Intraneural angiosarcoma and angiosarcoma arising in benign and malignant peripheral nerve sheath tumours: clinicopathological and immunohistochemical analysis of four cases

Ovarian angiosarcoma: A systematic review of literature and survival analysis

Ovarian angiosarcoma (OA) is rare, with only sporadic cases reported in English literature. We performed a systematic review of cases published in the PubMed, Science Direct, and Google Scholar databases with the aim of describing the reported clinicopathological features of OA. Fifty-three articles that reported 60 patients were reviewed. Of the 60 patients, 7 (11.6 %) were diagnosed with secondary (metastatic) ovarian angiosarcoma and 53 (88.3 %) were diagnosed with primary ovarian angiosarcoma. The mean age at presentation for ovarian angiosarcoma was 38.3±17.8 years. The average tumor size for ovarian angiosarcoma was 11.9±6.1 cm. Abdominal distention was reported in 45/60 (75 %). Microscopic examination revealed necrosis in 28/60 (46.7 %), pleomorphism in 32/59 (54.2 %), mitotic figures in 44/60 (73.3 %), spindle-shaped cells in 27/36 (75 %), epithelioid-shaped cells in 20/36 (55.5 %), and mixed epithelioid and spindle-shaped cells in 12/36 (33.3 %) patients. On immunohistochemistry CD 31 was positive in 41/41 (100 %), CD 34 in 38/39 (97.4 %), and Factor VIII related antigen in 18/21 (85.7 %) patients. Metastasis was present in 43/60 (71.6 %) patients. Chemotherapy and surgery was performed in 36/52 (69.2 %). The median follow-up time for ovarian angiosarcoma was 7 months (IQR1-IQR3:2-13.5 months). 24 (48 %) of the 50 patients with available survival data were alive and 26/50 (52 %) were dead of disease. Survival analyses (KM curves) revealed that the presence of necrosis (log-rank test; p = 0.05) and absence of spindle-shaped cells (log rank test; p = 0.04) on histopathology were associated with worse outcomes, while treatment with combined chemotherapy and surgical excision was associated with better survival (P < 0.001) therefore, prompt diagnosis and early treatment with combined chemotherapy and surgical excision can prolong survival in OA.

Angiosarcoma of gallbladder, a literature review

BACKGROUND

Angiosarcoma of the gallbladder is a rare diagnostic entity rarely encountered by pathologists and has rarely been reported in literature. This review aimed to examine the clinicopathological features, immunohistochemistry, treatment, and outcomes of gallbladder angiosarcoma.

METHODS

A search of the PubMed, Science Direct and Google Scholar was done with the search terms ("angiosarcoma" OR "angiosarcomas") AND ("gallbladder" OR "gallbladders"). Based on inclusion and exclusion criteria, only case reports could be used for this review.

RESULT

8 case reports were chosen in the end for analysis. The mean age of the patients at presentation was 65 years. It was most frequently observed in males. Abdominal pain and palpable mass were the most commonly reported symptoms. Cholelithiasis and anemia were also reported. On histopathology morphologically epithelioid appearance of angiosarcoma was evident. Cytokeratin (CK) AE1/AE3, Von willebrand factor, Factor VIII antigen, Vimentin, CD31 were positive. Meanwhile, UEA, CD34, CD117, S-100, Keratin, EMA, and CEA showed negative outcome. Surgery was the preferred method of treatment and a mean 10-months follow-up was done.

CONCLUSION

Despite the unavailability of convincing data, histological and immunohistochemical analyses play a major role in the diagnosis of gallbladder angiosarcoma. Nevertheless, more comprehensive clinical studies are required to provide universal guidelines for the treatment and diagnosis of angiosarcoma of the gallbladder.

Angiosarcoma arising in a schwannoma of the peripheral nervous system: illustrative case

BACKGROUND

Schwannomas of the peripheral nerves are benign tumors that can very rarely undergo malignant transformation. These lesions are particularly challenging to diagnose via noninvasive techniques but can have significant implications for treatment.

OBSERVATIONS

This is a case of a 70-year-old female with a prior history of a right sciatic notch tumor that was diagnosed as a conventional schwannoma via histology from an initial biopsy and subsequent surgical debulking. Unfortunately, she experienced significant worsening of her motor deficit, whereby her postoperative foot weakness progressed to complete foot drop in less than 2 years. In addition, she demonstrated significant radiological progression, with more than 1 to 2 cm of growth in each dimension at her subsequent evaluation, along with intractable right leg pain. An additional operation was performed to completely remove the 7 × 8 cm tumor, and histology demonstrated angiosarcoma within a schwannoma. There was no evidence of recurrence at 15 months, and the patient had significant improvement in her pain.

LESSONS

Rapidly worsening function and radiological progression are not typically seen with conventional benign nerve sheath tumors and should prompt consideration of other lesions. Angiosarcoma within schwannoma is a rare pathology and optimal therapies for these tumors in terms of surgical timing and adjuvant therapy are still unknown.

