Expression of ERG, an Ets family transcription factor, distinguishes cutaneous angiosarcoma from histological mimics

Molecular and immune pathobiology of human angiosarcoma

Angiosarcoma is a rare endothelial-derived malignancy that is extremely diverse in anatomy, aetiology, molecular and immune characteristics. While novel therapeutic approaches incorporating targeted agents and immunotherapy have yielded significant improvements in patient outcomes across several cancers, their impact on angiosarcoma remains modest. Contributed by its heterogeneous nature, there is currently a lack of novel drug targets in this disease entity and no reliable biomarkers that predict response to conventional treatment. This review aims to examine the molecular and immune landscape of angiosarcoma in association with its aetiology, anatomical sites, prognosis and therapeutic options. We summarise current efforts to characterise angiosarcoma subtypes based on molecular and immune profiling. Finally, we highlight promising technologies such as single-cell spatial "omics" that may further our understanding of angiosarcoma and propose strategies that can be similarly applied for the study of other rare cancers.

Pseudolymphomatous Cutaneous Angiosarcoma Presenting With Persistent Firm Facial Edema in a Patient With Systemic Sclerosis

ABSTRACT

Pseudolymphomatous cutaneous angiosarcoma (cAS) is a rare subtype characterized by a prominent lymphocytic infiltrate, posing diagnostic challenges due to its resemblance to lymphoid neoplastic processes. We present a novel case highlighting the clinical and histopathological features, notably its association with persistent firm facial edema in a patient with systemic sclerosis (SSc). A 47-year-old woman with a 21-year history of SSc presented with firm palpebral edema evolving to involve the entire face and cervical region over six months. Diagnostic imaging revealed inflammatory changes in orbital regions, supradiaphragmatic lymphadenopathies, and lytic lesions. Skin biopsy demonstrated a diffuse neoplasm with vascular channels and solid areas, accompanied by dense lymphocytic proliferation. Pseudolymphomatous cutaneous angiosarcoma, a rare malignant neoplasm, exhibits variable clinical presentations and rapid progression. Histologically, it manifests as irregularly shaped vascular channels lined by prominent endothelial cells. Immunohistochemistry, particularly markers such as v-ets erythroblastosis virus E26 oncogene homolog (avian) (ERG), aids in diagnosis. Notably, this case marks the first presentation of cAS with persistent facial edema in SSc, highlighting the association between SSc and cancer risk. This case underscores the diagnostic challenges posed by cAS and emphasizes the importance of early detection for optimal patient outcomes. Further understanding of its association with autoimmune disorders such as SSc is crucial for comprehensive management strategies.

Primary breast angiosarcoma: A case report

RATIONALE

Primary breast angiosarcoma is a rare tumor, accounting for only 0.05% of all malignant breast tumors. The primary breast angiosarcoma typically presents with nonspecific clinical manifestations, which can easily lead to misdiagnosis. Potential factors contributing to misdiagnosis include skin changes that may be erroneously attributed to breast trauma-induced bruising and breast swelling that may be mistaken for inflammatory diseases or other benign tumors.

PATIENT CONCERNS

A 19-year-old female was admitted to the hospital due to repeated lump formation in the left breast for 9 months after left breast trauma.

DIAGNOSES

The diagnosis of primary breast angiosarcoma was confirmed on hematoma biopsy.

INTERVENTIONS

Due to the patient's condition, no special treatment was given postoperatively. After then, there was a recurrence in the chest wall, and the patient received 2 cycles of chemotherapy, resulting in a reduction in the size and lightening of the recurrent chest wall mass. When chemotherapy intolerance happened, the patient chose to discontinue treatment.

OUTCOMES

After an 18-month follow-up, the recurrent chest wall mass increased and the patient died from bleeding.

LESSONS

Primary breast angiosarcoma has a low incidence but high malignancy, with a high recurrence and metastasis rate, leading to a poor prognosis. The adjuvant chemotherapy, radiotherapy, targeted therapy, and other treatments should be considered to reduce the local recurrence rate and prolong patient survival.

A case of primary breast angiosarcoma diagnosed by multimodal ultrasound imaging with literature review

Primary Breast Angiosarcoma (PBA) is an exceptionally rare form of breast cancer, accounting for less than 0.05% of all breast cancers. It is characterized by a high level of malignancy, invasiveness, and has a prognosis that is typically poor. The lack of distinctive clinical features makes it prone to underdiagnosis and misdiagnosis. This study retrospectively examines a case utilizing multimodal ultrasound imaging techniques (including 2D ultrasound, contrast-enhanced ultrasound, and ultrasound elastography) for diagnosing PBA. Furthermore, the study reviews relevant literature to summarize the ultrasound characteristics of PBA, with the aim of improving understanding of this elusive condition.

Characterisation of new in vitro models and identification of potentially active drugs in angiosarcoma

Angiosarcoma is a rare soft tissue sarcoma originating from endothelial cells. Given that current treatments for advanced disease have shown limited efficacy, alternative therapies need to be identified. In rare diseases, patient-derived cell models are crucial for screening anti-tumour activity. In this study, cell line models were characterised in 2D and 3D cultures. The cell lines' growth, migration and invasion capabilities were explored, confirming them as useful tools for preclinical angiosarcoma studies. By screening a drug library, we identified potentially effective compounds: 8-amino adenosine impacted cell growth and inhibited migration and invasion at considerably low concentrations as a single agent. No synergistic effect was detected when combining with paclitaxel, gemcitabine or doxorubicin. These results suggest that this compound could be a potentially useful drug in the treatment of AGS.

