Epithelioid hemangioma of bone

Primary vascular tumors of bone: A comprehensive literature review on classification, diagnosis and treatment

Primary vascular tumors of bone are a heterogeneous group of neoplasms, ranging from benign hemangiomas to frankly malignant epithelioid hemangioendotheliomas and angiosarcomas. Over the years, their classification has been a matter of discussion, due to morphologic similarities and uncertainty regarding biologic behavior. Over the past decade, with the development of next-generation sequencing, there has been a significant improvement in the molecular characterization of these lesions. The integration of their morphologic, immunohistochemical and molecular features has led to a better stratification, with important prognostic and therapeutic implications. Nevertheless, primary vascular bone tumors still represent a challenge for medical oncologists. Given their rarity and heterogeneity, in the last few years, there has been no significant progress in medical treatment options, so further research is needed. Here we present a review of the current knowledge regarding primary vascular tumors of the bone, correlating clinicopathologic features with tumor behavior and therapeutic approaches.

A Rare Case of Primary Epithelioid Hemangioma of Bone with WWTR1::FOSB Fusion: A Benign Lesion with the Potential to Mimic Malignancy

Epithelioid hemangioma of bone is a rare benign, locally aggressive vascular tumor that can be particularly challenging to diagnose given its frequent multifocality, non-specific imaging findings, and wide range of morphologic appearances. Additionally, some epithelioid hemangiomas demonstrate atypical histologic features including increased cellularity, necrosis, and moderate cytologic atypia - characteristics that may raise concern for malignancy. Molecular studies can serve as a powerful, objective tool in the differential diagnosis of diagnostically challenging epithelioid vascular tumors. Importantly, FOS and FOSB gene rearrangements have been identified as the genetic hallmarks of osseous epithelioid hemangioma, present in greater than 70% of cases. FOSB-fusion-positive epithelioid hemangioma, in particular, may display atypical histologic features. While ZFP36 is the typical FOSB fusion partner in epithelioid hemangioma, we herein present a case of epithelioid hemangioma of bone with a rare WWTR1::FOSB fusion. This case demonstrates the diagnostic challenges associated with epithelioid hemangioma, especially in the setting of FOSB gene rearrangements, and the importance of genomic studies in the work up of these vascular tumors.

Epithelioid Haemangioma of Bone: A Case Series and Comprehensive Literature Review Reappraising the Diagnostic Classification of All Epithelioid Vascular Neoplasms of Bone

Epithelioid vascular neoplasms of the bone are classified by the World Health Organization (WHO) into only two tiers: low-grade epithelioid hemangioma (EH) and a more malignant category including both epithelioid hemangioendothelioma and epithelioid angiosarcoma. The World Health Organization defines bone EH as a locally aggressive neoplasm with no connotation of benign or intermediate malignancy. We reviewed three cases of EH in our lab archives with the perspective of appraising their histomorphological approach toward diagnosis. Patients were in the age range of 15-25 years. The site of the neoplasms ranged from the carpal bones to the metatarsal bones. Histomorphological examination of the lesions showed a nodular growth pattern of a vascular neoplasm without demonstrable vessel origin. The vasoformative area increased from the center to the periphery, with prominent epithelioid morphology of the endothelial cells at the periphery and an associated inflammatory infiltrate comprising eosinophils, lymphocytes, and plasma cells. The growth pattern was diffuse, with extension into the deeper dermis of overlying skin.

Epithelioid hemangioendothelioma of bone: A survival analysis of 50 cases from the SEER database (1992-2016)

Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor that may arise in bone. The purpose of this investigation was to determine the clinicopathological features and outcomes of osseous EHE in a large patient series, and to assess whether survival is impacted by demographics, tumor characteristics, or treatment factors. This was a retrospective review of the Surveillance, Epidemiology and End Results (SEER) database from 1992 to 2016. Kaplan-Meier was used to estimate overall survival (OS) and disease-specific survival (DSS). A Cox regression model was used to identify prognostic factors. Fifty patients from 1992 to 2016 with a median age of 54.5 years (IQR, 37–67) were reviewed. For location, 46% (n = 23) of tumors arose from the appendicular skeleton while 38% (n = 19) occurred within the axial skeleton (overlapping EHE: 16%, n = 8). Of the cases with recorded treatment factors, 54.8% (n = 23) had surgery, 26% (n = 13) received radiation, 22% (n = 11) were treated with chemotherapy, and 26% (n = 13) had surgery plus radiation. The 5-year OS probability was 49.2% (95% CI, 23.6–70.6), and the 5-year DSS probability was 63.9% (95% CI, 33.0–83.5). No surgery (surgery: HR, 0.262; 95% CI, 0.07–0.9); p = 0.041) and age older than 50 years (HR, 4.117; 95% CI, 1.1–15.4; p = 0.035) were negative prognostic factors of disease-specific mortality after controlling for confounding variables. There was no association between disease-specific mortality and adjuvant or multimodal therapy. The prognosis of EHE of bone is less than favorable, and the 5-year DSS probability of 64% emphasizes the intermediate grade nature of this tumor subtype. Surgical treatment, when feasible, is associated with a better prognosis.

Epithelioid Hemangioendothelioma and Epithelioid Hemangioma: Pazopanib as a Potential Salvage Therapy

Epithelioid hemangioma (EH) and epithelioid hemangioendothelioma (EHE) are both rare vascular tumors. EH tumors are often benign while EHE tumors have moderate malignant potential. Here, we present three unique cases at Soroka Medical Center, two featuring EH of the bone and one presenting EHE of the mediastinum. Each case demonstrates distinct treatment challenges due to the rarity of both diseases and lack of established guidelines. We propose three treatment approaches including pazopanib for salvage therapy of EH of the bone and minimally invasive surgical resection which in these cases lead to complete symptom relief and tumor stabilization upheld over time with close follow-up.

Secondary aneurysmal bone cysts and associated primary lesions: imaging features of 49 cases

PURPOSE

To describe the imaging, anatomic, and clinical features of a series of secondary aneurysmal bone cysts (ABC) and to ascertain their most commonly associated primary bone lesions.

METHODS

Forty-nine cases of histopathologically proven secondary ABCs were retrospectively reviewed. Demographic data and clinical history were obtained. Radiographic, computed tomographic, magnetic resonance, and nuclear medicine imaging were analyzed. Lesion location, imaging characteristics, and associated primary lesions were documented. Linear regression analysis and Chi-squared testing was performed for statistical analysis.

RESULTS

Twenty-four males and 25 females were included, with an age range of 8-79 years (mean 29.7 + - 4.5 years). Eleven types of primary bone lesion were identified, with giant-cell tumor (n = 17, 35%), chondroblastoma (n = 11, 22%), fibrous dysplasia (n = 6, 12%), osteoblastoma (n = 4, 8%) and osteosarcoma (n = 4, 8%) being the most frequent. The lesions involved chiefly the long bone epiphyses (n = 25, 51%). Secondary ABC imaging findings and locations most closely approximated those of their primary counterparts, although fluid-fluid levels were seen at a higher frequency than previously reported in primary chondroblastoma (9/11, 82%), fibrous dysplasia (2/6, 33%), osteoblastoma (4/4, 100%), osteosarcoma (3/4, 75%), and chondromyxoid fibroma (1/2, 50%).

CONCLUSION

The most common primary lesions associated with secondary ABC were giant cell tumor and chondroblastoma, located in the long bone epiphyses. The majority of the secondary ABCs demonstrate predominant imaging characteristics typical of the primary bone lesions, but with a higher presence of fluid-fluid levels.

Epithelioid Vascular Tumors: A Review

Vascular tumors are a diagnostically challenging area. This is particularly true in the case of epithelioid vascular tumors. Not only is the distinction between different epithelioid vascular tumors challenging, but also the differential diagnosis may be substantially expanded by the inclusion of melanoma, carcinomas, and other epithelioid soft tissue tumors. Recently developed immunohistochemical markers and more comprehensive genetic characterizations continue to advance our understanding of epithelioid vascular tumors. The present paper briefly reviews and updates basic concepts with regard to the following epithelioid vascular tumors: epithelioid hemangioma, epithelioid angiomatous nodule, pseudomyogenic hemangioendothelioma, composite hemangioendothelioma, epithelioid hemangioendothelioma, and epithelioid angiosarcoma.

