Epithelioid sarcoma mimicking angiosarcoma: the value of immunohistochemistry in the differential diagnosis

Primary Epithelioid Angiosarcoma of the Adrenal Gland Case Report and Review of the Literature

Primary angiosarcoma of the adrenal gland is extremely rare. Here, we report on a 70-year-old man with an angiosarcoma of the right adrenal gland who died 3 weeks after tumor resection due to intestinal infarction and acute renal failure. No metastases were found at autopsy. Histologically, the tumor showed a predominantly epithelioid differentiation. Immunohistochemical examination revealed positive reactivity for cytokeratin, epithelial membrane antigen, vimentin, factor Vlll-related antigen, CD31, CD34 and Ulex eu-ropaeus agglutinin-l. Features of endothelial origin were also demonstrable by electron microscopy. The differential diagnosis of this uncommon neoplasm is discussed. The present case emphasizes problems in differential diagnosis that arise from its epithelioid differentiation. A review of the literature underlines the poor clinical outcome of adrenal angiosarcoma.

Right femoral pathological fracture caused by primary bone epithelioid angiosarcoma: Case report

RATIONALE

Epithelioid angiosarcoma (EAS) is an extremely rare malignant disease, which accounts no more than 1% of all soft tissue sarcomas. In this article, we would report a new case of EAS with multiple bone destruction and right femoral pathological fracture, which was an even rarer manifestation of EAS.

PATIENT CONCERNS

In this case, a 64-year-old man with right femoral fracture was reported. He had suffered from a progressive low back pain for about 8 months, and the imaging examinations prompted a multiple bone destruction in his vertebra and lower limbs. He then got a right femoral fracture without any obvious traumatic injury, and came to our hospital.

INTERVENTIONS

He underwent an operation of radical resection, bone cement filling and dynamic condylar screw internal fixation. During the operation, we found that the soft tissue around the fracture had a rotten fish change, which suggested a malignant disease.

DIAGNOSES

The postoperative pathological diagnosis reported an EAS, which is extremely rare and highly malignant.

OUTCOMES

The patient died in 83 days after the surgery, and the survival time from the symptoms started to the end was only 11 months, which showed a rapid progress and poor prognosis of EAS.

LESSONS

EAS is very hard to be diagnosed by clinical manifestation or radiological examinations. As in our case, pathological analysis is the final diagnosis. The images of the patient may offer some tips for the skeletal presentation of EAS, and do more help in future study of this disease.

Epithelioid Sarcoma: Diagnostic Features and Genetics

Epithelioid sarcoma (ES) is a rare, aggressive soft-tissue neoplasm of uncertain differentiation, characterized by nodular aggregates of epithelioid cells, which are immunoreactive to cytokeratins (CKs) and epithelial membrane antigen, and often for CD34. It has a propensity for multifocal disease at presentation, local recurrence, and regional metastasis. These are aggressive neoplasms with particularly poor prognosis after regional or distant metastatic disease, for which surgical resection is still the mainstay of treatment, and options for patients with metastatic disease remain undefined. There are 2 distinct variants: classic ES, which typically presents as a subcutaneous or deep dermal mass in the distal extremities of young adults and comprises nodular distributions of relatively uniform epithelioid cells with central necrosis, and the proximal variant, which has a predilection for proximal limbs and limb girdles and the midline of the trunk, which is composed of sheets of larger, more atypical cells with variable rhabdoid morphology. Both classic and proximal-type ESs are associated with the loss of SMARCB1/INI1 protein expression, but appear otherwise molecularly relatively heterogeneous. We review classic and proximal-type ES, discussing morphology, immunohistochemical and genetic findings, the differential diagnosis, and the future potential for targeted therapies.

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.

A novel angiomatoid epithelioid sarcoma cell line, Asra-EPS, forming tumors with large cysts containing hemorrhagic fluid in vivo

BACKGROUND

Whereas we can use several human epithelioid sarcoma (ES) cell lines for basic and preclinical research, an angiomatoid ES cell line has not been reported to date. We have treated a case of an angiomatoid ES developing in the right upper extremity of a 67-year-old man.

METHODS

An angiomatoid ES cell line, Asra-EPS was newly established and characterized for its morphology, growth rate and chromosomal analysis. Tumorigenicity of Asra-EPS cells was also analyzed in athymic nude mice.