Angiosarcoma of the breast: A review

Breast angiosarcoma is a rare and highly aggressive malignancy with a poor prognosis. It can occur spontaneously or be associated with factors such as radiation therapy or chronic lymphedema. The etiology and pathogenesis of this disease are still unclear, the clinical symptoms and imaging findings lack specificity, and the pathological morphology is diverse, which is easy to be confused with other diseases. There is no clear guideline for surgical treatment. Although the optimal surgical approach remains unclear, the ultimate goal is surgical excision with optimal margins, which remains the primary method of treatment. In clinical practice, the choice of the surgical approach should be made by considering the tumor size, pathological type, and patient preferences. In clinical practice, the selection of surgical methods should be carried out with comprehensive consideration of tumor size, pathological types and patients' wishes. There is no clear consensus on whether radiotherapy and chemotherapy should be carried out after surgery, and its optimal program and efficacy are uncertain. This article reviews the etiology, clinical manifestations, pathological features, imaging findings, treatment, prognosis and other aspects of breast angiosarcoma, so as to strengthen clinicians' overall understanding of this disease and avoid missed diagnosis and misdiagnosis.

Chalazion-mimicked eyelid angiosarcoma in a young Asian with good prognosis: a case report

BACKGROUND

Angiosarcoma is an extremely rare malignant tumor. So far, only about 42 cases of angiosarcoma involving the eyelids have been reported. Eyelid angiosarcoma occurs more frequently in elderly Caucasian males and is prone to misdiagnosis. We present a case report in a young Asian male patient with eyelid angiosarcoma that was misdiagnosed as a chalazion.

CASE PRESENTATION

A 46-year-old South Korean male with no underlying disease had a right lower lid mass. The lesion was initially misdiagnosed as a chalazion at a local clinic, but a diagnosis of eyelid angiosarcoma was made after the first biopsy trial. PET-CT was performed to ensure that there was no metastasis in the whole body. Surgical excision with enough surgical margin was used alone for treatment and reconstruction was performed with a tarsoconjunctival advancement flap (modified Hughes procedure), which helped ensure good cosmesis. No recurrence was observed 4 years and 5 months after the surgery.

CONCLUSIONS

The current study presents the first case of chalazion-mimicked eyelid angiosarcoma in a young Asian male aged under 50 years. This case shows that even if a benign eyelid disease is suspected in a young patient, an incisional biopsy must be performed to confirm whether the lesion is malignant. Since the prognosis is good for the case of eyelid angiosarcoma, if there is no clear evidence of distal metastasis, surgical resection should be performed with an enough safety margin.

Dedifferentiated and undifferentiated melanomas: a practical approach to a challenging diagnosis

Dedifferentiation, defined as the loss of cellular features of terminal differentiation resulting in a more primitive, unspecialized phenotype, is a rare phenomenon in melanoma and more commonly observed in the metastatic setting than in primary melanomas. The diagnosis of dedifferentiated melanoma poses a significant challenge, and the tumors need to be carefully sampled and worked up to identify any residual morphologic, immunohistochemical, or molecular evidence of their melanocytic lineage. This article reviews our current knowledge of the clinical, histopathological, immunohistochemical, and molecular features of these rare tumors and provides a practical diagnostic approach and discussion of the relevant differential diagnoses and associated diagnostic pitfalls.

Cadmium, von Willebrand factor and vascular aging

Vascular aging is a major contributing factor to cardiovascular disease. The aged blood vessels, characterized by vascular wall thickening and stiffening, are instigated by endothelial cell dysfunction induced by oxidative stress and inflammation. von Willebrand Factor (vWF) is a glycoprotein known for its role in coagulation, and plasma levels of vWF are increased with age. Elevated vWF promotes thrombosis, atherosclerotic plaque formation, inflammation and proliferation of vascular smooth muscle cells. Cadmium (Cd) is an environmental pollutant associated with increased morbidity and mortality of cardiovascular disease. At low concentrations, Cd activates pro-survival signaling in endothelial cells, however enhances intima-media thickness and atherogenesis. A non-cytotoxic dose of Cd also increases endothelial vWF expression and secretion in vivo and in vitro. In this review, we summarize the molecular mechanisms underlying vWF-promoted vascular aging-associated pathologies and Cd-induced vWF expression. In addition, we propose that exposure to low-dose Cd is a risk factor for vascular aging, through elevation of plasma vWF.

Primary angiosarcoma of breast: A case report and literature review

INTRODUCTION AND IMPORTANCE

Primary angiosarcoma of breast (PAB)³ is a rare and aggressive malignancy with limited published literature. This article aims to disclose the diagnosis and treatment of this case, review previous case reports, and provide clinical experience to breast surgeons.

CASE PRESENTATION

A 36-year-old Asian female presented with a diffuse mass growing rapidly in her left breast. The ultrasonography (USG)⁴ suspected granulomatous mastitis. The core needle biopsy (CNB)⁵ confirmed the diagnosis of breast angiosarcoma (AS).⁶ She underwent mastectomy without axillary lymph node dissection (ALND)⁷ followed by adjuvant chemotherapy. About 11 months after mastectomy, the patient had bone metastasis.

CLINICAL DISCUSSION

PAB is a rare vascular neoplasia, characterized by aggressive patterns, poor prognosis, and high malignant potential. It is difficult to diagnose or differentiate only by clinical or imaging examination. Biopsy and immunohistochemical staining are the most reliable method. Mastectomy is the most common treatment.