Epithelioid hemangioma of the scapula treated with chemoembolization and microwave ablation: Α case report

Bone epithelioid hemangiomas are classified within benign vascular tumours but are commonly misdiagnosed as low-grade angiosarcomas or epithelioid hemangioendotheliomas. Current therapeutic interventions include various treatment options but local recurrence or distal lymph node involvement has been reported. We report a rare case of scapular epithelioid hemangioma that was initially treated using a combination of chemoembolization and microwave ablation. This combination has not been previously reported in the literature regarding the management of this tumour. A year after the first course of treatment, the tumour size has been reduced more than 70% and the patient has remarkable clinical improvement. Results reported in this case study demonstrated that combination of chemoembolization and microwave ablation is a feasible, safe and effective technique in the treatment of bone epithelioid hemangiomas. Even if the tumour is still present afterwards, a substantially smaller surgical excision will be needed.

Epithelioid hemangioma of bone: radiologic and magnetic resonance imaging characteristics with histopathological correlation

BACKGROUND

Epithelioid hemangioma is a rare vascular tumor that can occur in soft tissues or bone. The tumor is part of a spectrum of vascular tumors that also includes epithelioid hemangioendothelioma and angiosarcoma. When involving the bone, the tumor usually involves the metaphysis or diaphysis of the long tubular bones and most commonly occurs in adults. It has been rarely reported in pediatric patients, and in these reported patients, the tumor primarily involves the epiphysis.

OBJECTIVE

To review three cases of epithelioid hemangioma of bone occurring in pediatric patients involving the epiphysis and to explore the imaging features of this tumor.

MATERIALS AND METHODS

Retrospectively review three cases of epithelioid hemangioma occurring in skeletally immature patients.

RESULTS

These tumors primarily involved the epiphyses or epiphyseal equivalent bones. One lesion was centered in the metaphysis but extended to the epiphysis. These are three cases presenting in an unusual location and at an unusual age.

CONCLUSION

Epithelioid hemangioma, though rare, can occur in pediatric patients and appears to involve the epiphyses in these patients. This is in contrast to the usual age and location reported. Epithelioid hemangioma may be considered for an epiphyseal lesion in a skeletally immature patient.

Primary Left Tibial Epithelioid Hemangioendotheliomas With Multiple Metastases Revealed by FDG PET/CT Imaging

Bone epithelioid angiosarcoma is an extremely rare osseous malignancy with an aggressive and destructive biological behavior. We present FDG PET/CT findings of a 59-year-old woman with left lower limb pain for 1 month. The images revealed abnormal activity in both left fibula and left tibia. In addition, abnormal activity in the sacrum and enlarged retroperitoneal lymph nodes was also noted. Pathological examination demonstrated bone epithelioid angiosarcoma.

Epithelioid hemangioma of bone: a report of two special cases and a literature review

Intraosseous epithelioid hemangioma (EH) is a rare intermediate vascular neoplasm, characterized by locally aggressive and rarely metastasizing behavior. Occasionally, EH of bone can behave strangely and may simulate malignant neoplasm. Here, we report two cases of EH of bone. Of interest was the fact that the computed tomography and magnetic resonance images from one case showed an osteolytic lesion in the right scapula, with multiple swollen lymph nodes in the right supraclavicular and axillary areas. Another patient exhibited a local recurrence in the cervical vertebrae. The initial radiological diagnosis of both cases was metastatic tumor. EH should be included in the differential diagnosis of a radiographic osteolytic lesion with an aggressive appearance. Also, we reviewed the literature that reported EH of bone and summarized their radiological appearances. The cases of EH of bone that exhibited involvement of regional or draining lymph nodes were also summarized.

Epithelioid Hemangioma of Bone: A Potentially Metastasizing Tumor?

The case of a 15-year-old boy with a severe swelling of the 2nd toe in the left foot and a large swelling of the left inguinofemoral region is described. Histologic examination of the foot lesion showed a typical epithelioid hemangioma of bone that extended into the soft tissues, with a secondary location in the groin, suggestive of lymph node involvement. Subsequently, imaging also revealed swelling of iliac and para-aortic lymph nodes, which probably indicates further lymph node spread.. Besides the fact that epithelioid hemangioma of the toe has not been reported yet, our case showed a noncontinuous localization, most likely in draining lymph nodes. This finding suggests metastatic disease, an event that is extremely rare for epithelioid hemangioma. As such, epithelioid hemangioma might be comparable to another benign vascular tumor, the retiform hemangioendothelioma, which occasionally metastasizes to the lymph nodes without systemic spread.