Updates in Pathology for Retroperitoneal Soft Tissue Sarcoma

Retroperitoneal tumors are extremely rare. More than 70% of primary retroperitoneal soft tissue tumors are malignant. The most common sarcomas in the retroperitoneum include liposarcomas and leiomyosarcoma, however other sarcomas, along with benign mesenchymal tumors, can occur. Sarcomas are a heterogenous group of tumors with overlapping microscopic features, posing a diagnostic challenge for the pathologist. Correct tumor classification has become important for prognostication and the evolving targeted therapies for sarcoma subtypes. In this review, the pathology of retroperitoneal soft tissue sarcomas is discussed, which is important to the surgical oncologist. In addition, less common sarcomas and benign mesenchymal tumors of the retroperitoneum, which may mimic sarcoma clinically and pathologically, are also discussed.

Practical Approach to Histological Diagnosis of Peripheral Nerve Sheath Tumors: An Update

Peripheral nerve sheath tumors encompass a wide spectrum of lesions with different biological behavior, including both benign and malignant neoplasms as well as the recent diagnostic category, i.e., “atypical neurofibromatous neoplasm with uncertain biologic potential” to be used only for NF1 patients. Neurofibromas and schwannomas are benign Schwann-cell-derived peripheral nerve sheath tumors arising as isolated lesions or within the context of classical neurofibromatosis or schwannomatoses. Multiple tumors are a hallmark of neurofibromatosis type 1(NF1) and related forms, NF2-related-schwannomatosis (formerly NF2) or SMARCB1/LZTR1-related schwannomatoses. Perineuriomas are benign, mostly sporadic, peripheral nerve sheath tumors that show morphological, immunohistochemical, and ultrastructural features reminiscent of perineurial differentiation. Hybrid tumors exist, with the most common lesions represented by a variable mixture of neurofibromas, schwannomas, and perineuriomas. Conversely, malignant peripheral nerve sheath tumors are soft tissue sarcomas that may arise from a peripheral nerve or a pre-existing neurofibroma, and in about 50% of cases, these tumors are associated with NF1. The present review emphasizes the main clinicopathologic features of each pathological entity, focusing on the diagnostic clues and unusual morphological variants.

Breast Shwannoma - Time to explore alternative management strategy?

Schwannoma (SCH) is a benign peripheral nerve sheath neoplasm of Schwann cell origin. It can be observed anywhere whilst the breast is uncommon site. Preliminary investigations are not entirely diagnostic and surgical excision is often required to reach a conclusion. We conducted a retrospective review in two European Breast units to know more about this rare condition. Herein, we provide a comprehensive review and we question whether the surgical approach to management can be changed.

Posterior Mediastinal Epithelioid Angiosarcoma Arising in Schwannoma: A Case Report and Review of the Literature

Epithelioid angiosarcoma arising in schwannoma is an extremely rare mesenchymal tumor that accounts for only 1 to 2% of all sarcomas. This type of tumor occurs in all parts of the body, most often in the skin and soft tissues and rarely in the mediastinum. The present study describes the case of an asymptomatic, 58-year-old male who presented with epithelioid angiosarcoma in the posterior mediastinum during a physical examination. Enhanced computed tomography of the chest revealed a 3.5 × 3.1-cm mass in the posterior mediastinum. Thoracoscopic mediastinal mass resection was performed under general anesthesia due to the possibility that the tumor was malignant. Pathological examination revealed the presence of angiosarcoma and schwannoma components. Immunohistochemical staining for cluster of differentiation (CD) 31, CD34, early growth response (EGR), vimentin, Sry-related HMG box (SOX)-10 and S-100 was strongly positive. The patient recovered and was discharged on postoperative day 5. Two months postsurgery, the patient returned for evaluation, and no evidence of tumor recurrence was observed.

Epithelioid Sarcoma of the Peripheral Nerve: Clinicopathologic Series of Three Cases and Literature Review

OBJECTIVES

Epithelioid sarcoma (ES) rarely arises in the nerve. To increase our understanding of this unusual tumor originating in the nerve, we describe the features of three cases and review the literature.

METHODS

Clinical data, imaging, pathology, treatment, and follow-up are detailed. A systematic literature review was conducted.

RESULTS

Two patients were male and one female; the median age was 24 years. The patients had neurologic symptoms, and the tumors arose in large nerves and ranged from 2.4 to 5.8 cm. The tumors were avid on positron emission tomography-computed tomography and showed increased signal intensity on T2-weighted magnetic resonance imaging. Centered in the nerve, the tumors grew with an infiltrative pattern and encased the nerve fascicles. All were treated with wide resection, and adjuvant treatment included combinations of chemotherapy and radiation. One recurred, and the limb was amputated. Metastases were documented to lymph nodes, lung, pleura, and skin. One patient died of disease after 54 months. Literature review including our cases showed that tumors stained with pancytokeratin (9/9), EMA (4/4), and CD34 (7/7); there was loss of INI1 in all six cases tested.

