neoplasms were positive with WT-1, most (14 of 16) with 4+ positivity. Staining was nuclear (5 cases), cytoplasmic (5 cases), or combined nuclear and cytoplasmic (6 cases). All endometrial stromal neoplasms exhibited 4+ staining with CD10. Staining for alpha smooth muscle actin was present in most cases (14 of 19) and desmin and h-caldesmon were positive in a smaller number of cases (8 and 2 respectively). There was 4+ positivity with desmin in only 1 case. The 2 cases that were h-caldesmon positive both exhibited 1+ staining (<5% cells positive). Six cases were positive with AE1/3, 1 with 4+ staining. Leiomyomatous neoplasms always exhibited 4+ staining with desmin and alpha smooth muscle actin and in most cases (12 of 14) with h-caldesmon. The other 2 cases exhibited 2+ positivity. Most cases (12 of 14) were positive with WT-1 (7 of 14 with 4+ staining) and CD10 (5 of 14 with 4+ positivity). One case was positive with AE1/3. We conclude that diffuse WT-1 positivity is characteristic of endometrial stromal neoplasms and that this may be of value in diagnosis. However, WT-1 is of limited use in the distinction between an endometrial stromal and a cellular leiomyomatous neoplasm because many of the latter are also positive. This study confirms the value of h-caldesmon in the distinction between an endometrial stromal neoplasm (almost always h-caldesmon negative) and a cellular leiomyomatous neoplasm (h-caldesmon positive). Although CD10 is positive in endometrial stromal neoplasms, the commonly observed immunoreactivity of cellular and highly cellular leiomyomas with this antibody limits its diagnostic usefulness. Desmin is useful as all leiomyomatous neoplasms exhibited diffuse positivity, whereas only a small number of endometrial stromal neoplasms were focally positive and only 1 case exhibited 4+ positivity. Smooth muscle actin is of limited value since most neoplasms studied were positive. The overlapping immunophenotype of endometrial stromal and leiomyomatous neoplasms may reflect the origin of both cell types from a common progenitor within the uterus.

Uterine serous carcinoma (USC) is the prototype of type II endometrial cancer. Endometrial intraepithelial carcinoma (EIC) is the precursor lesion of USC, Rarely, USC and EIC may arise within and be largely confined to otherwise benign endometrial polyps. This report describes 5 such cases. The patients ranged in age from 67 to 89 years, with a mean age of 75 years. In 2 of the cases there was a history of tamoxifen therapy. In 2 cases USC or EIC was confined to the endometrial polyp, and in 3 cases there was focal involvement of nonpolypoid endometrium. In 1 case there was a single small focus of extrauterine tumor within an ovarian vascular channel. In 2 cases the invasive tumor within the polyp also contained areas of endometrioid adenocarcinoma, and in 2 cases there was a component of clear cell carcinoma. In all cases USC and EIC were strongly reactive for p53 and showed a high proliferation index with MIB1. Two cases were negative with estrogen receptor, and 3 cases exhibited positive staining. The cases reported herein show that USC and EIC may rarely arise in benign endometrial polyps and that extrauterine involvement may be present without myometrial infiltration. Because 2 of the patients had been taking tamoxifen, this raises the possibility of an association between tamoxifen and the development of USC and EIC in the endometrial polyps that are characteristic of this medication.

Müllerian carcinosarcomas occurring outside the female genital tract are extremely rare but occasionally they may arise from the peritoneum as part of the secondary müllerian system. This report describes two cases of extragenital müllerian carcinosarcoma with heterologous elements in the form of malignant cartilage. We wish to highlight the fact that these aggressive neoplasms may occasionally have a peritoneal origin, similar to primary peritoneal serous carcinomas.

Aims: Recent studies have shown that CD10 is a useful immunohistochemical marker of normal endometrial stroma and of endometrial stromal neoplasms. The aim of this study was to investigate whether CD10 immunoreactivity is present in ectopic endometrial stroma and whether staining is of value in confirming a diagnosis of endometriosis., Methods/results: Twenty five cases of endometriosis were stained with a commercially available antibody against CD10. Endometrial stromal cells were positive in 22 of 25 cases. There was little or no staining of other tissues., Conclusions: CD10 immunoreactivity is largely maintained in endometrial stromal cells located outside the uterus. Immunohistochemical staining with CD10 may be of value in confirming a diagnosis of endometriosis when there is morphological doubt.