CONCLUSION

PAB is a rare and malignant cancer. We should pay attention to the diffuse progressive masses in the breast of young female, and perform MRI and biopsy if necessary. Mastectomy is the only treatment known that has proven to benefit these patients. There are no evidence-based guidelines regarding treatment.

Angiosarcoma of the breast with hypofibrinogenemia: A rare case report and review of the literature

BACKGROUND

Breast angiosarcoma is a rare malignant tumor, accounting for approximately 0.04% of all breast malignancies. Angiosarcoma of the breast with hypofibrinogenemia is even rarer and has not been described in man. Breast angiosarcoma is associated with high metastatic potential and poor prognosis, and there is no specific manifestation in imaging. At present, surgery is considered to be the only effective treatment. There is no unified standard for postoperative adjuvant radiotherapy and chemotherapy.

CASE PRESENTATION

A 30-year-old female patient underwent left breast mass resection under local anesthesia on May 22, 2014. Postoperative pathology showed a vasogenic tumor. On November 10, 2017, she visited us again due to left breast swelling and pain during lactation, and underwent breast mass puncture. She was diagnosed with breast hematoma and fibrinogen reduction. On November 14, 2017, mastectomy was performed under tracheal intubation and general anesthesia, and the fibrinogen gradually returned to normal after surgery. Pathological examination showed a hemangiosarcoma with hematoma formation in the left breast. According to the pathological findings and after comprehensive evaluation, the patient underwent modified radical mastectomy for left breast cancer and right axillary sentinel lymph node biopsy on December 5, 2017. The patient died on January 28, 2018 due to rupture and hemorrhage of liver cancer and hemorrhagic shock.

CONCLUSION

Breast angiosarcoma with hypofibrinogenemia is a rare and highly aggressive malignancy. Clinicians should be familiar with its clinicopathological features and diagnostic criteria. Multidisciplinary approach is recommended to benefit the patients.

ERG Immunoreactivity in Blastic Hematolymphoid Neoplasms: Diagnostic Pitfall in the Workup of Undifferentiated Malignant Neoplasms

Undifferentiated malignant neoplasms pose diagnostic challenges, and reliable immunohistochemical markers with well-characterized staining profiles are desirable when characterizing them. Our initial observation of erythroblast transformation specific regulated gene-1 (ERG) reactivity in myeloid sarcomas led us to broadly explore the utility of ERG as a marker of immature hematolymphoid neoplasms presenting in extramedullary sites. We stained 207 immature and mature hematolymphoid lesions as well as 39 benign hematolymphoid tissues and found weak-to-moderate ERG immunopositivity in 15 of 16 (94%) acute myeloid leukemias/myeloid sarcomas, including 4 of 5 (80%) CD34-negative/CD117-negative acute myeloid leukemias/myeloid sarcomas. ERG positivity was also seen in all 9 cases of B-lymphoblastic and T-lymphoblastic leukemia/lymphoma, all 3 cases of hematogone hyperplasia, and all 4 cases of systemic mastocytosis. ERG was negative in 148 mature B-cell and T-cell lymphomas, including 2 high-grade B-cell lymphomas and 2 blastoid variant mantle cell lymphomas; 23 histiocytic/dendritic cell neoplasms; 2 indolent T-lymphoblastic proliferations; and 2 blastic plasmacytoid dendritic cell neoplasms. We conclude that ERG immunoreactivity may pose a significant diagnostic pitfall in the workup of undifferentiated malignant neoplasms, particularly those presenting in extramedullary sites.

The Management and Prognosis of Facial and Scalp Angiosarcoma: A Retrospective Analysis of 15 Patients

BACKGROUND

Angiosarcomas are extremely aggressive malignant tumors that arise from vascular endothelial cells. The risk factors, etiology, prognostic factors, and optimal management strategies for angiosarcomas are as yet unknown.

METHODS

We retrospectively analyzed data from 15 patients who were treated in Asan Medical Center, Seoul, Republic of Korea, in the past 12 years, to assess the effect of different treatment modalities and reconstructive methods on the locoregional recurrence, metastasis, and overall survival.

RESULTS

A total of 15 patients were identified (median age at diagnosis, 72 years; range, 61-82 years). Median tumor size was 6 cm. Median follow-up was 287 days. The median overall survival was 14.96 months; a total of 13 (87%) patients had died by the end of the study.The median locoregional recurrence, metastasis, and overall survival were 7.3, 6.5, and 16.7 months, respectively. On univariate analysis, the use of adjuvant therapy after surgery (vs surgery without adjuvant therapy) was associated with delayed median time to detection of recurrence (7.9 months vs 3.1 months, respectively; P = 0.825), delayed median time to metastasis (8.7 months vs 3.1 months, respectively; P = 0.191), and better median overall survival (7.3 months vs 3.1 months, respectively; P = 0.078).The use of flap versus skin graft as a reconstructive method was associated with delayed median recurrence (8.75 vs 7.32 months, respectively; P = 0.274) and earlier median metastasis (3.75 vs 6.53 months, respectively; P = 0.365), but the same median overall survival of 16.7 months (P value: 0.945) and tumor smaller or bigger than 5 cm show earlier median time to detection of recurrence (4.17-7.32 months; P = 0.41), earlier median time to metastasis (3.75-6.53 months; P = 0.651), but better median overall survival of 18.21 versus 16.7 months, respectively (P = 0.111).

CONCLUSIONS

Multimodal treatment that combines surgery with adjuvant therapy is the best management strategy that influences survival positively in patients with angiosarcoma. The study shows that the reconstructive method does not affect the prognosis in these patients. So it is better to choose the simplest suitable resection and reconstructive method with the least complications and to avoid unnecessary procedures.