CONCLUSIONS

ES rarely arises in the peripheral nerve, and its infiltrative nature often requires morbid surgery. The differential includes a variety of benign and malignant epithelioid neoplasms.

What's new in nerve sheath tumors

Peripheral nerve sheath tumors are commonly encountered and frequently pose challenges to the pathologist and the clinician. This review discusses the wide range of entities with an emphasis on new discoveries in the past decade. Clinical, histologic, immunohistochemical, and pathogenetic findings are discussed with an emphasis on clinical implications and differential diagnosis.

Mediastinal epithelioid angiosarcoma arising in schwannoma: The first case in the literature

Angiosarcoma arising in a long-standing schwannoma is extremely rare and only a few cases were reported in the English literature. Besides tumors arising from vagus, sciatic or adrenal nerves, tumors growing on neck, foot or kidney were also described. To the best of our knowledge, in this article, we report the first mediastinal case occurring in longstanding schwannoma in a 53-year-old female patient. The patient was admitted to our clinic with severe dyspnea and palpitation. Her medical history showed a progressive right-sided paramediastinal mass which was first diagnosed in 2002. Three transthoracic needle biopsies performed in 2002, 2015 and 2016 were all non-diagnostic. An operation was suggested since 2002, but the patient has not accepted. Thorax computed tomography and magnetic resonance imaging revealed a huge mediastinal mass nearly fulfilling the right hemithorax. A diagnosis of "malign spindle cell tumor" was established with the last transthoracic biopsy and total surgical resection via posterolateral throcatomy was performed. Microscopically, tumor was composed of two components: a benign schwannoma and an epithelioid angiosarcoma. Endothelial and neural cell differentiations were confirmed immunohistochemically.

Intrathoracic Malignant Peripheral Nerve Sheath Tumor with Angiosarcoma in a Child with NF1

Malignant peripheral nerve sheath tumors (MPNSTs) are uncommon in children and adolescents but occur more frequently in NF1 patients. Angiosarcomatous differentiation in MPNSTs is a rare entity with poor prognosis. We report on a 13-year-old boy with intrathoracic angiosarcoma arising in MPNST associated with NF1.

Metastatic angiosarcoma arising in malignant peripheral nerve sheath tumor in a young patient with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is a cancer predisposition syndrome with an incidence of approximately one in 3,000 and a lifetime risk of malignancy estimated at 8-13%. Here, we report the case of a patient with NF1 who developed synchronous malignant peripheral nerve sheath tumors, one with a focus of angiosarcoma. He succumbed to metastatic angiosarcoma despite local resection and adjuvant chemotherapy. This case highlights the need for monitoring for malignancy in NF1 patients, the risks of sampling error during tumor biopsy, and the clinical decision - making involved in choosing a therapeutic plan for a patient with multiple simultaneous malignancies.

Malignant Peripheral Nerve Sheath Tumor of the Inguinum and Angiosarcoma of the Scalp in a Child with Neurofibromatosis Type 1

Benign and malignant tumors are common in the setting of neurofibromatosis type 1 (NF1). Malignant peripheral nerve sheath tumor (MPNST) and angiosarcoma are rare tumors in children and adolescents and mostly occur in young patients in relation to NF1. Both histological types can be present in the same tumor mass in patients with NF1. We present a case of 12.5-year-old girl with NF1 who first presented with MPNST of the right inguinal region and 1.5 years later with unrelated angiosarcoma of the scalp.

Synovial Sarcoma of Peripheral Nerves: Analysis of 15 Cases

Synovial sarcoma of peripheral nerve (SSPN) is rare with only 26 cases reported in English. SSPN is often mistaken for a benign or malignant peripheral nerve sheath tumor (PNST) by clinicians and pathologists. Fifteen cases of SSPN were retrieved from the pathology files of 3 institutions. All tumors arose in a nerve based on imaging and/or operative findings and the diagnoses were histologically confirmed. Neuropathic symptoms predominated in 11 women and 4 men, 19- to 62-year-old (median, 39 years) with tumors involving the ulnar (5), median (3), peroneal (3) or sciatic (2) nerve, or the L4 or T1 nerve root (2). Tumor sizes ranged from 2 to 13 cm (median, 3.8 cm). The leading clinical diagnosis was PNST (9). Treatment was surgical (14) supplemented with radiation therapy (8) and chemotherapy (6). Fourteen tumors were monophasic and 1 was biphasic; 4 had poorly differentiated (PD) foci (1 rhabdoid). Diagnoses in 12 cases were verified by fluorescence in situ hybridization, reverse transcription polymerase chain reaction or both methods. Follow-up in 14 patients (median, 32 mo) revealed that 2/4 patients with PD tumors died with pulmonary metastases; another was alive with no current evidence of disease (NED) following 2 local recurrences, while the fourth had NED. In contrast, 9/10 patients without PD tumors were alive (7 NED) and 1 died at 12 months with pulmonary infiltrates. SSPN is under-recognized clinically and histologically as it mimics benign and malignant PNST. Molecular analysis is recommended to confirm the diagnosis. PD foci, including rhabdoid areas, may portend a worse outcome, similar to non-neural-based tumors.

