Hemangiopericytoma: a light microscopic and ultrastructural study

Glomangiopericytoma of the inferior nasal turbinate: A case report

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Glomangiopericytomas, which arises in the nasal cavity and may extend into the paranasal sinuses, is categorized as a borderline low malignancy tumor by the WHO classification.

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Complete transnasal endoscopic excision is the optimal treatment.

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A regular postoperative follow-up is recommended for early finding of tumor recurrence.

Introduction

Glomangiopericytoma is defined as a sinonasal tumor with perivascular myoid phenotype, which was first described in 1942 by Stout and Murray as a soft tissue tumor with characteristic proliferation including branching vessels and small vessel perivascular hyalinization.

The tumor accounts for less than 0.5 % of all sinonasal neoplasms. The World Health Organization (WHO) classified this tumor as glomangiopericytoma in 2005.

Case report

A 47-year-women presented with two years history of permanent left nasal obstruction and frequent epistaxis. Rhinoscopy revealed a friable grayish pink polypoidal mass, fully occupying the left anterior naris. Computed tomography showed a lesion involving the left nasal cavity, with a soft tissue density (70 UH) measuring 50 × 16 mm, widely infiltrative.

Endoscopic surgery was performed to remove the mass, considering the size, limited expansion and the accessible location of the tumor. The immunohistochemistry examination showed positive staining b-catenin tumor cells which confirmed the diagnostic of glomangiopericytoma.

After a 2 years follow-up, the patient showed no signs of recurrence.

Conclusion

Glomangiopericytomas generally arises in the nasal cavity and may extend into the paranasal sinuses. It is categorized as a borderline low malignancy tumor by the WHO classification. Complete transnasal endoscopic excision is the optimal treatment.

Intracranial Meningeal Hemangiopericytomas: An Analysis of Factors Affecting Outcome in 39 Cases Managed with Multimodality Treatment

Aim

To retrospectively evaluate the outcome of patients with intracranial meningeal hemangiopericytomas (MHPCs) and to analyze various factors for recurrence and survival in these patients.

Materials and Methods

We retrospectively reviewed the clinical data of 39 patients undergoing microsurgical resection for MHPCs at our institute from 2009 to 2015.

Results

Gross total excision (GTE) was achieved in 27 (69.2%) patients, whereas 12 (30.8%) underwent subtotal excision (STE). A total of 25 patients received radiotherapy (RT) (Conventional RT-15; GKT-10), 21 patients had a low grade tumor, while 18 had an anaplastic variant. Twenty patients (51.3%) developed recurrences and the average recurrence-free survival (RFS) was 56 months (range: 12-180 months). Eight patients (20.5%) died during the study period. The average overall survival (OS) was 77.2 months (range: 36-192 months). Two patients (5.1%) developed systemic metastases during follow-up. Patient age was not found to affect RFS or OS. GTE was associated with prolonged RFS and OS but the impact was not statistically significant (P-values = 0.160 and 0.414, respectively). Low tumor grade was associated with statistically significant longer RFS as well as OS (P-values = 0.049 and 0.013, respectively). Addition of adjuvant RT was associated with statistically significant prolongation of RFS (P value = 0.016); however, it was not associated with statistically significant OS benefits (P-value = 0.758).

Conclusions

Our study suggests that a greater extent of excision, lower tumor grade, and addition of adjuvant RT have a positive impact on both RFS and OS; however, low grade and adjuvant RT were the only factors associated with statistically significant prolongation of RFS and only tumor grade was associated with statistically significant OS benefits.

Very rare localization of a retroperitoneal hemangiopericytoma revealed by lumbosciatalgia: A case report

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Hemangiopericytoma is a rare vascular tumor representing about 1% of all vascular tumors and approximatively 5% of all soft tissues sarcomas.

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Retroperitoneal hemangiopericytoma is a rare location.

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The radiologic feature suggests the diagnosis but the pathologic findings associated to immune histochemistery remain the only tool to confirm the diagnosis.

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Surgical excision is the most preferred treatment as it helps in relieving the symptoms as well as confirm the diagnosis.