Primary and secondary cutaneous angiosarcoma: Distinctive clinical, pathological and molecular features

Angiosarcomas are ubiquitous neoplasms involving both cutaneous and soft tissue and visceral locations. Accumulating biomolecular evidences suggest that cutaneous angiosarcomas are distinctive entities with molecular, clinical and pathological peculiarities. Despite several ongoing clinical trials with promising therapeutic agents, the prognosis of cutaneous angiosarcomas is dismal and survival still rely on early diagnosis and surgery. An accurate diagnosis and the knowledge of the underlying molecular landscape are therefore essential to improve the prognosis. We detail the molecular, clinical, dermoscopic, morphological and prognostic features of cutaneous angiosarcoma. Although the molecular landscape of cutaneous angiosarcoma is not completely understood, accumulating evidences suggest that there are characteristic molecular alterations including dysregulation of angiogenesis and several complex molecular pathways. Secondary cutaneous angiosarcomas, arising in correlation with chronic lymphedema and ionizing radiation, have different molecular hallmarks, which are also leading to the first diagnostic applications. The diagnosis of cutaneous angiosarcoma may be challenging, as well-differentiated forms can be hard to distinguish from benign and low-grade vascular neoplasms, while poorly differentiated forms can be easily confounded with other non-vascular high-grade neoplasms. An accurate and early diagnosis, which is mandatory to ensure the best survival for the patients, is mainly based on morphological hallmarks.

Histologic and Immunopathologic Variability in Primary Intraoral Angiosarcoma: A Case Report and Review of the Literature

Primary intraoral angiosarcoma is an exceptionally rare malignancy of vascular origin which can be challenging to diagnose due to microscopic and immunohistochemical variability. A histopathologically challenging case of primary intraoral angiosarcoma, occurring in a pediatric patient is presented. A comprehensive review of the literature reveals that primary intraoral angiosarcomas occur with nearly equal frequency in males and females, affect the gingiva and the tongue most commonly and are treated primarily with surgery. As with angiosarcoma in other sites, primary intraoral angiosarcoma behaves aggressively with the majority of patients succumbing to their disease.

Soft Tissue Special Issue: Cutaneous Pleomorphic Spindle Cell Tumors

This manuscript provides an overview of pleomorphic spindle cell tumors presenting on sun-damaged skin of the elderly and includes discussions of atypical fibroxanthoma, pleomorphic dermal sarcoma, spindle cell and metaplastic squamous cell carcinoma, spindle cell and dedifferentiated melanoma and poorly differentiated cutaneous angiosarcoma. These tumors share many of the clinical presenting and histological features, making confident diagnosis challenging. A reliable and robust diagnosis is necessary to predict behavior as the biologic potential of these tumors ranges from benign (e.g. atypical fibroxanthoma) to outright malignant with poor survival rates (e.g. cutaneous angiosarcoma). The salient clinical, histologic and immunohistochemical characteristics are discussed in detail with emphasis on distinguishing features and differential diagnosis to provide the reader with a better understanding of these entities and helpful clues for a more robust diagnosis.

Cutaneous angiosarcoma: a current update

Cutaneous angiosarcoma (cAS) is a rare malignant neoplasm with variable clinical presentation. Although a distinct vascular tumour, cAS shares many overlapping histopathological features with other vasoformative and epithelioid tumours or 'mimickers'. cAS shows aggressive behaviour and carries a grave prognosis, thus early diagnosis is of paramount importance to achieve the best possible outcomes. Recently, several genetic studies were conducted leading to the identification of novel molecular targets in the treatment of cAS. Herein, we present a comprehensive review of cAS with discussion of its clinical, histopathological and molecular aspects, the differential diagnosis, as well as current therapies including ongoing clinical trials.

Application of Immunohistochemistry in Undifferentiated Neoplasms: A Practical Approach

Context.—

Advances in interventional technology have enhanced the ability to safely sample deep-seated suspicious lesions by fine-needle aspiration procedures. These procedures often yield scant amounts of diagnostic material, yet there is an increasing demand for the performance of more ancillary tests, especially immunohistochemistry and, not infrequently, molecular assays, to increase diagnostic sensitivity and specificity. A systematic approach to conserving diagnostic material is the key, and our previously proposed algorithm can be applied aptly in this context.

Objective.—

To elaborate a simple stepwise approach to the evaluation of cytology fine-needle aspiration specimens and small biopsy tissue specimens, illustrating the algorithmic application of small panels of immunohistochemical stains in providing an accurate diagnosis with scant amounts of tissue, including the potential pitfalls that may arise while using immunohistochemical staining on small quantities of tissue.

Data Sources.—

The sources include literature (PubMed), the first Chinese American Pathologists Association Diagnostic Pathology Course material, and the review authors' research data as well as practice experience. Seven examples selected from the CoPath database at Geisinger Medical Center (Danville, Pennsylvania) are illustrated.

Conclusions.—

A stepwise approach to the evaluation of fine-needle aspiration and small biopsy tissue specimens in conjunction with a small panel of select immunohistochemical stains has been successful in accurately assessing the lineage/origin of the metastatic tumors of unknown primaries. The awareness of the common pitfalls of these biomarkers is essential in many instances.

Lentivirus vectors construction of SiRNA targeting interference GPC3 gene and its biological effects on liver cancer cell lines Huh-7

OBJECTIVES

To build GPC3 gene short hairpin interference RNA (shRNA) slow virus vector, observe expression of Huh-7 GPC3 gene in human liver cell line proliferation apoptosis and the effect of GPC3 gene influencing on liver cancer cell growth, and provide theoretical basis for gene therapy of liver cancer.