Malignant Transformation of Vagal Nerve Schwannoma in to Angiosarcoma: A Rare Event

Schwannomas are benign, rare peripheral nerve sheath tumors that occur in the head and neck region. Some physicians opt to closely observe cases of schwannoma of the neck on an outpatient basis rather than to perform radical surgery. However, there is a possibility, albeit rare, of malignant transformation of a benign schwannoma. Here, we are reporting the first case from the Indian subcontinent which was transformed into the angiosarcoma from benign vagal schwannoma over a long period. A 47-year-old male patient complaining of left sided neck swelling since last 12 years, swelling was insidious in onset, gradually progressive very slowly. In last 2 months, the size of the swelling was suddenly increased. On examination, there was an approximately 6 cm × 6 cm of size, firm, nodular, well-defined, nontender swelling in the left lateral part of the neck. Fine-needle aspiration cytology (FNAC) revealed paraganglioma and magnetic resonance imaging demonstrated very clearly a tumor, its morphology, and its relation to the surrounding structures, the tumor was thought to be a vagal schwannoma. Surgery was done, and the whole of the tumor was removed in toto. On final histopathological diagnosis, the tumor was proved to be angiosarcoma developed from vagal schwannoma. Postoperative chemotherapy was given but due to distant metastasis, the patient died. Long standing neck masses can convert into malignancy as in our case, therefore, work up of the patient should be done properly. Multiple FNAC should be done because single FNAC can give the false negative result as in our case. This was our diagnostic drawback not to do multiple computed tomography guided FNAC.

Malignant Peripheral Nerve Sheath Tumor With Osseous Heterologous Differentiation in Uncommon Locations (Heart and Retropharynx)

We report two cases of malignant peripheral nerve sheath tumor (MPNST) in an uncommon location (heart and retropharynx) both with divergent osseous heterologous differentiation. We present the pathological and immunohistochemical studies that confirmed the neurogenic origin. The histopathology of the tumor arising in the retropharynx showed a transition from a neurofibroma to MPNST, making this a new report of an MPNST arising from a plexiform neurofibroma without neurofibromatosis. Primary cardiac MPNST with osseous differentiation has never been reported before. In conclusion, the histology of MPNSTs is very heterogeneous, showing no specific diagnostic immunoprofile or genetic alteration. Thus, it is important to rule out other histologically similar tumors, particularly in cases arising in uncommon locations or tumors with divergent heterologous differentiation.

Epithelioid angiosarcoma arising in schwannoma of the kidney: report of the first case and review of the literature

Background

Schwannoma and angiosarcoma are infrequent pathologies that have been rarely reported in the kidney. Angiosarcoma is an uncommon malignant tumor presenting a recognizable vascular differentiation. It can develop in any site but the most common locations include the skin, soft tissues, breast, bone, liver, and spleen while renal localization has been very rarely reported in the literature. Schwannoma is a benign peripheral nerve sheath tumor composed of cells with the immunophenotype and ultrastructural features of differentiated Schwann cells. It has a wide anatomical distribution but the most frequent locations include subcutaneous tissues of the extremities and the head and neck region and the retroperitoneal and mediastinal soft tissues. The occurrence of an angiosarcoma in a pre-existing schwannoma is an extremely rare event with <20 cases reported in worldwide literature. In the present study, a renal case of angiosarcoma arising in schwannoma is presented with a detailed review of the pertinent literature.

Case Presentation

A 56-year-old man was admitted with a few days history of lower back pain and hematuria. Abdominal ultrasound showed a mass inside the left renal medulla. Subsequent imaging investigations with computed tomography and magnetic resonance confirmed the presence of the lesion and showed a pulmonary metastasis.

Conclusions

The final histopathological examination led to the diagnosis of epithelioid angiosarcoma arising in a schwannoma. The patient came to death a few months later due to a massive hemothorax. To the best of our knowledge, the present is the first case of an angiosarcoma arising in a schwannoma of the kidney.

Angiosarcoma Developing in a Vagal Schwannoma: A Rare Case Report

Angiosarcoma arising in a schwannoma is extremely rare with only fourteen cases having been reported in the literature to the best of our knowledge. Amongst these fourteen, only five cases developed from vagal schwannoma. We describe a case of epithelioid angiosarcoma arising in a long standing vagal schwannoma in a 41 years male patient. Grossly the tumor was well encapsulated with variegated cut surface. On microscopy the tumor had two distinct components composed of benign schwannoma and malignant angiosarcoma which were further confirmed by immunohistochemistry. On further work up, he was found to have multiple distant metastases. This is the sixth reported case of angiosarcoma arising in a vagal schwannoma. The proposed histogenesis of this rare transformation, its prognostic factors and a review of literature regarding this entity is discussed.