Epithelioid hemangioendothelioma of the proximal phalanx of the left second toe - a rare occurence

INTRODUCTION

Epithelioid hemangioendothelioma (EHE) of the bone is extremely rare and occurs predominantly in males. It most frequently occurs during the second and third decades of life. The lower extremities are most commonly involved. We describe a diagnostically challenging case of epithelioid hemangioendothelioma of proximal phalanx of 2nd toe of left foot with histological features reminiscent of osteoblastomatosis.

CASE REPORT

A 52 year old man presented with history of intermittent pain with swelling in second toe since 6 months. Radiograph showed a lytic lesion in proximal phalanx of the great toe. CT and MRI reported non specific lesion in the toe. Pain was quite severe and as the patient was a labourer and wanted to get back to his work as soon as possible a decision of disarticulation of the second toe at metatarsophalnageal joint was taken. Histopathology confirmed the diagnosis of Epithelioid hemangioendothelioma and patient was called for regular follow up. There are no complications and recurrence at two year follow up.

CONCLUSION

EHE of the bone is extremely rare vascular tumor. To our knowledge, this is the first case of EHE with such features. EHE should be kept as one of the important differential diagnosis while diagnosing vascular tumors. Careful attention to the histopathological features is necessary for the confirmation of the diagnosis.

Imaging findings of various talus bone tumors-clinico-radiologic features of talus bone tumors

Osseous neoplasms of the foot are uncommon, accounting for only 3.3% of all primary bone tumors. Bone tumors of the talus are even rarer, and there are not many publications that comprehensively evaluate the imaging findings of talus tumors. The purpose of this article is to review the benign and malignant bone tumors affecting this uncommon site and to describe the clinical and radiologic features of each tumor.

Epithelioid hemangioma of the spine: Two cases

We report two cases of epithelioid hemangioma (EH) manifested in the thoracic spine with associated clinical, radiographic, and pathological findings. Epithelioid hemangioma is a benign vascular tumor that can involve any bone (including the spine in a subset of patients). Although recognized as a benign tumor by the WHO, it can display locally aggressive features. Within the spine, these features may lead to pain, instability, and/or neurologic dysfunction. The radiographic appearance is most typically that of a lytic, well-defined lesion on plain film or CT. The MRI appearance is typically hypointense on T1WI, hyperintense on T2WI, and avidly enhancing, often with an extraosseous soft-tissue component.

Epithelioid angiosarcoma of the spine: A case report of a rare bone tumor

Epithelioid angiosarcoma (EA) is an extremely rare subtype of angiosarcoma, which is characterized by large cells with an epithelioid morphology. EA typically arises in deep soft tissues, including the adrenal gland, skin and thyroid, however, EA rarely arises in the spine. The current study presents a case of osteolytic lesions involving the fourth lumbar (L4) level of the spine. Preoperatively, the patient was misdiagnosed with metastatic carcinoma, however, a radiological examination detected the presence of osteolytic or destructive lesions in the vertebrae, which extended into the pedicles. Histopathological and immunohistochemical evaluations were performed on the tumor tissue obtained from a decompression specimen of the L4 vertebra. A bone lesion composed of sheet-like malignant cells exhibiting atypical epithelioid morphology with vascular formation was observed. The presence of anastomosing vascular channels lined by epithelioid endothelial cells also indicated that focal endothelial differentiation had occurred. In addition, immunohistochemistry assays revealed that the lesion was positive for the endothelial cell markers, CD31, CD34 and vimentin. The tumor was treated with decompression of the L4 vertebra, followed by posterior stabilization. The patient subsequently refused chemotherapy and radiotherapy but completed six months of follow-up. At the time of writing, the tumor remains under control and the patient is asymptomatic. This case highlights the difficulty of diagnosing EA, which requires careful pathological examination and immunophenotype labeling. At present, CD31 is the most sensitive marker for detecting EA.