METHODS

Hepatocellular carcinoma cell line Huh-7 was transfected by a RNA interference technique. GPC3 gene expression in a variety of liver cancer cell lines was detected by fluorescence quantitative PCR. Targeted GPC3 gene sequences of small interfering RNA (siRNA) PGC-shRNA-GPC3 were restructured. Stable expression cell lines of siRNA were screened and established with the help of liposomes (lipofectamine(TM2000)) as carrier transfection of human liver cell lines. In order to validate siRNA interference efficiency, GPC3 siRNA mRNA expression was detected after transfection by using RT-PCR and Western blot. The absorbance value of the cells of blank group, untransfection group and transfection group, the cell cycle and cell apoptosis were calculated, and effects of GPC3 gene on Huh-7 cell proliferation and apoptosis were observed.

RESULTS

In the liver cancer cell lines Huh-7, GPC3 gene showed high expression. PGC-shRNA-GPC3 recombinant plasmid was constructed successfully via sequencing validation. Stable recombinant plasmid transfected into liver cancer cell lines Huh-7 can obviously inhibit GPC3 mRNA expression level.

CONCLUSIONS

The targeted GPC3 siRNA can effectively inhibit the expression of GPC3.

An update on the application of newly described immunohistochemical markers in soft tissue pathology

CONTEXT

During the last 5 to 10 years, significant progress has been made in the molecular characterization of soft tissue tumors, predominantly with the identification of recurrent translocations or amplification of certain genes in different tumor types. Alongside this, translational efforts have identified many novel and diagnostically useful immunohistochemical markers for many of these tumor types.

OBJECTIVE

This article reviews a select group of recently described immunohistochemical markers of particular use in the evaluation of mesenchymal neoplasms; the underlying biology of the protein product, practical utility, and limitations of each marker are discussed in detail.

DATA SOURCES

Literature review, authors' research data, and personal practice experience serve as sources.

CONCLUSIONS

There are many diagnostically useful immunohistochemical markers to help confirm the diagnosis of many different soft tissue tumor types, some of which have reduced the need for additional, and more costly, studies, such as fluorescence in situ hybridization. However, no one marker is 100% specific for a given tumor, and knowledge of potential pitfalls and overlap in patterns of staining among other tumor types is crucial to ensure the appropriate application of these markers in clinical practice.

Diagnostic Immunohistochemistry in Cutaneous Neoplasia: An Update

Immunohistochemistry (IHC) is an important adjunct in the diagnosis of neoplastic skin diseases. In addition to the many established IHC markers currently in use, new markers continue to emerge, although their general acceptance and routine application requires robust validation. Here, we summarize the most well-established and commonly used biomarkers along with an array of newer ones reported in the past several decades that either demonstrate or hold high clinical promise in the field of cutaneous pathology. We also highlight recent applications of novel IHC markers in melanoma diagnosis including genetic mutation status markers [e.g. BRAF (v-raf murine sarcoma viral oncogene homolog B) and NRAS (neuroblastoma RAS viral oncogene homolog)] and an epigenetic alteration marker (e.g. 5-hydroxymethylcytosine). We specifically focus on the role of IHC in the differential diagnosis of cutaneous lesions that fall under the following categories: melanoma, epidermal tumors with an intraepidermal epitheliomatous pattern, spindle cell lesions of the dermis, small round blue cell tumors of the dermis, and cutaneous adnexal tumors. While IHC is a valuable tool in diagnostic dermatopathology, marker selection and interpretation must be highly informed by clinical context and the histologic differential diagnosis. With rapid progress in our understanding of the genetic and epigenetic mechanisms of tumorigenesis, new IHC markers will continue to emerge in the field of diagnostic dermatopathology.

Needle biopsy of mesenchymal lesions of the head and neck: Evolving concepts and new strategies for diagnosis

Sarcomas are a rare and heterogeneous group of neoplasms that can be a significant diagnostic challenge in routine practice. Recent advances in the understanding of molecular mechanisms underlying oncogenesis have led to an array of novel diagnostic tools. Here we review several sarcomas of the head and neck region, focusing on neoplasms with new molecular findings and highlighting novel diagnostic tools.

The spectrum of rare morphological variants of cutaneous epithelioid angiosarcoma

AIMS

Unusual cytoplasmic alterations have recently been reported in poorly differentiated cutaneous angiosarcoma, making an accurate diagnosis challenging. As these tumours remain poorly documented, we aimed to study their clinicopathological characteristics more comprehensively.

METHODS AND RESULTS

Six cutaneous angiosarcomas with unusual cytoplasmic alterations were identified from referral files. All tumours arose as nodules or plaques (range: 05-195 mm) on sun-damaged skin of the head and neck of elderly males (median age: 76.5 years). Histologically, the tumours were composed of enlarged epithelioid cells showing prominent signet ring (n = 3), foam (n = 2) or granular cell (n = 1) change. Vasoformative elements were only focally noted. By immunohistochemistry, all tumours expressed CD31 and avian v-ets erythroblastosis virus E26 oncogene homologue (ERG). Foam cell change was associated with additional expression of CD68 and CD163. Follow-up (median: 8 months) showed death from disease (n = 1), death from a gastrointestinal bleed (n = 1), and a cutaneous metastasis (n = 1). Only two patients are alive with no evidence of disease.