Epithelioid angiosarcoma arising in an adrenal cortical adenoma: a case report and review of the literature

Adrenal masses are common incidental imaging findings, with the majority comprising benign adrenal cortical adenomas. However, the differential diagnosis is extensive and includes both primary and secondary malignant lesions. Primary adrenal angiosarcomas are rare and often exhibit epithelioid morphology, which can present a diagnostic pitfall. We report an exceptional "incidentaloma" in a 60-year-old lady, which showed the features of a primary epithelioid angiosarcoma arising within an adrenal cortical adenoma. No other primary tumor was identified on extensive imaging. This unusual combined tumor has been reported only once before, to the best of our knowledge. The pattern of infiltration of the malignant endothelial cells raises the suggestion that the angiosarcoma arose from vascular elements of the adenoma.

Case of malignant transformation of vagus nerve schwannoma to angiosarcoma

BACKGROUND

It is known that benign tumors have the potential for malignant transformation. Malignant transformation of vagus nerve schwannoma to angiosarcoma is very rare.

METHODS

We report a case of malignant transformation in which the initial diagnosis was subsequently altered to angiosarcoma originating from the vagus nerve. We compared the findings of MRI and fine-needle aspiration (FNA) at initial diagnosis with those after malignant transformation.

RESULTS

MRI revealed that the mass property had been changed from the initial tumor; also the FNA findings were significantly different from those in the previous ones. The patient had significant clinical progression with multiple cranial neuropathies and died.

CONCLUSION

Schwannomas sometimes undergo malignant transformation; therefore, surgery should be recommended. If follow-up observation is chosen, MRI and FNA should be regular and patients should sign a statement acknowledging awareness of the potential for malignant transformation.

Vascular sarcomas

Vascular sarcomas are soft-tissue tumors that arise from the endothelium with a malignant potential. This review discusses the management of epithelioid hemangioendothelioma (EHE) and angiosarcoma. EHE is a vascular tumor of intermediate malignant potential with an indolent course. EHE arising from the liver, lung, or bone tends to be multifocal and the rate of progression is slow and often unpredictable. Treatment should be considered in patients with significant symptomatic deterioration and/or progressive disease on imaging studies. Various cytotoxic and targeted therapies are available for management, with disease stabilization as the most common outcome. Angiosarcoma is an aggressive vascular tumor with a high malignant potential. Multidisciplinary care is critical for the management of localized disease, and the best outcomes are often observed in patients when a combination of systemic and local therapy options is used. Metastatic angiosarcoma is treated primarily with systemic therapy, and several cytotoxic and targeted therapies are available, alone or in combination. The choice of therapy depends on several factors, such as cutaneous location of the tumor, performance status of the patient, toxicity of the treatment, and patient goals.

Neurogenic tumors of soft tissue

Neurogenic tumors are an uncommon yet important category of soft tissue tumors in children and adolescents because of their frequent association with various genetic syndromes. The heterogeneous cellular composition of the peripheral nerve and the wide metaplastic capacity of the neural crest and its derivatives generate a variety of neoplasms with neurogenic differentiation. This article reviews the clinicopathologic features and differential diagnosis of neurogenic tumors in the first two decades of life, and highlights use of selected ancillary methods for diagnosis.

Angiosarcoma with malignant peripheral nerve sheath tumour developing in a patient with klippel-trénaunay-weber syndrome

Purpose: We discuss the coexistence of Klippel–Trénaunay–Weber syndrome with various malignancies, the possible histogenetic pathways and therapeutic implications.

Patient: We report on a 46-year-old man presenting with increasing pain and swelling of his right lower leg after fracturing his fibula. Since birth he was known as having the uncommon syndrome of Klippel–Trénaunay–Weber of his right lower leg.

Methods: Our patient underwent an above-knee amputation for biopsy-proven malignant vascular tumour, first thought to be a composite hemangio-endothelioma and/or angiosarcoma with lung metastases.

Results: In the amputated extremity, a vascular malformation was found with tumour showing various components with foci of angiosarcoma adjacent to diffuse neurofibroma and areas with high-grade malignant peripheral nerve sheath tumour. Amputation and palliative chemotherapy were indicated, but he died of pulmonary and cerebral metastases 2 months postoperatively.

Discussion: This case describes an angiosarcoma with malignant peripheral nerve sheath tumour developing in a patient with Klippel–Trénaunay–Weber syndrome. A case never described before in literature and probably, as in our case, difficult to diagnose at first biopsy.