RESULTS

Asra-EPS cells were round, polygonal or spindle-shaped with an abundant cytoplasm and have been maintained continuously in vitro for over 150 passages during more than 15 months. These cells secreted cancer antigen 125 (CA 125), interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) into the culture medium. Asra-EPS cells were tumorigenic when implanted in nude mice with tumors reaching a volume of 1000 mm3 at around 50 days. Histological features of tumors formed in mice were essentially the same as those of the original tumor, exhibiting a multinodular proliferation of eosinophilic epithelioid and spindle-shaped cells with prominent areas of hemorrhage and blood-filled cystic spaces strikingly corresponding to the potential of hemorrhagic cyst formation in the original tumor. They showed immunopositive staining for cytokeratins (AE1/AE3 and CAM5.2), epithelial membrane antigen (EMA), vimentin, CD31, CD34 and CA 125, but negative for integrase interactor 1 (INI-1) and factor VIII-related antigen.

CONCLUSIONS

The established cell line represents a biologically relevant new tool to investigate the molecular pathology of human angiomatoid ES and to evaluate the efficacy of novel therapeutics both in vitro and in vivo.

Soft tissue tumors of uncertain origin

Many soft tissue tumors of childhood lack obvious differentiation toward a defined mesenchymal tissue type or have a phenotype that does not correspond to any defined normal tissue. These challenging tumors are currently regarded as neoplasms of uncertain differentiation. Nonetheless, there have been great strides in the understanding of their pathologic and genetic features and biologic underpinnings. The application of new genetic information to the pathologic diagnosis among this group of tumors is an emerging area in diagnostic pediatric pathology. This article reviews the clinicopathologic features of tumors of uncertain and/or miscellaneous origin, with an emphasis on the unique aspects of these neoplasms in children and adolescents, use of diagnostic adjuncts, and differential diagnosis.

Epithelioid sarcoma

Epithelioid sarcomas are rare, mesenchymal tumors of unknown histogenesis and display multidirectional differentiation, which is predominantly epithelial. They have no normal cellular counterpart and differ from both synovial sarcoma and carcinoma. They account for less than 1% of all soft tissue sarcomas and are usually slow growing, with peak incidence in young adult men and occur predominantly in extremities. Histologically, they form nodules, with central necrosis surrounded by bland, polygonal cells with eosinophilic cytoplasm and peripheral spindling. They regularly express vimentin, cytokeratins, epithelial membrane antigen, and CD34, whereas staining is usually negative with S100, desmin, and FLI-1. Ultrastructurally, they display epithelial and mesenchymal features, including myofibroblastic differentiation. They manifest no specific cytogenetic findings, but several cases have displayed chromosomal abnormalities in 22q region. Clinically, they have a high recurrence rate, and up to 50% of epithelioid sarcomas metastasize. Proximal, fibroma-like, and angiomatoid variants have been described. The proximal variant (with larger cells, prominent nucleoli, and rhabdoid changes) is clinically more aggressive.

Angiosarcomas arising in the viscera and soft tissue of children and young adults: a clinicopathologic study of 15 cases

Angiosarcomas are rare tumors that predominantly affect adult and elderly patients and pursue an aggressive clinical course with high mortality. Although angiosarcomas are well described in a variety of clinical settings, they have been incompletely characterized. We identified 15 high-grade angiosarcomas arising from the viscera and soft tissue of patients 21 years old and younger from institutional and consultation files. Both clinical (patient age, tumor site, tumor size, tumor focality) and histologic features including growth pattern (vasoformative vs. solid), nuclear grade (high vs. low), mitotic rate (mitotic figures/10 high-power fields), necrosis (present vs. absent), and cell shape (epithelioid vs. nonepithelioid) were assessed. Tumors arose in both sexes (8 males; 7 females); age at diagnosis ranged from 3 months to 19 years (mean, 10 y, 5 mo; median, 11 y). Tumors were located in the mediastinum (7), visceral organs (2 in liver, 1 in spleen), breast (2), mesentery (1), pelvis (1), and deep soft tissue of upper extremity (1). Tumor size was documented for 8 patients (range 3.5 to 13 cm; mean 8.1 cm). Eight cases showed epithelioid morphology and 7 cases were primarily spindled. Of 8 cases assessed for podoplanin expression by immunohistochemistry, 7 were negative and 1 was positive. Clinical follow-up was obtained for all patients: 10 (67%) died of disease (range, 27 mo to 11 y; mean, 6 y 8 mo) and 4 patients were alive without disease (range, 27 to 132 mo; mean, 79 mo). Although extremely rare, angiosarcomas do affect children and young adults and this diagnosis should be considered in atypical vascular tumors occurring in the mediastinum and those with brisk mitotic activity and/or necrosis.