Introduction: Hemangiopericytoma is a rare vascular tumor representing about 1% of all vascular tumors and approximatively 5% of all soft tissues sarcomas that arises from the pericytes of Zimmerman surrounding capillaries and postcapillaries vessels. Retroperitoneal hemangiopericytomas are rare among the localisations as it usually occurs in lower and upper extremities.

Presentation of case: We present a case of 31-year-old man with a well-defined retro peritoneal mass measuring about 105 × 73 × 83 mm at right lower quadrant of the abdomen anterior to right psoas muscle. Intraoperatively, an large mass measuring 10 × 8 cm was found arising from the retro peritoneum. A monobloc excision was performed. The postoperative course was uneventful. Histopathological examination with immune histochemistry revealed that tumoral cells were positive for desmin, CD34, smooth muscular antigen. Final diagnosis of hemangiopericytoma was made. On the last follow up at one year, he was symptom free.

Discussion: Hemangiopericytoma is a rare tumor. It takes origin from pericytes presenting as intervals along the walls of capillaries and post-capillary venules. Retroperitoneal hemangiopericytoma is a rare location. It is often discovered at late course, and can be revealed by various symptoms with the compression of the adjacent organs by the tumor Surgical resection should be considered in symptomatic cases or in case of diagnostic dilemma.

Conclusion: Retroperitoneal hemangiopericytoma can be benign but it should be treated the same way as aggressive tumors. It requires a careful and long term follow up.

Post-operative stereotactic radiotherapy for the treatment of intracranial haemangiopericytoma: 'A Study of Dose and Outcome'

INTRODUCTION

This study was performed to assess the relationship between tumour response and radiation dose in equivalent 2 Gy per fraction (EQD2).

METHOD

A retrospective cohort analysis of 21 patients with a diagnosis of intracranial haemangiopericytoma between 2000 and 2013 was included in this study. A total of 39 lesions were analysed. The equivalent dose in 2 Gy per fraction was calculated by assigning an alpha-beta ratio of 12 Gy. A paired t-test compared dose (EQD2) and tumour response, and as the outcome was binary, a logistic regression analysis was performed.

RESULTS

In total, there were 14 cases of progression and 25 cases of non-progression. It was estimated that for a one unit increase in EQD2, the odds of non-progression were increased by a factor of 1.13 (P = 0.026). After adjusting for PTV volume, the estimated effect of EQD2 (min) on tumour response was stronger, with an estimated odds ratio of 1.36 for an increase of one unit and an odds ratio of 21.6 for an increase of 10 units (P = 0.015). The dose range varied with varying PTV volumes. Based on the logistic model, the probability of having non-progression is larger than 50% for EQ2Dmin doses larger than 30-40 Gy, in particular for volumes larger than 3.67 cm3 .

CONCLUSION

This study demonstrates that there is a relationship between dose (EQD2) and outcome. With increasing dose, the likelihood of regression is higher. When adjusted for PTV volume, the response appeared stronger. The dose varied significantly with changes in the size of the PTV.

Hemangiopericytoma of the Nasal Cavity: A Review of 15 Cases over a 40-Year Period

Hemangiopericytomas are rare tumors of vascular origin most commonly found in the extremities or retroperitoneal area. When they originate from the nasal cavity and paranasal sinuses, they tend to be less aggressive and generally do not metastasize. The term “hemangiopericytoma-like lesion” has been coined for sinonasal hemangiopericytomas that display more benign histologic and growth characteristics than do those located elsewhere. Fifteen cases of hemangiopericytoma of the nasal cavity and paranasal sinuses were reviewed over the period 1951 to 1990; included are follow-up data on cases reported earlier from this institution. The clinical course, management, and outcome was evaluated and correlated with the histologic characteristics of the tumors. The recurrence rate in our series was 13.3%; the mean follow-up was 11 years. No patients died of their disease or had evidence of metastatic disease. This clinicopathologic review suggests that sinonasal hemangiopericytomas should not be classified as “hemangiopericytoma-like” lesions; rather, they should be expected to have significant local recurrence rates with low rates of distant metastasis and mortality. Long-term follow-up is essential as there can be local recurrence after many years.