"Soap Bubble" Lesion of the Middle Phalanx: Enchondroma or Epitheloid Hemangioma

Introduction:

Epitheloid hemangioma, a benign vascular tumor that arises in skin and soft tissues can also involve the skeletal system. Occasionally this has been reported from small tubular bones of the hand.

Case Report:

Authors report a case of epitheloid hemangioma of the middle phalanx in a young girl without any cutaneous manifestations. The lesion presented as a swollen middle finger, and plain radiographs showed a geographic area of destruction with cortical thinning and intra lesional calcifications. The case was managed by curettage and bone grafting. Histology confirmed this as a case of epitheloid hemangioma.

Conclusion:

Epitheloid hemangioma should be considered in the differential diagnosis of hand masses with expansile lytic lesions with cortical thinning.

An unusual case of cavernous hemangioma of the rib in a young man with lung tuberculosis: a brief review and case report

Hemangiomas are benign vascular tumors that usually involve the liver, skin, eyes and central nervous system. Hemangioma of the bone is unusual and is generally observed in the vertebrae or skull while hemangioma of the costae is extremely rare. Hemangioma of the rib and chest wall tuberculosis may be misdiagnosed as chest wall tumors. We herein report a case of hemangioma of the rib with a tuberculosis infection of the pleura.

Vascular bone tumors: a proposal of a classification based on clinicopathological, radiographic and genetic features

The classification of vascular bone tumors remains challenging, with considerable morphological overlap spanning across benign to malignant categories. The vast majority of both benign and malignant vascular tumors are readily diagnosed based on their characteristic histological features, such as the formation of vascular spaces and the expression of endothelial markers. However, some vascular tumors have atypical histological features, such as a solid growth pattern, epithelioid change, or spindle cell morphology, which complicates their diagnosis. Pathologically, these tumors are remarkably similar, which makes differentiating them from each other very difficult. For this rare subset of vascular bone tumors, there remains considerable controversy with regard to the terminology and the classification that should be used. Moreover, one of the most confusing issues related to vascular bone tumors is the myriad of names that are used to describe them. Because the clinical behavior and, consequently, treatment and prognosis of vascular bone tumors can vary significantly, it is important to effectively and accurately distinguish them from each other. Upon review of the nomenclature and the characteristic clinicopathological, radiographic and genetic features of vascular bone tumors, we propose a classification scheme that includes hemangioma, hemangioendothelioma, angiosarcoma, and their epithelioid variants.

Epithelioid hemangioma of bone and soft tissue: a reappraisal of a controversial entity

BACKGROUND

The controversy surrounding diagnosis of an epithelioid hemangioma (EH), particularly when arising in skeletal locations, stems not only from its overlapping features with other malignant vascular neoplasms, but also from its somewhat aggressive clinical characteristics, including multifocal presentation and occasional lymph node involvement. Specifically, the distinction from epithelioid hemangioendothelioma (EHE) has been controversial. The recurrent t(1;3)(p36;q25) chromosomal translocation, resulting in WWTR1-CAMTA1 fusion, recently identified in EHE of various anatomic sites, but not in EH or other epithelioid vascular neoplasms, suggests distinct pathogeneses.

QUESTION/PURPOSES

We investigated the clinicopathologic and radiologic characteristics of bone and soft tissue EHs in patients treated at our institution with available tissue for molecular testing.

PATIENTS AND METHODS

Seventeen patients were selected after confirming the pathologic diagnosis and fluorescence in situ hybridization analysis for the WWTR1 and/or CAMTA1 rearrangements. Four patients had multifocal presentation. Most patients with EH of bone were treated by intralesional curettage. None of the patients died of disease and only four patients had a local recurrence.

RESULTS

Our results, using molecular testing to support the pathologic diagnosis of EH, reinforce prior data that EH is a benign lesion characterized by an indolent clinical course with an occasional multifocal presentation and rare metastatic potential to locoregional lymph nodes.

CONCLUSION

These findings highlight the importance of distinguishing EH from other malignant epithelioid vascular tumors as a result of differences in their management and clinical outcome.