Myxoid Epithelioid Sarcoma: Clinicopathologic Analysis of 2 Cases

In the nearly 4 decades since its original delineation as a distinct clinicopathologic entity, several morphologic variations of epithelioid sarcoma have been described. Proximal, angiomatoid, and fibroma-like variants have been reported, as have cases displaying significant hyalinization, calcification, and/or ossification. Furthermore, it has long been recognized that epithelioid sarcoma may display focal myxoid change. Herein, the authors describe 2 examples of epithelioid sarcoma that displayed diffuse myxoid change. Both cases were otherwise typical, both morphologically and immunophenotypically, of epithelioid sarcoma. The tumors in both cases were localized, and the patients were treated with wide local excision followed by adjuvant radiotherapy. The patients are free of disease recurrence after 25 and 37 months of follow-up. Differential considerations that may arise because of the composite of morphologic and immunophenotypic findings noted in these cases are discussed, especially if encountered in a small biopsy. These cases further expand the morphologic spectrum of epithelioid sarcoma.

Human chorionic gonadotrophin producing epithelioid sarcoma metastatic to the placenta

Pregnancy complicated by sarcoma is a rare event, and metastasis to the placenta is exceptionally rare. Of reported malignancies involving the products of conception, only 8% are sarcomas. We report the first case of placental metastasis of an epithelioid sarcoma, an uncommon malignancy which most frequently affects young adults. In addition to the typical histological features and immunophenotypic profile expected of epithelioid sarcoma, this tumor also expressed human chorionic gonadotrophin (HCG). Although uncharacteristic, the production of HCG has been previously reported in other nontrophoblastic tumors. It may have contributed to the pathogenesis of the tumor metastatic to the placenta in this case.

Proximal-type epithelioid sarcoma--a rare, aggressive subtype of epithelioid sarcoma presenting as a recurrent perineal mass in a middle-aged male

BACKGROUND

Epithelioid sarcoma (ES) is an uncommon soft tissue sarcoma. Lately, subtypes of ES, including proximal-type ES have been recognized, with relatively few reports on such cases.

CASE PRESENTATION

A 47-year-old male presented with a perineal soft tissue mass that was excised elsewhere and the biopsy was submitted for a review diagnosis. On histology, a multi nodular tumor was seen comprising sheets of oval to polygonal cells with moderate amount of cytoplasm. Interspersed were larger, rhabdoid cells with abundant eosinophilic cytoplasm and prominent nucleoli. Focal necrosis was noted. A wide panel of immunohistochemical (IHC) markers was performed to rule out a range of differential diagnoses, including a poorly differentiated carcinoma, a melanoma and a variety of sarcomas with epithelioid differentiation. On IHC, the tumor cells showed a polyphenotypic expression, including positivity for epithelial markers i.e cytokeratin (CK), CK7, EMA and mesenchymal markers like vimentin and CD 34. Desmin was focally positive. CK20, CEA, S-100, HMB-45, SMA, LCA and CD31 were negative. A diagnosis of a proximal-type ES was formed. Six moths later, despite adjuvant chemo and radiotherapy (CT and RT), the patient continued to have the lesion and was referred again. In addition to the earlier histological features, sections from the persistent tumor mass showed an increased number of larger cells along with multinucleated tumor giant cells.

CONCLUSION

The value of identifying this uncommon tumor from a list of differential diagnoses is in view of its aggressive behavior, as seen in our case. A wide excision with clear margins is imperative with options of post-operative CT/RT in individual cases during a close follow-up.

Proximal-type epithelioid sarcoma with elevated serum CA 125: report of a case with CA 125 immunoreactivity

Proximal-type epithelioid sarcoma is a recently described rare soft tissue neoplasm. It is commonly found in the pelvic, perineal, and genital areas in middle-aged or older adults, as compared with the classic type of epithelioid sarcoma, which arises in the distal portion of the extremities in adolescents and young adults. Proximal-type epithelioid sarcoma has a more aggressive clinical behavior than the classic type of epithelioid sarcoma. Proximal-type epithelioid sarcoma is histologically characterized by a diffuse proliferation of epithelioid cells with prominent rhabdoid feature. Recently, a few cases have been reported of epithelioid sarcoma with elevated serum CA 125 level and CA 125 immunoreactivity in neoplastic cells. These cases raise the possibility that serum CA 125 and CA 125 immunoreactivity could be a useful tumor marker for diagnosing and monitoring epithelioid sarcoma. We describe a case of proximal-type epithelioid sarcoma with elevated serum CA 125 level (up to 3395 U/mL [reference range, <35 U/mL]) in a 12-year-old girl who presented with a huge pelvic mass measuring 12 cm in greatest dimension. The serum CA 125 level dropped to 452 U/mL after a debulking operation of the mass. Immunostaining for CA 125 demonstrated a positive immunoreactivity in the neoplastic cells. She received one cycle of chemotherapy and died of the disease 2 months after diagnosis. This case represented a rare example of proximal-type epithelioid sarcoma with elevated serum CA 125 and immunoreactivity for CA 125 in the tumor cells. Based on the previous reported cases and the current case, serum CA 125 as well as immunohistochemical stain for CA 125 may be a useful tumor marker of proximal-type epithelioid sarcoma.