Hemangiopericytoma of the Thyroid

A 52-year-old woman presented with a painless right thyroid mass of 4 months dura tion, with a recent increase in size in the last few weeks. The neoplasm was character ized by bland spindle cells with a low mitotic rate arranged around vascular elements of variable shape and caliber. Multiple immunohistochemical stains failed to show evi dence of epithelial, neuroendocrine, or specific mesenchymal differentiation. Electron microscopic studies revealed spindle cells with micropinocytotic vesicles, surrounded by variable but sometimes abundant basement lamina-like material. To the authors' knowledge, this is the first report of a typical hemangiopericytoma of the thyroid gland. This lesion must be distinguished from epithelial and neuroendocrine tumors with spindle cells and from other mesenchymal neoplasms that may occur in the thyroid. Int J Surg Pathol 2(4):311-318, 1995

Select Neoplasms of the Sinonasal Tract

The sinonasal tract (SNT) includes the nasal cavity and paranasal sinuses (maxillary, ethmoid, frontal, and sphenoid) and may give rise to a variety of nonneoplastic and neoplastic proliferations, including benign and malignant neoplasms. The benign neoplasms of the SNT include epithelial neoplasms of surface epithelial origin, minor salivary gland origin, and mesenchymal origin. The spectrum of malignant neoplasms of the SNT includes epithelial malignancies, sinonasal undifferentiated carcinoma, malignant salivary gland neoplasms, neuroectodermal neoplasms, neuroendocrine neoplasms, melanocytic neoplasm, and sarcomas. This article concentrates on some of the more common types of benign and malignant neoplasms.

Sinonasal hemangiopericytoma: case report and literature review

Hemangiopericytoma (HPC) is a rare vascular tumor that can arise in any organ system, but occurs most frequently in skeletal muscle. We present a case of a primary sphenoid sinus HPC unusual for its spontaneous remission after biopsy. There have been approximately 55 cases of sinonasal HPC reported in the literature, representing less than 5% of all lesions. In general, HPC behaves aggressively, demonstrating greater than 50% local recurrence and 10% metastatic disease. Although extended surgical resection is traditionally considered the most effective therapy for all HPC, critical literature review does not support this method of treatment for HPC occurring in the paranasal sinuses and skull base. Long-term follow-up indicates that the majority of sinonasal HPC have a benign clinical course regardless of treatment. As a result, we do not recommend extended resection as the initial therapy for sinonasal HPC. Instead, a period of observation coupled with serial MRI or CT scans should be used to detect tumor progression. These indolent tumors should undergo extended resection only after progression has been confirmed. In addition to the case report, a synopsis of the reviewed literature and a summary of treatment recommendations are also presented.

Sinonasal glomangiopericytoma: case report with emphasis on the differential diagnosis

Glomangiopericytoma (sinonasal-type hemangiopericytoma) is an uncommon sinonasal neoplasm with a perivascular myoid phenotype. This tumor differs from conventional soft tissue hemangiopericytoma in location, biologic behavior, and histologic features. The proposed cell of origin is a modified perivascular glomuslike myoid cell. Glomangiopericytoma is an indolent tumor that tends to arise in the sinonasal tract of older adults and has a low malignant potential with excellent prognosis after surgical resection. Histologically, this lesion is composed of a diffuse, subepithelial proliferation of bland, uniform, closely packed spindled cells growing in a variety of patterns. A distinctive vascular network composed of variably sized vascular channels, the smaller of which demonstrate perivascular hyalinization, is often present. We report the case of a 48-year-old woman with epistaxis and nasal obstruction who was diagnosed with glomangiopericytoma and discuss the histologic differential diagnosis.

Temporal fossa hemangiopericytoma: a case series

OBJECTIVE

Review clinical experience with temporal fossa hemangiopericytomas (HPCs).

STUDY DESIGN

Retrospective case series review.

SETTING

Tertiary referral center.

PATIENTS

Intracranial HPCs within the temporal fossa.

INTERVENTIONS

Craniotomy for either subtotal or gross total tumor excision.

MAIN OUTCOME MEASURES

Determination of clinical outcome (alive with no evidence of disease, alive with disease, and died of disease).