LEVEL OF EVIDENCE

Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Epithelioid hemangioma of the distal humerus with pathologic fracture

Epithelioid hemangioma is a rare tumor that can have bone involvement. Its clinically and radiographically aggressive appearance mimics a malignant neoplasm. Although epitheliod hemangioma has been described as having an aggressive appearance on magnetic resonance imaging (MRI) and plain radiographs, this is the first reported case of pathologic fracture associated with this lesion to our knowledge. This article describes a case of epithelioid hemangioma involving the distal humerus, which initially presented with progressive pain and fracture of the lateral condyle. The aggressive appearance on plain radiographs and MRI suggested a malignant bone tumor. This preliminary diagnosis was confirmed due to the presence of local lymph node spread on positron emission tomography/computed tomography. After a core needle biopsy revealed nondiagnostic tissue, rather than performing a wide resection based on a presumptive malignant diagnosis, we followed the standard diagnostic algorithm and performed an open biopsy with temporary internal stabilization. The tissue sample was adequate and revealed a diagnosis of epithelioid hemangioma. Based on this finding, we were able to proceed with surgical management, including curettage of the lesion, placement of a bone graft, and internal fixation, rather than a wide resection with elbow joint replacement. This article emphasizes the need for careful adherence to the diagnostic algorithm for musculoskeletal tumors. In doing so, a definitive diagnosis was reached, and our patient was able to resume his occupation as a laborer without the restrictions that would have accompanied elbow arthroplasty.

Epithelioid hemangioma involving three contiguous bones: a case report with a review of the literature

An epithelioid hemangioma involving three contiguous bones in continuity has, to the best of our knowledge, not been reported in the literature. A case of a 48-year-old man presented with radiating pain to the lower thoracic region for two years. A radiograph and CT scan revealed both permeative osteolytic and multiple trabeculated lesions involving the left posterior part of the 10th rib as well as the 9th and 10th vertebral bodies in continuity and was misled as a malignant or infectious lesion. The histopathology and immuno-histochemistry of the lesion confirmed the diagnosis of an epithelioid hemangioma. The lesion was still stable as of three years after surgery.

Multicentric epithelioid angiosarcoma of the spine: a case report of a rare bone tumor

BACKGROUND CONTEXT

Epithelioid angiosarcoma (EA) is a high-grade sarcoma of vascular origin. EA is a rare variant of angiosarcoma. It is characterized by large cells with an epethelioid morphology. EA has been reported in sites like skin thyroid, adrenal gland, soft tissue, and rarely in bone.

PURPOSE

The current article describes a case of multicentric EA of the spine that presented simultaneously at T4 spine and the posterior one third of the left fourth rib. STUDY DESIGN/SETTINGS: This study included a patient with a rare spinal tumor, which presented insidiously. Radiologically, the lesions were osteolytic with erosion of cortices. The tumor was composed of nests and cords of malignant cells with epithelioid morphology with areas of vascular differentiation, necrosis, and hemorrhage. Anastomosing vascular spaces lined by epithelioid endothelial cells suggested focal endotheliod differentiation.

METHODS

Histopathological evaluation of the tumor obtained from en bloc resection of the fourth rib and specimen from decompression of the fourth thoracic vertebra was done. Immunohistochemistry showed positivity for endothelioid cell markers like CD31 and factor VIII related antigen. The authors point out the need for immunohistochemical evaluation after careful histological analysis for vascular differentiation for an accurate diagnosis of vascular bone tumors with epithelioid features so that an erroneous diagnosis of metastatic carcinoma can be avoided. EA occurs rarely in bone. EA is marked by the presence of large polygonal epithelioid malignant cells with marked cellular atypia and pleomorphism. The arrangement of the cells may mimic epithelial neoplasm. These types of lesions are a definite diagnostic challenge in bone biopsy. The tumor was treated with en bloc resection of the rib and decompression of the body of T4 spine, followed by megavoltage radiotherapy. Follow-up X-rays showed regression of the tumor at 2 years. CD31 is the most sensitive marker for EA. Even in the absence of obvious vascular differentiation, abundant intratumoral hemorrhage and intratumoral neutrophils are definite morphologic changes that should suggest a vascular origin.

RESULTS

The patient was followed up for 2 years. A conservative surgical approach with a radical course of megavoltage radiotherapy could yield a good result in EA of bone. At the time of writing this report, there is no evidence of tumor recurrence.