Epithelioid sarcoma of Enzinger

Epithelioid sarcoma was named in 1970 in a classic paper by Enzinger, who expanded the observations in a larger series in 1985. He defined a sarcoma with a peak incidence in young adult males and a predilection for extremities, involving subcutis or deeper tissue and extending along tendon sheaths or aponeuroses. The tumor forms nodules with central necrosis surrounded by bland polygonal cells with eosinophilic cytoplasm and peripheral spindling. Fibromalike, angiomatoid, and proximal aggressive variants (with larger cells, prominent nuceloi, and rhabdoid change) have since been described. Epithelioid sarcomas regularly express vimentin, cytokeratins, and epithelial membrane antigen, and about half are positive for CD34, but a wide range of other antigens can be expressed. S100 protein, desmin, and FLI-1 are usually negative. The ultrastructure displays epithelial and mesenchymal features including myofibroblastic differentiation. There are no specific genetic findings but several cases display chromosomal abnormalities in the 22q region. The tumor has no normal cellular counterpart and differs from both synovial sarcoma and carcinoma. There is a wide differential diagnosis from numerous benign and malignant conditions, including granuloma annulare, melanoma, and epithelioid vascular neoplasms. Epithelioid sarcoma has a high recurrence rate, which can be reduced by adequate surgery, and up to 40% metastasize, to regional lymph nodes, to lung, and other locations including scalp. Adverse prognostic factors include large size, male sex, older age, necrosis, vascular invasion, rhabdoid cytomorphology, and inadequate excision. Thirty-six years after Enzinger's original account, epithelioid sarcoma remains a clinically and pathologically distinct, indolent but aggressive sarcoma of indeterminate lineage.

Angiosarcoma involving the gastrointestinal tract: a series of primary and metastatic cases

Angiosarcoma occurs very rarely in the intestinal tract as either a primary or metastatic malignancy and can present great diagnostic difficulty, especially when it displays epithelioid cytomorphology. Since only isolated case reports have been published, the purpose of this study is to more fully delineate the histopathological and clinical features from a series of 8 angiosarcomas involving the gastrointestinal tract. There were 5 male and 3 female patients whose ages ranged from 25-85 years (median 57). Presenting symptoms included intestinal bleeding, anemia and pain. Five cases involved the small bowel and 3 involved the colon/rectum. Four cases were primary to the intestinal tract, 2 patients initially presented with secondary involvement of the large bowel from occult retroperitoneal primaries, 1 patient presented with disseminated disease including small bowel involvement, and 1 case was metastatic from a breast primary. Seven cases were composed predominantly of sheets of malignant appearing epithelioid cells with subtle areas forming cleft-like spaces suggestive of vascular differentiation. Immunohistochemical studies revealed the lesional cells to be immunoreactive for CD31 (8/8), CD34 (8/8), Factor VIII (8/8), cytokeratins AE1/AE3 (7/8), cytokeratin 7 (2/8), Cam5.2/cytokeratin 8 (5/8), and cytokeratin 19 (5/8). Cytokeratin 20 was negative in all eight cases, which contrasts sharply with the characteristic positivity for cytokeratin 20 in virtually all intestinal carcinomas. One case was weakly and focally positive for EMA and all cases were negative for S-100 protein. Cytokeratin staining was variable and ranged from focal to extensive. Follow-up was available in eight cases and ranged from 1-33 months (median 12.5). Five patients died of disease, between 1 and 33 months (median 6) after diagnosis. One recently diagnosed patient is alive with disease 18 months after diagnosis, and one patient is free of disease 27 months after original diagnosis. Angiosarcomas of the gastrointestinal tract commonly display epithelioid cytomorphology, may be diffusely and strongly positive for cytokeratins and only show subtle signs of vascular differentiation, creating potential diagnostic confusion with primary or metastatic carcinoma. Given the clinically aggressive behavior of angiosarcoma, proper classification and treatment is important. Immunohistochemistry with vascular markers, CK20, and S-100 protein may be helpful in differentiating angiosarcoma from carcinoma and melanoma.

Epithelioid sarcoma metastatic to the tongue: a rare entity

Epithelioid sarcoma (ES) typically arises as a firm nodule on the extremities of young men. The tumor is remarkable for diagnostic difficulties both clinically and histopathologically resulting in a high frequency of initial misdiagnosis. ES is also known to have a high rate of recurrence and high rate of metastasis predominantly to the lymph nodes, lungs, and scalp. Herein, the second case of ES with metastasis to the tongue is reported.

Epithelioid sarcoma: new insights based on an extended immunohistochemical analysis

CONTEXT

Epithelioid sarcoma has a distinctive epithelioid phenotype and characteristically exhibits immunohistochemical reactivity for epithelial markers (keratins and epithelial membrane antigen) and mesenchymal markers (most notably vimentin and CD34). Antibodies to certain keratin subunits and other novel antigens now available to surgical pathologists have not been tested on a large number of cases.