CONCLUSIONS

Our findings outline the morphological spectrum of cytoplasmic change in cutaneous angiosarcoma. Awareness and a high degree of suspicion in the context of tumours affecting sun-damaged skin of the elderly are necessary to direct appropriate immunohistochemical work-up with inclusion of the endothelial cell markers CD31 and ERG.

[Cutaneous angiosarcoma: new aspects]

Cutaneous angiosarcoma is an aggressive endothelial cell neoplasm with a high associated mortality. Reliable and confident diagnosis is necessary but frequently challenging due to the wide morphological spectrum and broad differential diagnosis of the disease. Furthermore, the final diagnosis often relies on immunohistochemical evidence of endothelial cell differentiation which is further complicated by the lack of sensitivity and specificity of conventional endothelial cell markers. The following article outlines the clinical and histological spectrum of cutaneous angiosarcoma with emphasis on novel findings relating to immunohistochemistry and molecular genetics in the context of the relevant differential diagnosis.

The utility of ERG, CD31 and CD34 in the cytological diagnosis of angiosarcoma: an analysis of 25 cases

AIMS

Erythroblast transformation specific related gene (ERG), a proto-oncogene member of the erythroblast transformation specific transcription factor family, is a sensitive marker of endothelial differentiation and is expressed in vascular tumours, including angiosarcomas (AS). Immunohistochemistry is necessary for the diagnosis of AS in fine needle aspirates where low cellularity and lack of preserved tissue architecture impedes diagnosis. The aim of this study was to assess the utility of an ERG-enriched immunohistochemistry panel in the cytological diagnosis of AS.

METHODS

25 AS diagnosed on fine needle aspirates were stained for ERG, CD31, CD34, and AE1/AE3. Staining intensity and percentage tumour cell positivity were evaluated. Spearman's correlation was assessed for significant correlations between antibodies.

RESULTS

Sensitivities for ERG, CD31, CD34 and AE1/AE3 were 100%, 100%, 60% and 21%, respectively. Spearman's analysis revealed that ERG and CD31 staining correlated significantly; there was no significant correlation between CD31 and CD34 staining.

CONCLUSIONS

With equal sensitivity to, and strong correlation with CD31, ERG staining is highly suitable for the cytological diagnosis of AS. ERG and CD31 are more sensitive vascular markers than CD34. ERG, a nuclear stain, complements the cytoplasmic/membranous staining of CD31. Used in conjunction with CD31, ERG can corroborate the diagnosis of AS.

Transcription factor ERG is a specific and sensitive diagnostic marker for hepatic angiosarcoma

AIM: To investigate the expression of ERG, CD34, CD31 (PECAM-1, platelet/endothelial cell adhesion molecule 1) and factor VIII-related antigen (FVIIIRAg) in the diagnosis of hepatic angiosarcoma patients.

METHODS: Patient samples were collected from January 1986 to December 2012 from the People’s Liberation Army General Hospital in Beijing, China. We obtained twenty-four samples of hepatic angiosarcoma (HAS) that were confirmed by two pathologist. The samples were the result of three autopsy cases, eight biopsy cases and 13 patients who underwent surgical tumor removal. The HAS cases accounted for 2.23% (24/1075) of all hepatic vascular tumors at the hospital during the same time period. Patient histories including age, gender, clinical manifestations, medical treatments, laboratory tests, radiological images, histological observations and outcomes for each case were analyzed in detail. All samples were evaluated histologically with hematoxylin and eosin staining. Using immunohistochemistry, the expression and localization of ERG was examined in all HAS specimens and compared to the known endothelial markers CD34, CD31 and FVIIIRAg. The endothelial markers were also evaluated in a panel of non-HAS tumors.

RESULTS: This cohort of 24 HAS cases is, to the best of our knowledge, currently the largest cohort in the world in the publicly available literature. Hepatic angiosarcoma tissue samples were obtained from 14 males and 10 females with a mean age of 50.6 years (range: 7-86 years). The patients presented with the following clinical manifestations: abdominal pain (16/24), back pain (3/24), heart palpitations (1/20), cough (1/24) or no clinical symptoms (3/24). Tumors were predominantly localized in the right hepatic lobe (15/24) or left hepatic lobe (6/24), or a diffuse growth on the right and left hepatic lobes (3/24). Eleven patients underwent surgical resection (45.8%), two patients received a liver transplant (8.3%), eight patients received interventional therapy (33.3%) and three patients received no treatment (lesions discovered at autopsy, 12.5%). Postoperative follow-up of patients revealed that 87.5% (21/24) of patients had died and three cases were not able to be tracked. In all cases, the mean survival time was 12.1 mo. While 100% of the HAS samples were positive for ERG expression, expression of the other markers was more variable. CD31 was expressed in 79.2% (19/24) of samples, CD34 was expressed in 87.5% (21/24) of samples and FVIIIRAg was expressed in 41.7% (10/24) of samples.

CONCLUSION: ERG is a more sensitive and specific diagnostic marker for hepatic angiosarcoma in comparison to CD31, CD34 and FVIIIRAg.