RESULTS

Five cases of HPC involving the temporal fossa were treated at our tertiary referral center for the period from 1995 to 2008. All but 1 patient were men. The age of presentation ranged from 31 to 62 years, and duration of follow-up ranged from 8 to 153 months. Clinical presentation was protean; headache was the most common symptom. Gross total tumor excision was achieved in 2 patients, whereas subtotal tumor excision was achieved in 3 patients. Reasons for subtotal resection included excessive intraoperative blood loss and inextricable tumor. Histologically, all tumors were composed of tightly packed, randomly oriented (jumbled-up) tumor cells with little intervening collagen. CD34 staining mostly highlighted the vascular background. One patient died of disease, 2 patients were alive with disease, and 2 patients had no evidence of disease.

CONCLUSION

Management of temporal fossa HPC is challenging because clinical presentation is often late, and extent of tumor excision is constrained by vital structures in the cranial base and intracranial contents. A multidisciplinary approach with neurosurgery and neurotology undertaken to achieve the most complete tumor resection possible, whereas minimizing morbidity are likely to confer a longer period of symptom-free survival and improves curability of these difficult lesions.

Hemangiopericytoma of thoracic spine: a rare bony tumor

CASE REPORT

We report the case of a 16-year-old girl who developed hemangiopericytoma of the thoracic spine; the main clinical symptoms were of spastic paraparesis with sensory involvement and uro-fecal incontinence. She was initially put on antitubercular treatment keeping in mind the endemicity of tuberculosis in the region. When she deteriorated on conservative management, she was operated upon, and the histopathological report was suggestive of hemangiopericytoma.

MATERIALS AND METHODS

Additional immunocytochemistry was performed in the paraffin-embedded tumor sections.

CONCLUSIONS

An extremely rare case of primary epidural malignant hemangiopericytoma of the thoracic spinal column is described. It is a rare tumor, which is locally aggressive, and a potentially malignant tumor. The tumor is more commonly found in the cranium, and spinal involvement is rare, and only few case reports could be retrieved from the literature. We discuss the clinical profile, management, and outcome of spinal hemangiopericytomas along with pertinent review of the literature.

Intracranial hemangiopericytomas: correlation of topoisomerase IIalpha expression with biologic behavior

BACKGROUND

Meningeal hemangiopericytomas are aggressive tumors that have a high rate of recurrence despite gross total resection and radiation therapy. Topoisomerase, a cell proliferation marker, is also a target of certain chemotherapeutic agents, and its nuclear levels are speculated to predict efficacy of targeted therapy. The aim of this study was to correlate the topoisomerase IIalpha proliferation index (TPI) with biologic behavior in intracranial hemangiopericytomas.

METHODS

Clinical, radiological, and management data in 27 patients with intracranial hemangiopericytoma admitted between 1990 and 2003 were reviewed. Immunohistochemistry was performed on all the tumors using a monoclonal antibody to topoisomerase IIalpha, and the proliferation index was calculated. The effect of TPI on outcome was sought.

RESULTS

The male/female ratio was 15:12. The mean age at presentation was 31.33 years. A radical excision of tumor was done in 18, subtotal excision in 2, partial excision in 4, and a biopsy in 3 patients. Tumor recurrence was noted in 15 (55.6%) of the 27 patients (mean follow-up duration, 51.5 months). The time to recurrence ranged from 7 months to 8 years (mean, 49 months). The 5-year recurrence-free survival was 33.8% in patients with a TPI of 5% or greater, and 72% in patients with a TPI of less than 5%. The relative risk of recurrence was 2.9 times greater in patients with a TPI 5% or greater as compared with those a TPI of less than 5%.

CONCLUSION

Our study suggests that cases with a radical excision, radiation therapy, or a TPI index of less than 5% have a longer recurrence-free survival. A TPI of 5% or greater is a reliable predictor of recurrence.