OBJECTIVE

To assist in the differential diagnosis of epithelioid sarcoma and to help elucidate its histogenesis through an expanded immunohistochemical profile.

DESIGN

Immunohistochemical testing with diverse antibodies was performed on 95 archived epithelioid sarcomas including 73 classic and 22 histologically variant subtypes retrieved from the files of the Armed Forces Institute of Pathology.

RESULTS

Immunohistochemical reactivity (number positive/number of cases tested [percent positive], frequency of staining) included keratin 14 (31/64 [48%], variable), gamma-catenin (35/74 [47%], variable), keratin 5/6 (10/33 [30%], focal), calretinin (8/40 [20%], focal), keratin 20 (11/71 [15%], focal), p63 (3/20 [15%], focal), whereas 9 invasive cutaneous squamous cell carcinomas showed strong p63 positivity, epithelial-specific antigen (10/74 [14%], variable), CD117/Kit (5/37 [14%], focal), keratin 15 (3/23 [13%], rare cell), mesothelin (2/64 [3%], rare cell), and CD10 (1/41 [2%], rare cell). No reactivity was observed for keratins 2, 5, and 10.

CONCLUSIONS

Diagnostically, p63 and keratin 5/6 distinguish cutaneous squamous cell carcinoma (positive) from epithelioid sarcoma (usually negative). No single immunomarker was able to distinguish the main 4 histologic subtypes of epithelioid sarcoma, indicating that they are all histogenetically related lesions. The limited expression of specific keratin subtypes used in our study supports the notion that epithelioid sarcoma is a mesenchymal neoplasm capable of partial epithelial transformation.

CD31 staining in epithelioid sarcoma

We report an unusual case of epithelioid sarcoma. The tumour occurred in the finger of a 27-year-old female. The clinical history, histology and the electron microscopy of the lesion were typical for epithelioid sarcoma. However, immunohistochemical analysis showed strong membranous CD31 staining, a finding hitherto not described. All other robust vascular markers, including factor-VIII-related antigen (FVIIIrag) were negative. The findings were compared with the available literature data, leading us to conclude that there is insufficient evidence for endothelial derivation of epithelioid sarcoma, but in the differential diagnosis with vascular tumours CD31 may stain and to rule out angiosarcoma FVIIIrag is a useful antibody.

Primary epithelioid sarcoma of the dura: case report

OBJECTIVE AND IMPORTANCE

Epithelioid sarcomas are rare mesenchymal neoplasms that occur most often in the extremities of young adults. Despite isolated reports of epithelioid sarcomas arising in the head and neck region, these lesions have not been described previously, to our knowledge, in the central nervous system.

CLINICAL PRESENTATION

We present the case of an 18-year-old woman with a unique dural sarcoma that arose in the right frontotemporal region. As visualized on magnetic resonance imaging studies, the 4.5-cm tumor focally traversed the cranium to penetrate the galea, the temporal muscle, and subcutaneous tissue. No brain invasion was noted.

INTERVENTION

Despite gross total removal and postoperative radiotherapy (59 Gy), a large recurrence was noted 5 months after surgery. Histologically, the partly necrotic tumor consisted of epithelioid and spindle cells showing widespread vimentin and variable cytokeratin as well as epithelial membrane antigen immunoreactivity. Ultrastructurally, the cohesive cells featured various organelles, intermediate filaments, junctions, and filopodia-containing intercellular spaces.

CONCLUSION

With the inclusion of epithelioid sarcoma, the spectrum of central nervous system sarcomas continues to expand.

Proximal-type epithelioid sarcoma: a clinicopathologic study of 20 cases

We studied the clinicopathologic and immunohistochemical features of 20 cases of proximal-type epithelioid sarcoma to identify prognostic factors. The 20 patients ranged in age from 13 to 80 years (mean, 40 y); 12 patients were male and 8 were female. The tumors presented as deep soft-tissue or subcutaneous masses on the inguinal region in five, the thigh in four, the vulva in three, the axilla in three, and one each in the flank, chest wall, back, hip and perineum. The tumors ranged from 2 to 16 cm at their greatest diameter (mean: 7.8 cm). Histologically, 12 tumors (60%) were classified as the large-cell subtype, characterized by sheets of large cells with prominent nucleoli resembling poorly differentiated carcinoma, and a frequent rhabdoid phenotype, six (30%) were classified as the conventional subtype, and two (10%) as the angiomatoid subtype. The numbers of tumors exhibiting immunoreactivity for various markers were: vimentin (20 cytokeratin (20 [100%]); epithelial membrane antigen (17 [85%]); CD34 (9 [45%]); CD99 (5 [25%]); muscle markers, either desmin or alpha-smooth muscle actin (3 [15%]), other markers such as S-100 protein, neurofilament, neuron-specific enolase, synaptophysin and CD56 (12 [60%]); and p53 (16 [80%]). Fourteen lesions (70%) exhibited an MIB-1 index of 30% or more and, by a system of histologic grading using the MIB-1 score, 16 tumors (80%) were classified as high-grade (Grade 3). Thirteen patients (65%) developed local recurrence and 15 (75%) had metastases, primarily to the lymph nodes. At the last follow-up, 13 patients (65%) had died of their disease. A large tumor size and early metastasis were independently associated with a poor outcome. We conclude that proximal-type epithelioid sarcomas are rare, undifferentiated soft-tissue sarcomas of adults, with epithelioid features and a frequent rhabdoid phenotype. These tumors, when arising in proximal locations, have a much worse prognosis than those arising in distal locations.