Malignant peripheral nerve sheath tumors of cranial nerves and intracranial contents: a clinicopathologic study of 17 cases

Malignant peripheral nerve sheath tumors (MPNSTs) arising from cranial nerves or their branches are very uncommon. The literature consists mainly of isolated case reports and small series. We identified 17 such cases in 14 males and 3 females. With one exception, the tumors affected adults (age range 5 to 69 y, mean 39, median 32). Sites of involvement included vestibular nerves (n=6), vagal nerves (n=4), facial nerves (n=3) (1 centered in the geniculate ganglion), and 2 unspecified cranial nerves in the posterior fossa. In addition, 1 tumor involved the optic chiasm (n=1). Only 1 tumor arose in brain parenchyma of (frontal lobe). All but 3 lesions were intracranial. Five tumors arose in patients who satisfied clinical criteria for neurofibromatosis type 1 (NF1). One patient with a vestibular tumor and presumed NF2 had previously undergone resection of a contralateral vestibular cellular schwannoma. One posterior fossa tumor was a malignant melanotic schwannoma. Four patients had postirradiation malignant peripheral nerve sheath tumors, 2 having been treated for optic chiasm glioma, both being NF1 affected. One patient was irradiated for hypothalamic pilocytic astrocytoma and another for cervical Hodgkin disease. Identifiable precursor lesions included schwannoma (n=4), plexiform neurofibroma (n=2), and solitary intraneural neurofibroma (n=2). All tumors were histologically high grade (6 grade III and 10 grade IV). Three tumors showed heterologous elements, 2 osseous, and 1 rhabdomyoblastic. More often scattered than diffuse, S-100 protein staining was noted in 11 of 16 tumors and variable collagen IV staining in 10 of the 16. Immunoreactivity for p53 protein was diffuse and strong in 7 of 11 tumors. Twelve patients died within 17 months to 3 years of diagnosis, 1 was lost to follow-up, 2 are very recent cases, and 2 patients are currently alive, 1 after 2 recurrences, and another with spinal leptomeningeal metastases. Malignant cranial nerve sheath tumors are rare and are associated with the same poor prognosis as those of spinal nerves at other sites.

A case of fibroblastic low-grade malignant peripheral nerve sheath tumor--a true neurofibrosarcoma

The authors report a case of low-grade retroperitoneal malignant peripheral nerve sheath tumor (MPNST) showing Schwannian and fibroblastic differentiation in individual tumor cells. The tumor was detected in a 29-year-old male and posed diagnostic difficulty because of the unusual morphologic and immunophenotypic features. Morphologic examination of the H&E sections revealed a rather circumscribed, highly vascular, moderately cellular spindle cell tumor. The neoplastic cells were arranged in vague, short fascicles, distributed haphazardly amid hemangiopericytoma-like vascular channels, and showed occasional whorls. Myxoid stroma and keloid-like collagen bundles were frequently seen. There were satellite nodules outside the main tumor mass and low mitotic activity but no necrosis. The tumor cells stained strongly and diffusely for both S-100 protein and CD34. Electron microscopy revealed cells with processes and focal lamina, and prominent rough endoplasmic reticulum. Although the capacity of MPNST to exhibit divergent differentiation is well known, fibroblastic differentiation is generally poorly and inconsistently documented. The present case represents an unambiguous demonstration of the co-expression within individual tumor cells of Schwannian and fibroblastic differentiation in a low-grade MPNST. The literature on this subject is reviewed.

The controversial nosology of benign nerve sheath tumors: neurofilament protein staining demonstrates intratumoral axons in many sporadic schwannomas

Schwannomas are benign peripheral nerve sheath tumors believed to be composed purely of cells with ultrastructural features of Schwann cells; these tumors are believed to develop eccentrically from the surface of nerves and not to contain axons, other than immediately beneath the capsule. This concept has recently been disputed in cases associated with neurofibromatosis type 2. The usual presence of intratumoral axons in neurofibromas is said to allow easy distinction from schwannomas. Eighty sporadic schwannomas (20 conventional, 20 cellular, 20 ancient, 10 gastric, and 10 plexiform) were retrieved from the authors' files. Hematoxylin-and-eosin stained slides were reviewed, diagnoses were confirmed and all tumors were stained for S-100 protein and neurofilament protein (NFP). The amount (rare, focal, multifocal, and diffuse) and distribution (central and/or peripheral) of axons within the tumors were analyzed. All tumors were strongly and diffusely positive for S-100 protein (nuclear and cytoplasmic staining). NFP-positive axons were identified in 11 of 20 (55%) conventional schwannomas (2 rare, 4 focal, 3 multifocal, and 2 diffuse; 5 central, 4 peripheral, and 2 central and peripheral) and in 15 of 20 (75%) cellular schwannomas (3 rare, 6 focal, and 6 multifocal; 12 central, 1 peripheral, and 2 central and peripheral). Of the 20 ancient schwannomas, 7 cases (35%) showed intratumoral axons, highlighted by NFP immunostaining (1 rare, 4 focal, 1 multifocal, and 1 diffuse; 4 peripheral, 2 central, and 1 central and peripheral). Most cases of gastric schwannoma showed no evidence of intratumoral axons; 9 cases (90%) were negative for NFP and only 1 case (10%) was positive (focal and central). Seven of 10 cases (70%) of plexiform schwannomas were negative for NFP, whereas only 3 cases (30%) showed positive axons (2 multifocal and 1 focal; 3 central). The unexpected but quite frequent presence of intratumoral axons in schwannomas argues against conventional views of these lesions' pathogenesis as an eccentric encapsulated lesion and raises the possibility that a more diverse cell population, perhaps more closely resembling neurofibromas, may constitute these neoplasms. Although NFP-positive axons were most often present in the conventional and cellular variants of schwannoma, their presence was also observed in a minority of ancient, gastric and plexiform schwannomas. Differentiation between neurofibroma and schwannoma in cases with overlapping cytoarchitectural features should not be based solely on the presence or absence of NFP-positive axons within a given tumor.