The histological distinction between a primary endometrial and a primary endocervical adenocarcinoma is often difficult, especially in small biopsy specimens. A preoperative distinction is important because primary surgical management differs between the two tumors. Cases of primary endometrioid endometrial (n=30) and primary endocervical (n=26) adenocarcinoma of endocervical type were stained immunohistochemically with the monoclonal antibodies against carcinoembryonic antigen (CEA), vimentin, estrogen receptor (ER), and 34 beta E12. In all cases the origin of the adenocarcinoma was confirmed by examination of the definitive pathology specimen. There was diffuse positive nuclear staining for ER in 28 of 30 (93%) endometrial adenocarcinomas. ER was negative in 16 of 26 endocervical adenocarcinomas, and there was focal weak nuclear staining in the other cases. Vimentin was positive in 29 of 30 (97%) endometrial adenocarcinomas but in only 2 of 26 (8%) endocervical adenocarcinomas. CEA was positive in 25 of 26 (96%) endocervical adenocarcinomas, mostly with diffuse membranous and cytoplasmic staining. Positivity with CEA was present in 21 of 30 (70%) endometrial adenocarcinomas but was largely confined to squamoid areas with only 12 tumors exhibiting focal membranous staining of the glandular component. 34 beta E12 was diffusely positive in all except one cervical adenocarcinoma. In endometrial carcinomas, positivity was strongest in squamoid areas but there was positive staining, either focally or diffusely, of the glandular component in 27 cases. In summary, primary endometrioid endometrial adenocarcinomas are characterized by diffuse, strong, positive staining for vimentin and ER and negative or very focal, positive staining of the glandular component for CEA. In contrast, primary endocervical adenocarcinomas are characterized by CEA positivity, which is usually but not always diffuse, negativity for vimentin, and negativity or focal weak positivity for ER. 34 beta E12 is of no value in the distinction between endometrial and endocervical adenocarcinomas. A panel of immunohistochemical stains, comprising CEA, vimentin, and ER, generally allows confident preoperative distinction between a primary endometrial and endocervical adenocarcinoma.

Aims: The CD10 antigen is expressed in acute lymphoblastic leukaemia and follicle centre cell lymphoma. A recent study investigating the expression of CD10 in a wide range of non-haematopoietic neoplasms found positive staining in a small number of endometrial stromal sarcomas as well as in normal endometrial stroma. The present study aimed to ascertain whether CD10 positivity is indeed found in normal endometrial stroma and endometrial stromal neoplasms. Staining of a range of tumours which can be confused morphologically with endometrial stromal neoplasms was also undertaken to ascertain whether antibodies against CD10 are of value in a diagnostic sense., Methods and Results: Neoplasms included in the study were endometrial stromal nodule (n=1), low-grade endometrial stromal sarcoma (ESS) (n=13), high-grade ESS (n=6), mixed endometrial stromal-smooth muscle tumour (n=1), uterine cellular leiomyoma (n=10), uterine leiomyosarcoma (n=5), adult granulosa cell tumour (AGCT) (n=10), undifferentiated endometrial carcinoma (n=6), uterine carcinosarcoma with an endometrial stromal component (n=1) and type II uterine mesenchymal tumour with sex cord-like elements (n=1). Cases of proliferative (n=5), secretory (n=5) and atrophic (n=3) endometrium were also stained. There was positive staining of stroma but not of glands in all cases of non-tumorous endometrium. There was positive staining of the endometrial stromal nodule and of all low-grade ESS. Staining in these varied but was often diffuse and of moderate to strong intensity. There was positive staining of four of six high-grade ESS, but this was usually focal. There was also positive staining of the endometrial stromal component in the mixed endometrial stromal-smooth muscle tumour and in the uterine carcinosarcoma. Most cellular leiomyomas were completely negative although three exhibited weak positivity. There was some positivity, usually focal or weak, of three of five leiomyosarcomas. Most AGCT and undifferentiated carcinomas were completely negative although one case of each exhibited focal staining. There was focal staining of the type II uterine mesenchymal tumour with sex cord-like elements., Conclusion: CD10 is a reliable and sensitive immunohistochemical marker of normal endometrial stroma. Positivity, which is often strong and/or diffuse is found in endometrial stromal nodules and low-grade ESS. Positive staining with CD10, when strong and diffuse, may be useful in distinguishing these tumours from histological mimics, especially cellular leiomyoma and AGCT which are generally negative. In this situation, CD10 should be used as part of a panel which might include desmin and alpha-inhibin depending on the differential diagnosis considered. Positive staining with CD10 in a high-grade uterine sarcoma which is negative with muscle markers might indicate endometrial stromal differentiation and identify a group of neoplasms which it is correct to diagnose as high-grade ESS rather than undifferentiated uterine sarcoma.