Epithelioid sarcoma: an immunohistochemical analysis of 112 classical and variant cases and a discussion of the differential diagnosis

Epithelioid sarcoma (ES) is a distinctive soft tissue neoplasm with a predilection for the distal extremities of young adults. This tumor typically contains nodular aggregates of epithelioid and spindle cells with zonal necrosis. The neoplastic cells are generally reported to coexpress keratin and vimentin and are often stated to be positive for CD34. However, there is no large series with extensive immunohistochemical data, there are few data with regard to expression of different keratin subtypes, and there are no large series discussing the epithelioid sarcoma subtypes. In the current study, we immunohistochemically evaluated 88 typical and 24 variant (8 angiomatoid, 9 large cell/rhabdoid, and 7 "fibroma-like") ESs. Nearly all ESs with typical histology (94%) were positive for keratin 8 (K8), whereas 72% were positive for K19, 48% for intermediate- and high-molecular-weight keratins (34betaEH12), and 22% for K7; reactivity with the latter two antibodies was usually seen in only a minority of tumor cells. Vimentin reactivity was present in all cases, EMA in 96% of cases and muscle-specific actin and CD34 were noted in 41% and 52% of the cases, respectively. A few ESs (7%) showed focal cytoplasmic CD31 reactivity, but none exhibited a distinctive membrane staining pattern, and examples tested for FVIIIRAg were negative. The angiomatoid, fibroma-like, and large cell-rhabdoid ES variants had immunohistochemical profiles similar to the classic cases, supporting a common pathogenesis. Although not consistently expressed in ES, the presence of CD34 is helpful in distinguishing this entity from primary and metastatic carcinomas and other sarcomas such as malignant rhabdoid tumor.

Allelic loss on chromosome 22q in epithelioid sarcomas

Epithelioid sarcomas are soft tissue tumors with an indolent, but potentially aggressive, clinical behavior. Distinction from other benign and malignant entities may be a diagnostic dilemma. In this study, we evaluate the presence of loss of heterozygosity (LOH) of chromosome 22q in tumor DNA from 13 epithelioid sarcomas, four epithelioid angiosarcomas, and two epithelioid hemangioendotheliomas, and investigate its possible role in diagnosis. LOH was detected in 6 of 10 (60%) of the informative epithelioid sarcomas. No allele loss was detected in the informative vascular tumors, three angiosarcomas, and two hemangioendotheliomas. Chromosome 22q carries the locus of a tumor suppressor gene, the neurofibromatosis 2 (NF2) gene, which has been shown to be lost or mutated in some NF2-related tumors, sporadic meningiomas, and vestibular schwannomas, as well as a few other tumors. Our data suggest that a region of chromosome 22q may be the locus of a tumor suppressor gene involved in the tumorigenesis of these neoplasms. Genetic alterations of yet-unknown tumor suppressor genes in this region, or even the NF2 tumor suppressor gene, may play a role in epithelioid sarcomas tumorigenesis. The fact that LOH was only detected in epithelioid sarcomas and not in the vascular tumors studied suggests a possible role for this marker in diagnosis.