Primary Epithelioid Angiosarcoma of the Male Breast: Report of a Case

We report a case of primary epithelioid angiosarcoma of the male breast. The patient was a 20-year-old Chinese man who presented with a huge tumor just below the left nipple. Histopathological examination and immunohistochemical analysis confirmed a diagnosis of primary epithelioid angiosarcoma of the male breast, without axillary lymph node metastasis. We review the relevant literature on this rare malignant tumor.

Epithelioid angiosarcoma arising in a deep-seated plexiform schwannoma: a case report and literature review

Angiosarcoma developing within a schwannoma is rare, and only 8 cases have been reported in the literature. Its association with a plexiform schwannoma has never been reported. We describe an epithelioid angiosarcoma arising in a plexiform schwannoma of the sciatic nerve in a 73-year-old man not known to have von Recklinghausen disease. Grossly, the tumor forms a long tubular mass with a multinodular growth pattern on the cut surface. Microscopically, these nodules display characteristics of a schwannoma, including Antoni A, Antoni B, and Verocay bodies. Adjacent to these nodules are high-grade anaplastic epithelioid cells growing in solid sheets, cords, and nests with focal vasoformative channels. The anaplastic cells are immunoreactive to CD31, CD34, and factor VIII related antigen, supporting their endothelial differentiation. Local recurrence and multiple pulmonary metastasis occurred 3 months after complete excision of the tumor. This case demonstrates the first occurrence of an epithelioid angiosarcoma in a deep-seated plexiform schwannoma with an aggressive clinical behavior.

Divergent differentiation in malignant soft tissue neoplasms: the paradigm of liposarcoma and malignant peripheral nerve sheath tumor

In tumors clonality does not always translate into morphologic uniformity. While most sarcomas exhibit only one line of histologic differentiation, a minority may display a strikingly diverse phenotype in addition to the main lineage. This phenomenon not only presents a diagnostic problem but also raises questions about the commitment of tumor cells toward a specific phenotype. Among sarcomas, malignant peripheral nerve sheath tumor (MPNST) and dedifferentiated liposarcoma are two entities in which divergent differentiation is a relatively frequent event. Diagnostically it is crucial to recognize the "primary" sarcoma in such tumors correctly and distinguish it from the "secondary" divergent elements. The presence of the latter could be the first morphologic clue to a specific sarcoma type. Even though it may be difficult to explain the pathogenesis of divergent differentiation, divergence still illustrates that the phenotype of a tumor cell is not set in stone but can be modulated or switched by a number of factors.

Differential diagnosis of non-epithelial tumors of the pancreas: malignant non-epithelial pancreatic tumor with focal pigmentation

Non-epithelial tumors only rarely affect the pancreas. In this report, we describe a malignant non-epithelial tumor with combined characteristics of malignant peripheral nerve sheath tumor (MPNST) and malignant melanoma. To more closely define the differential diagnosis of MPNST with focal pigmentation versus metastatic melanoma resembling MPNST, the tumor was investigated using histomorphology, immunohistochemistry, electron microscopy, and comparative genomic hybridization. As a result, from these analyses and from clinical findings, the diagnosis of a pancreatic MPNST with focal pigmentation was favored. However, the diagnosis of a malignant melanoma or a composite tumor could not be definitely ruled out, due to the considerable morphological and genotypical overlap between both entities, which can be explained by the close histogenetic relationship between both tumor entities.