From the Archives of the AFIP

Primary vascular neoplasms of the spleen constitute the majority of nonhematolymphoid splenic tumors. The benign primary vascular tumors include hemangioma, hamartoma, and lymphangioma, whereas those of variable or uncertain biologic behavior include littoral cell angioma, hemangioendothelioma, and hemangiopericytoma. The primary malignant vascular neoplasm of the spleen is angiosarcoma. Peliosis is a rare lesion of unknown cause that is usually found incidentally in asymptomatic patients but may be associated with hematologic or metastatic disease. Although these vascular neoplasms of the spleen are uncommon, their importance lies in that they must be differentiated from the more common neoplastic disorders of the spleen, such as lymphoma and metastasis. The most common echogenic solid or complex cystic mass in an asymptomatic patient is splenic hemangioma. However, the imaging appearance of splenic hemangiomas may be complex, and differentiation of these lesions from malignant disease may not be possible. The diagnosis of splenic hamartoma may be suggested when findings of increased blood flow on color Doppler images are seen in association with a homogeneous solid echogenic mass. A large subcapsular solitary cystic abnormality discovered incidentally in a child in association with internal septations and tiny mural nodules favors the diagnosis of lymphangioma. Any invasion of the surrounding splenic parenchyma by a splenic lesion should indicate a more aggressive or malignant process. Evaluation of a focal splenic abnormality identified on sonograms should be followed up with computed tomography or magnetic resonance imaging with and without contrast material enhancement. Splenectomy may be required for definitive evaluation of a splenic mass with atypical features.

Hemangiopericytoma of the confluence of sinuses and the transverse sinuses. Case report

The authors describe the case of a 38-year-old man with progressive headache and blurred vision related to a hemangiopericytoma located exclusively in the confluence of sinuses (CoS) and in the transverse sinuses bilaterally. They believe this is the first report in which a hemangiopericytoma of the dural sinuses has been described without any intradural component. Although the diagnosis was not suspected preoperatively, a gross-total resection of the tumor with restoration of sinus patency was achieved to relieve the symptoms. This diagnosis should be included in the preoperative differential diagnosis of a tumor of the CoS. Successful resection can be achieved in these cases.

Sinonasal-type hemangiopericytoma: a clinicopathologic and immunophenotypic analysis of 104 cases showing perivascular myoid differentiation

Sinonasal-type hemangiopericytoma is an uncommon upper aerodigestive tract tumor of uncertain cellular differentiation. We report 104 cases of sinonasal-type hemangiopericytoma diagnosed between 1970 and 1995 from the files of the Armed Forces Institute of Pathology. There were 57 females and 47 males ranging in age from 5 to 86 years (mean 62.6 years). The most common clinical presentation was airway obstruction (n = 57) and/or epistaxis (n = 54), with symptoms averaging 10 months in duration. The tumors involved the nasal cavity alone (n = 47) or also a paranasal sinus (n = 26), were polypoid, and measured an average of 3.1 cm. Histologically, the tumors were submucosal and unencapsulated and showed a diffuse growth with fascicular (n = 37) to solid (n = 50) to focally whorled (n = 7) patterns. The tumor cells were uniform in appearance with minimal pleomorphism and had spindle-shaped (n = 82) to round/oval (n = 18) nuclei with vesicular to hyperchromatic chromatin and eosinophilic to amphophilic to clear-appearing cytoplasm with indistinct cell borders. Multinucleated (tumor) giant cells were identified in a minority of cases (n = 5). Mitotic figures were inconspicuous and necrosis was absent. The tumors were richly vascularized, including staghorn-appearing vessels that characteristically had prominent perivascular hyalinization (n = 92). An associated inflammatory cell infiltrate that included mast cells and eosinophils was noted in the majority of cases (n = 87). The immunohistochemical profile included reactivity with vimentin (98%), smooth muscle actin (92%), muscle specific actin (77%), factor XIIIa (78%), and laminin (52%). Surgery was the treatment of choice for all of the patients; adjunctive radiotherapy was given to four patients. Recurrences developed in 18 patients within 1-12 years from diagnosis. Ninety-seven patients were either alive (n = 51, mean 16.5 years) or dead (n = 46, mean 9.6 years) but free of disease. Four patients had disease at the last follow-up: three died with disease (mean 3.6 years) and one patient is alive with disease (28.3 years). Recurrent tumor (17.8%) can be managed by additional surgery. The majority of sinonasal-type hemangiopericytomas behave in a benign manner with excellent long-term prognosis (88% raw 5-year survival) following surgery alone. Sinonasal-type hemangiopericytomas have a characteristic light microscopic appearance with an immunophenotypic profile resembling that of glomus tumors.

Hemangiopericytoma in the central nervous system: treatment, pathological features, and long-term follow up in 38 patients

OBJECT

The authors reviewed the Mayo Clinic experience with the treatment of hemangiopericytoma in the primary central nervous system (CNS).