CONCLUSION

It is important to differentiate EA from other tumors because the clinical course and treatment are specific for these conditions. Careful histologic and immunohistochemical analysis will clinch the diagnosis. Even though rare, we stress the importance to be aware of the existence of this tumor, which is essential for correct diagnosis.

Epithelioid and spindle cell haemangioma of bone

A case of epithelioid and spindle cell haemangioma of bone occurring in the proximal femur is presented. The tumour had typical microscopic features with a striking lobular pattern comprising spindled and epithelioid areas with admixed inflammatory cells. The case represents only the eighth reported example of this rare tumour, which appears to fit in the spectrum of epithelioid haemangioma. This is the first case to involve the proximal portion of a long bone. A review of the classification and features of similar vascular tumours of bone is presented.

Epithelioid and Epithelial Neoplasms of Bone

Context.—Epithelioid and epithelial neoplasms seen in bone are rare and include epithelioid variants of vascular lesions, osteoblastoma, osteosarcoma, chordoma, and chondroblastoma as well as adamantinoma and metastatic carcinoma.

Objective.—To provide an overview of tumors with epithelioid histology and address the clinical context and diagnostic issues.

Data Sources.—Pertinent literature is reviewed with emphasis on recent and controversial issues.

Conclusions.—The differential diagnosis in epithelioid/ epithelial lesions of bone is limited. The primary consideration in many cases is distinguishing primary from metastatic lesions.

Intraosseous haemangioma of the proximal femur: imaging findings

Haemangiomas of bone are uncommon lesions, accounting for approximately 1% of all primary bone tumours. The most frequent sites of involvement are the calvaria and the vertebral column. When haemangiomas involve long tubular bones, they are usually found in the diaphysis or metadiaphysis. Juxta-articular or epiphyseal location for a long bone haemangioma is rare. We present the imaging findings in a case of a histopathologically proven juxta-articular intraosseous haemangioma of the proximal femur. We believe ours is the first report of a haemangioma involving the proximal end of the femur.

Epithelioid angiosarcoma of the bone: a series of 10 cases

The clinical and pathologic features of 10 epithelioid angiosarcomas of bone were analyzed. There were eight males and two females who ranged in age from 26 to 83 years (mean 62 years). Four tumors were solitary and six were multifocal. In two consultation cases, the submitted diagnosis was metastatic carcinoma. Microscopically, the tumor cells were arranged in solid and infiltrative sheets, and in most cases vascular channels or cystically dilated spaces were present. The neoplastic cells had abundant eosinophilic cytoplasm and large nuclei with open chromatin and prominent eosinophilic nucleoli. Intratumoral hemorrhage, neutrophilic infiltrates, and intracytoplasmic lumina were frequently present. All 10 tumors stained positive for one or more endothelial markers, with CD31 being the most sensitive marker. Seven cases stained positive for cytokeratin. Ultrastructural examination in three tumors confirmed their endothelial differentiation. In the absence of obvious vascular differentiation, abundant intratumoral hemorrhage and intratumoral neutrophils are useful ancillary morphologic features that may suggest a vascular origin. Six patients are dead of disease, one is alive with metastasis, and two patients are currently disease free. Epithelioid angiosarcoma of bone should be included in the differential diagnosis of epithelioid neoplasms of bone, and endothelial markers should be a part of their immunohistochemical analysis to avoid the misdiagnosis of a metastatic carcinoma because of the significant differences in the treatment and clinical outcomes of these entities.

Epithelioid vascular tumors of bone: a review and proposal of a classification scheme

Skeletal vascular tumors composed of epithelioid endothelial cells commonly result in diagnostic difficulty. Although tumors with this morphology have been recognized for many years, there is a considerable degree of confusion regarding their nomenclature and classification. In this article what is believed to represent the morphologic features of this family of tumors is outlined, the historical context of epithelioid endothelial tumors is briefly discussed, and pertinent literature and texts pertaining to the subject is reviewed. It is proposed that the osseous epithelioid endothelial tumors should be classified in a similar manner to their soft tissue counterparts and it is suggested that this approach should help to clarify the confusion surrounding this subject of surgical pathology.