Intraneural synovial sarcoma: two cases

We report two cases of intraneural synovial sarcoma. The first patient is a 46-year-old female who presented for several months with soft-tissue mass in the right infra-auricular region. The second patient is a 11-year-old girl who fell and then presented with pain in the area innervated by the right C7 spinal root and a nodule identified in the nerve root foramina. Both lesions were of small size and presented with features of synovial sarcoma. A biphasic variant was found in case 1 and a monophasic variant was present in case 2. Immunohistochemical studies were performed to confirm the diagnosis, excluding the main differential diagnoses, namely schwannoma and malignant peripheral nerve sheath tumor. Ultrastructural study was performed in case 2 allowing exclusion of other possible diagnoses. Molecular studies were performed on paraffin-embedded tissue in both cases and revealed the known characteristic t(X;18)(SYT-SSX) translocation.

Neuroblastoma-like schwannoma: a case report and review of the literature

We report a case of schwannoma (neurilemmoma) predominantly composed of small cells arranged in rosettes around central collagenous cores and discuss the differential diagnosis of this unusual variant. Schwannoma with giant rosettes, previously designated as neuroblastoma-like schwannoma by Goldblum et al., must be differentiated from neuroblastoma, peripheral neuroectodermal tumors, and malignant change in a schwannoma.

Malignant schwannoma of the sciatic nerve originating in a spinal plexiform neurofibroma associated with neurofibromatosis type 1--case report

A 26-year-old man with neurofibromatosis type 1 (NF1) presented with a giant malignant schwannoma of the sciatic nerve. The differential diagnosis of malignant peripheral nerve sheath tumor (MPNST) was based on clinical, radiological, and histological evidence. The tumor apparently originated in a spinal plexiform neurofibroma. The lesion was resected totally without neural damage to the sciatic nerve. However, the tumor recurred within 2 months. The patient died of unknown factors probably associated with the spinal involvement. MPNST associated with NF1 has a poor prognosis due to recurrence or metastasis despite complete macroscopic removal.

Cardiac epithelioid angiosarcoma presenting as cutaneous metastases

BACKGROUND

Cardiac angiosarcoma is a rare tumor that has a predilection for middle-aged males and a marked predominance in the right atrium. The tumor may present abruptly with a fulminant clinical course. Initial presentation with metastatic disease is rare. Only one case has been reported of a patient who presented with cutaneous metastases.

METHODS AND RESULTS

We here report the case of a 51-year-old man who initially presented with cutaneous metastases in the absence of cardiac symptoms. The skin biopsy was diagnosed as metastatic undifferentiated sarcoma. The patient died 26 days later with widely disseminated disease. At autopsy a tumor arising in the wall of the left atrium and in the interatrial septum was found. After an immunohistochemical study including CD31 and CD34 stains the diagnosis of cardiac pure epithelioid angiosarcoma was made. To the best of our knowledge this tumor variant has not been documented in the heart until now.

CONCLUSION

Although cardiac angiosarcoma is a rare neoplasm, its presence should be suspected in patients with cutaneous metastatic angiosarcoma without an evident source of the tumor, even in absence of cardiac symptoms.

Expanding the spectrum of malignant change in schwannomas: epithelioid malignant change, epithelioid malignant peripheral nerve sheath tumor, and epithelioid angiosarcoma: a study of 17 cases

Schwannomas (neurilemmomas) rarely undergo malignant change, most often in the form of either malignant peripheral nerve sheath tumor (MPNST) or angiosarcoma. We characterize the clinical features and the histopathologic spectrum of 17 schwannomas with evidence of malignant change. The study group comprised 7 males and 10 females with an age range of 16 to 76 years, (median, 40 yrs). None of the patients had neurofibromatosis. Lesions ranged in size from 0.6 to 10.5 cm (median, 4.0 cm) and arose mainly in the limbs/limb girdles (7 cases) or head and neck region (7 cases). All tumors contained areas of conventional benign schwannoma. Four cases of pure epithelioid malignant peripheral nerve sheath tumor (EMPNST) were identified, three of which showed immunopositivity for S-100 protein. Four angiosarcomas were identified, predominantly epithelioid-type. Ten schwannomas had an appearance that we have designated epithelioid malignant change (EMC) and, in one of these, EMC coexisted with EMPNST. Large epithelioid cells with abundant eosinophilic cytoplasm, vesicular chromatin, and prominent nucleoli (morphologically similar to cells of EMPNST) were distributed throughout the schwannoma--singly, in clusters, and in one case a microscopic nodule of such cells was also present. These large epithelioid cells were strongly positive for S-100 protein. Although follow-up data so far are limited, 1 of 5 patients with EMC in whom meaningful follow up was available developed repeated local recurrence (median follow up, 21 mos), one patient each with EMPNST and angiosarcoma died of local and metastatic disease. Pure EMPNST is rare; however, we confirm the tendency of MPNST to show epithelioid cytomorphology when arising in a benign schwannoma. We also confirm the distinctive (albeit infrequent) tendency of angiosarcoma to arise in schwannomas. We describe EMC in schwannomas and suggest that this represents a putative precursor lesion of EMPNST. At this time, we do not have an explanation for the tendency of schwannomas to show epithelioid cytomorphology when they undergo malignant change.