ERG and FLI1 protein expression in epithelioid sarcoma

Epithelioid sarcoma is a rare, aggressive keratin-positive sarcoma that co-expresses CD34 in 50% of cases and may mimic an angiosarcoma. Recently, we have observed one case of epithelioid sarcoma that labeled for ERG, an ETS family regulatory transcription factor, which is considered to be a reliable marker for vascular differentiation. We investigated the prevalence of nuclear expression of ERG and FLI1, a homologous transcription factor, in these tumors. A formalin-fixed paraffin-embedded tissue microarray of 37 epithelioid sarcomas was examined. Immunohistochemistry was performed using anti-ERG monoclonal antibody to the N-terminus, anti-ERG monoclonal antibody to the C-terminus and anti-FLI1 monoclonal antibody. Comparison was made with CD34, CD31, and D2-40 labeling. The extent of immunoreactivity was graded according to the percentage of positive tumor cell nuclei (0: no staining; 1+: <5%; 2+: 5-25%; 3+: 26-50%; 4+: 51-75%; and 5+: 76-100%), and the intensity of staining was graded as weak, moderate, or strong. Nuclear staining for the N-terminus of ERG was seen in 19 out of 28 cases: 10 with diffuse(4 to 5+) strong/moderate labeling; 1 with 2+ moderate labeling and 8 with weak labeling (1 to 4+, 2 each). Focal staining for the C-terminus of ERG was seen in only 1 out of 29 cases (2+ moderate). FLI1 labeling was seen in nearly all (28 out of 30) cases: 16 with diffuse (5+) predominantly moderate labeling, and 8 cases with diffuse(5+) weak labeling. The remainder had variable moderate (1 to 3+) or weak (1 to 4+) FLI1 staining. CD34 was positive in 22 out of 30 cases and D2-40 was found to be positive in 22 out of 31 cases. All cases were negative for CD31 (0 out of 30). Epithelioid sarcoma can label with antibodies to the N-terminus of ERG, FLI1, and D2-40, which may cause diagnostic confusion for a vascular tumor. A panel of other antibodies including SMARCB1 and CD31 should be used in evaluating these tumors. ERG antibody selection is also critical, as those directed against the C-terminus are less likely to label epithelioid sarcoma.

Superficial CD34-positive fibroblastic tumor: report of 18 cases of a distinctive low-grade mesenchymal neoplasm of intermediate (borderline) malignancy

Fibroblastic mesenchymal tumors show a spectrum of biological behavior, from benign to fully malignant. We report our experience of two decades with a distinctive, previously undescribed low-grade fibroblastic tumor of the superficial soft tissues. Eighteen cases were identified within our consultation files, previously coded as 'low-grade sarcoma, not further classified' and 'malignant fibrous histiocytoma, low grade'. The tumors occurred in adults (median age 38 years, range 20-76 years) of either sex (10 males and 8 females), ranged in size from 1.5 to 10 cm (mean 4.1 cm), and were confined to the superficial soft tissues of the thigh (N=5), knee (N=2), and other sites. Histological features included a fascicular growth pattern of the neoplastic spindled cells with striking, often bizarre cellular pleomorphism and variably prominent nucleoli. Necrosis was seen in one case. All cases showed strong, diffuse CD34 positivity and 68% of tested cases demonstrated focal cytokeratin expression. Desmin, ERG, FLI-1, smooth muscle actin, and S100 protein were negative. TP53 overexpression was absent. Fluorescence in-situ hybridization studies for TGFBR3 and/or MGEA5 rearrangements were negative in all tested cases. Clinical follow-up was available in 13 patients (median duration of 24 months; range 1-104 months). Twelve of 13 patients had no disease recurrence. One patient had regional lymph node metastases, 7 years after incomplete excision of the primary tumor. All patients are currently alive and disease free. The unique clinicopathological features of superficial CD34-positive fibroblastic tumor define them as a novel subset of low-grade fibroblastic neoplasms, best considered to be of borderline malignancy.

Novel uses of immunohistochemistry in the diagnosis and classification of soft tissue tumors

Immunohistochemistry plays a key role in the diagnosis of soft tissue tumors. Until recently, however, the primary purpose of immunohistochemistry in this context was simply to attempt to demonstrate a line of differentiation. Unfortunately, most traditional markers (predominantly directed against cytoplasmic determinants) show relatively limited specificity. Over the last decade or so, much more specific immunohistochemical markers for soft tissue tumors have been developed. This review will provide an update of some of the most useful new diagnostic markers, which are significantly changing clinical practice for surgical pathologists, separated into three general categories: (1) lineage-restricted transcription factors, (2) protein correlates of molecular alterations, and (3) diagnostic markers identified by gene expression profiling.

Immunohistochemistry of soft tissue tumours - review with emphasis on 10 markers

Immunohistochemistry is an integral component in the proper analysis of soft tissue tumours, and a simple panel of six markers is useful in practical triage: CD34, desmin, epithelial membrane antigen (EMA), keratin cocktail AE1/AE3, S100 protein and alpha smooth muscle actin (SMA). These markers frequently assist in the differential diagnosis of fibroblastic, myoid, nerve sheath and perineurial cell tumours, synovial and epithelioid sarcoma and others. However, they all are multispecific, so that one has to be cognizant of their distribution in normal and neoplastic tissues. Four additional useful markers for specific tumour types are discussed here: CD31 and ERG for vascular endothelial tumours, and KIT and DOG1/Ano-1 for gastrointestinal stromal tumours (GISTs). However, hardly any marker is totally monospecific for any one type of tumour. Furthermore, variably lineage-specific markers do not usually distinguish between benign and malignant proliferations, so that this distinction has to be made on histological grounds. Immunohistochemical evaluation is most useful, efficient and cost-effective when used in the context of careful histological evaluation by an experienced pathologist, aware of all diagnostic entities and their histological spectra. Additional diagnostic steps that must be considered in difficult cases include clinicoradiological correlation and additional sampling of remaining wet tissue, if possible.