Angiosarcoma of soft tissue: a study of 80 cases

The clinicopathologic, immunohistochemical, and ultrastructural features of soft tissue angiosarcomas are not well defined. Eighty cases of angiosarcoma that involved the deep subcutis, skeletal muscle, retroperitoneum, mesentery, and mediastinum are reported. The lesions occurred in 50 male and 30 female patients who were 5-97 years of age; the peak incidence was in the seventh decade of life. A variety of associated conditions were documented in 20 of these cases, including a history of other neoplasms (some irradiated), synthetic vessel grafts, heritable conditions, and prior trauma or surgery. The angiosarcomas occurred in the extremities (n = 43 cases), trunk (n = 28), and the head and neck (n = 9) regions, with the thigh and the retroperitoneum being the most common sites. They often were characterized as enlarging, painful masses of several weeks' duration and were occasionally associated with acute hemorrhage, anemia, or a coagulopathy. The tumors measured 1-15 cm in diameter (median 5 cm) and frequently were hemorrhagic and multinodular. There was a wide morphologic spectrum within and between cases, including areas similar to cavernous and capillary hemangioma, Dabska tumor, spindle cell and epithelioid hemangioendothelioma, various spindle cell sarcomas, or carcinoma. Histologically, epithelioid angiosarcoma was the most frequently observed pattern; 70% of cases had epithelioid cells that were arranged in nests, clusters, papillae, and gaping vascular channels. Hemorrhage tended to obscure the diagnosis in several cases and often was associated with papillary endothelial hyperplasia-like areas. All 42 cases studied immunohistochemically stained at least focally for Factor VIII-related antigen, and nearly all stained strongly for vimentin, which accentuated the endothelial cells and vessel lumen formation. CD34 antigen was detected in 74% of cases, BNH9 in 72%, and cytokeratins in 35%. Epithelial membrane antigen, S-100 protein, and HMB45 were not detected. Fifty-five percent of the tumors had intracytoplasmic aggregates of laminin. Immunostains for alpha-smooth muscle actin demonstrated a prominent pericytic component in several tumors (24%). Ki67 immunostains with MIB1 indicated high proliferative activity (> or =10%) in 72% of cases. p53 immunoreactivity (>20% nuclear staining) was observed in 20% of cases. Ultrastructural studies performed on poorly differentiated areas of 12 cases showed groups of cells, which were frequently epithelioid, surrounded by basal lamina, and closely associated with pericytes, along with intercellular and intracellular lumina with or without red blood cells. Whorls of abundant intermediate filaments, occasional tonofilamentlike structures, and pinocytotic vesicles also were noted. In contrast to the findings of others, Weibel-Palade bodies were not seen. Follow-up in 49 cases (61%) showed that 53% of patients were dead of disease at a median interval of 11 months, whereas 31% had no evidence of disease at a median interval of 46 months. The remaining patients were either alive with disease (14%) or alive but disease status was unknown (2%). There were local recurrences in 20% of cases and distant metastases in 49%, most frequently to the lungs, followed by the lymph nodes, soft tissues, bone, liver, and other sites. These results indicate that angiosarcoma of soft tissue is a high-grade sarcoma. Older patient age, tumor location in the retroperitoneum, and larger tumor size as well as detection of MIB1 in > or =10% of the tumor cell population were all associated with a poorer prognosis.

Epithelioid sarcoma of the tongue

A case of epithelioid sarcoma in the tongue is reported. The patient, a 35 year old woman, presented with a non-ulcerated painful lesion of the tongue. Microscopically, the tumour was characterised by multiple coalescent nodules with central geographic necrosis infiltrating the lingual muscle. The tumour cells were epithelioid with abundant eosinophilic cytoplasm and atypical nuclei. Immunohistochemically, the tumour cells stained for vimentin, keratin, and epithelial membrane antigen. These morphological and immunohistochemical appearances led to the diagnosis of epithelioid sarcoma of the tongue. Seven years later, the patient died with metastatic dissemination to the scalp, lungs, and brain. No case of epithelioid sarcoma arising in the tongue has been described previously.

"Proximal-type" epithelioid sarcoma, a distinctive aggressive neoplasm showing rhabdoid features. Clinicopathologic, immunohistochemical, and ultrastructural study of a series