Newly Available Antibodies With Practical Applications in Surgical Pathology

Selected antibodies that have become available in recent years and have applications in diagnostic pathology are discussed. They include antibodies that are organ-related, provide information on cellular differentiation or histogenetic type, have predictive value in tumors, and highlight infective agents. PAX8 (paired box gene 8) is a marker expressed in the lower female genital tract, thyroid, and kidney and their tumors. Napsin A is expressed in the lung and kidney and is an alternative marker for pulmonary adenocarcinoma. Arginase A is a sensitive and specific marker for liver tumors. ERG (Ets-related gene) is an excellent marker for endothelium and vascular tumors as well as prostatic cancer (about 50% of cases). SOX10 (SRY-related HMG box) is expressed predominantly in melanocytic and Schwann cells and the corresponding tumors. DOG1 (discovered on GIST 1) is an excellent marker for gastrointestinal stromal tumor (GIST) and acinic cell carcinoma. OCT3/4 is a pan–germ cell tumor marker, except yolk sac tumor. SALL4 is positive in various types of germ cell tumors, including yolk sac tumor. MUC4 (mucin-related antigen 4) is a sensitive and specific marker for low-grade fibromyxoid sarcoma. Langerin is a specific marker for Langerhans cells and their tumors. SOX11 is a sensitive marker for mantle cell lymphoma. New generation antibodies against anaplastic lymphoma kinase (ALK) are required to reliably demonstrate ALK gene translocation in pulmonary carcinomas. Lack of expression of succinate dehydrogenase B is seen in paragangliomas of the hereditary form and in the pediatric type of GIST. Antibodies against Trepenoma pallidum can facilitate the diagnosis of syphilis, whereas those against SV40 (simian virus 40) are helpful for diagnosis of BK virus infection and progressive multifocal leukoencephalopathy.

Association of D2-40 and MMP-1 expression with cyst formation in lung metastatic lesions of cutaneous angiosarcoma on the scalp: immunohistochemical analysis of 23 autopsy cases

Cutaneous angiosarcoma of the scalp can rapidly develop into pulmonary metastasis. The pulmonary metastatic lesions display a unique appearance, so-called thin-walled cysts, which cause a fatal relapsed pneumothorax by rupturing. We analyzed 23 autopsy cases of angiosarcoma with pulmonary metastasis to elucidate the mechanism of the thin-walled cyst development. Of the 23 cases of cutaneous angiosarcoma of the scalp with pulmonary metastasis, radiological examination revealed pulmonary metastatic lesions as thin-walled cysts (39%), nodules (39%), mixed cysts and nodules (13%), and ground-glass opacity (9%). All the cases but one with cystic metastases were complicated by pneumothorax. The cystic lesions were accompanied by podoplanin (D2-40)-positive tumor cells in the luminal surface of the cysts. In both primary cutaneous lesions and pulmonary metastatic lesions, the D2-40 expression was positive for angiosarcoma cells in 100% and 92% of the cases, respectively. While the estrogen-regulated gene (ERG) expression was also positive for most of the primary and metastatic pulmonary angiosarcomas, D2-40 was a more useful marker to differentiate tumor cells from the background than was the ERG expression of the vascular endothelium. Matrix metalloproteinase-1 (MMP-1) expression was also predominant in primary lesions (95%) and pulmonary metastatic lesions (82.6%). Proteinases, like MMP-1, might be associated with a developing thin-walled cyst, although there were no differences in the MMP-1 expression in either the cystic or nodular metastasis. Two extremely aggressive cases showed cystic metastasis with central necrosis that was not observed in other cases. These results suggest a pathogenesis of thin-walled cysts in some progressive cases.

Atypical fibroxanthoma with pseudoangiomatous features: a histological and immunohistochemical mimic of cutaneous angiosarcoma

Atypical fibroxanthoma and pleomorphic dermal sarcoma may be difficult to separate from cutaneous angiosarcoma. We aim to study the morphological spectrum of pseudoangiomatous features in these tumors and the value of staining for endothelial markers CD31, CD34, FLI1, and ERG. Eleven atypical fibroxanthomas and 3 pleomorphic dermal sarcomas were identified. All tumors arose on sun-damaged skin of elderly men. Atypical fibroxanthomas were nodular and confined to the dermis, whereas pleomorphic dermal sarcoma invaded into underlying fascia. All tumors were composed of pleomorphic epithelioid and spindle cells showing blood-filled spaces and intratumoral hemorrhage. Intracytoplasmic vacuoles (n = 4), hemosiderin deposition (n = 2), and keloidal stromal change (n = 1) were also noted. Immunohistochemically, CD31 was expressed in 43% of cases, FLI1 in 79% and smooth muscle actin in 50%. Staining for CD34, ERG, S100, HMB-45, desmin, p63 and cytokeratins was negative. Follow up (median, 43.1 months; range 1-100), available for 10 patients, showed no adverse outcome. Pseudoangiomatous features and aberrant expression of CD31 and FLI1 in atypical fibroxanthoma and pleomorphic dermal sarcoma may lead to an erroneous diagnosis of cutaneous angiosarcoma. Negativity for CD34 and ERG, in particular, is a reliable differentiating feature in this setting.

Angiosarcomas and other sarcomas of endothelial origin

Although benign hemangiomas are among the most common diagnoses among connective tissue tumors, angiosarcomas and other sarcomas arising from blood vessels are rare, even among sarcomas. Because endothelial tumors have unique embryonal derivation compared with other sarcomas, it is not surprising they have unique characteristics. Herein are reviewed some of these unique characteristics and therapeutic options for patients with some of these diagnoses, highlighting the potential of new agents for these tumors, which will in all likelihood also impact treatment on more common cancers.