Eighteen examples of an unusual malignant soft-tissue neoplasm, the morphology of which ranged from that of "atypical" epithelioid sarcoma to that of a rhabdoid tumor or undifferentiated carcinoma (with transitional forms) are described. Patients included 11 males and seven females; their median age was 35.5 years with most patients aged 20 to 40 years. Development of a mass was the main presenting symptom. Six tumors developed in the pelvis and perineal region, four in the pubic region and vulva, three in the buttocks, one in the deep soft tissues of the left hip, one on the penis, one in left forearm, one in left axilla, and one on the occiput. Tumor size ranged from 1 to 20 cm (median, 4 cm). On microscopic examination, the tumor cells invaded the subcutaneous or deep soft tissues, had prominent epithelioid or rhabdoid features, had marked cytologic atypia, and grew in a multinodular pattern in half of the cases. Areas of necrosis were often seen. A granuloma-like pattern reminiscent of that observed in classic epithelioid sarcoma was observed in only two cases. Immunohistochemically, positivity for cytokeratin, epithelial membrane antigen, and vimentin was seen in all but one of the cases. Of 16 cases, 10 and eight tumors reacted with desmin and CD34, respectively; five of 15 reacted at least focally with smooth-muscle actin, whereas three of 13 and one of 10 reacted for HMB-45 and carcinoembryonic antigen, respectively. S-100 protein and CD31 yielded negative results. Seven tumors were investigated at the ultrastructural level, four of which showed prominent intracytoplasmic intermediate filament aggregates, often accumulating into paranuclear whorls, which is in keeping with the rhabdoid phenotype. Five tumors showed features of epithelial differentiation (i.e., tonofilament-like structures or desmosomes or both), whereas one tumor displayed features of myofibroblastic differentiation. Differential diagnoses include mainly conventional epithelioid sarcoma, extrarenal malignant rhabdoid tumor, epithelioid malignant peripheral nerve sheath tumor, melanoma, rhabdomyosarcoma, and undifferentiated carcinoma. Follow-up information on 14 patients (range, 4 months to 8 years; median, 19 months) revealed local recurrence in one case and metastatic dissemination in six patients, leading to death in five. In our opinion, the above-described neoplasms represent a usually "proximal-type" of epithelioid sarcoma. In contrast to the conventional, "distal-type" epithelioid sarcoma, the proximal variant is characterized by a predominantly large-cell, epithelioid cytomorphology, marked cytologic atypia, frequent occurrence of rhabdoid features, and lack of a granuloma-like pattern in most cases. It appears to be somewhat more aggressive (or at least metastasizes earlier) than usual epithelioid sarcoma.

Cutaneous epithelioid angiosarcoma: a potential diagnostic trap for cytopathologists

We report on the cytologic features of a rare case of cutaneous epithelioid angiosarcoma of the scalp occurring in a 65-yr-old Chinese male. The prominent epithelioid features may cytologically mimic poorly-differentiated carcinoma, malignant melanoma, and even epithelioid sarcoma. Recognition of subtle cytologic features of vasoproliferation, immunohistochemical demonstration of endothelial markers, and ultrastructural examination are necessary before a final conclusion may be drawn.

Vascular leiomyoma in an index finger undergoing malignant transformation

We report a case of vascular leiomyoma of the pulp of the index finger that recurred twice and underwent malignant change. Ray resection proved to be curative. An extensive literature review is given.

Epithelioid sarcoma in FNAB smears

FNAB smears of eleven epithelioid sarcomas were reviewed and analysed. Ten cases had a very similar cytomorphologic picture composed predominantly of dissociated epithelioid-like cells with eccentrically placed nuclei. These tumors were clearly malignant but difficult to differentiate morphologically from melanoma, epithelioid leiomiosarcoma, and Schwannoma or adenocarcinoma. One case was composed of spindle cells and was reminiscent of a fibrohistiocytic tumor. Immunocytochemical reactions to vimentin and cytokeratin were performed in six cases on the Papanicolaou stained smears. The reactions to both antigens were positive in all six cases. Ultrastructural characteristics of eight of the tumors are also described. It seems that epithelioid sarcoma has a rather distinct cytomorphologic picture. Taking into consideration clinical data and using also immunocytochemistry, a definitive diagnosis of epithelioid sarcoma can probably be given from FNAB smears.

Cutaneous epithelioid angiosarcoma: a clinicopathological study of four cases

Four cases of cutaneous epithelioid angiosarcoma are described together with the potential diagnostic trap of mistaking these tumours for poorly differentiated carcinoma or malignant melanoma. The immunophenotypic profile using four endothelial markers showed positive staining in all cases for factor VIII related antigen in a predominantly paranuclear dot-like fashion and for CD31 (JC70); in three cases for CD34 (QB-END/10) and in two cases with UEA-1. All four cases were cytokeratin (CAM 5.2 and AE1/AE3) negative in contrast to the positive staining reported at non-cutaneous sites. Aberrant S-100 protein expression was seen in one case. In two cases subsequent recurrences showed better differentiation than the original tumour. Electronmicroscopy confirmed the absence of non-endothelial lines of differentiation but failed to reveal Weibel-Palade bodies.

Epithelioid sarcoma: an electron-microscopic, immunohistochemical and DNA flow cytometric analysis

Eight epithelioid sarcomas (ES) were studied by electron microscopy, immunohistochemistry, and DNA flow cytometry. Ultrastructurally, the tumour cells showed desmosome-like intercellular junctions and numerous microvilli, in addition to whorled arrangements of intermediate filaments. Tumour cells were positive for epithelial membrane antigen, cytokeratin, and vimentin, and negative for carcinoembryonic antigen and desmin. All seven cases examined by flow cytometry showed diploid or hyperploid (near diploid) DNA content. This seems to correspond to the relatively long clinical course and low-grade malignant nature of ES. Although the histogenesis of ES is still uncertain, the results of this study suggest that it is a tumour of primitive mesenchymal cells with the capacity to show epithelial differentiation.