METHODS

A retrospective study of all patients at the Mayo Clinic revealed 38 who had been treated for hemangiopericytoma in the CNS. Twenty of these patients were diagnosed in the decade between 1990 and 2000; 18 were initially diagnosed and underwent surgery before 1990. In the patients treated since 1990, the 5-year Kaplan-Meier survival rate was 93%. The 5-year disease-free survival rate was 89%. Sixty percent of patients treated with the aid of stereotactic radiosurgery for recurrent disease were alive 4.4 years after their initial treatment. Salvage chemotherapy was not effective. No survival benefit was detected inpatients who had received initial adjuvant external-beam radiation therapy. High-grade tumors recurred 6.7 years earlier than did low-grade lesions (p = 0.004).

CONCLUSIONS

The 5-year survival rate in patients with hemangiopericytoma of the CNS has improved at the authors' institution during the last 10 years. Although the reason for this is not entirely clear, the authors suspect that the improved treatment of patients with cancer, a 0% intraoperative mortality rate, and the use of radiosurgery in the treatment of recurrent disease all likely contribute. High-grade tumors recurred statistically significantly earlier than low-grade lesions. Current chemotherapies are ineffective in the treatment of hemangiopericytoma of the CNS.

True hemangiopericytoma of the nasal cavity

Two cases of nasal tumors with pericytic myoid differentiation are reported. The tumors occurred in a 77-year-old woman and a 60-year-old man as polypoid lesions covered by normal mucosa. Histologically, the tumors were composed of uniform short spindle or stellate cells with indistinct cell borders arranged in narrow and short fascicles. Numerous blood vessels of various sizes were common in both cases. The tumor cells of both cases stained intensely with anti-vimentin and anti-actin antibodies, but not with anti-desmin, CD34, or anti-high-molecular-weight caldesmon antibodies. Ultrastructural examination revealed well-developed actin thin filaments with dense bodies, subplasmalemmal plaques, intercellular junctions, and irregular discontinuous basement membranes. These histopathologic features suggest true pericytic differentiation of the tumors (true hemangiopericytoma), unlike soft tissue-type hemangiopericytoma. Generally, sinonasal hemangiopericytomas are subdivided into soft tissue-type hemangiopericytomas and true hemangiopericytomas identical to the cases presented here. Soft tissue-type hemangiopericytomas are frequently highly aggressive, whereas true hemangiopericytomas show localized benign behavior. Sinonasal true hemangiopericytomas should be strictly differentiated from soft tissue-type hemangiopericytomas.

Connective tissue growth factor expression in pediatric myofibroblastic tumors

Human connective tissue growth factor (CTGF) is a secreted cysteine-rich peptide and a member of the peptide family that includes serum-induced immediate gene products such as a v-src-induced peptide and a putative proto-oncogene, c-src. CTGF is secreted by endothelial cells, fibroblasts, smooth muscle cells, and myofibroblasts. Its expression is increased in various human and animal fibrotic diseases. We hypothesized that tumors with significant fibrous and vascular components would exhibit increased expression of CTGF. We examined the expression of CTGF mRNA by in situ hybridization in 12 pediatric tumors and tumor-like conditions, including angiofibroma, malignant fibrous histiocytoma, infantile myofibromatosis, and malignant hemangiopericytoma. All the tumors showed moderate to intense CTGF expression in tumor cells and/or endothelial cells of the associated vasculature. Angiofibromas expressed CTGF only in factor VIII-positive endothelial cells and vascular smooth muscle cells. In contrast, infantile myofibromatosis, malignant hemangiopericytomas, and fibrous histiocytomas expressed CTGF in both endothelial cells and in vimentin-positive tumor cells, particularly those around the blood vessels. CTGF mRNA was not detected in the inflammatory cells observed in many of the tumors. The presence of CTGF in the endothelial cells and tumor cells around blood vessels raises the possibility that CTGF is involved in the pathogenesis of these myofibroblastic tumors.

Fine-needle aspiration cytology of hemangiopericytoma: report of two cases

The fine-needle aspiration biopsy (FNAB) findings in two cases of hemangiopericytoma (HP), arising in the parotid gland and on the inner chest wall, respectively, are reported. Smear preparations in each case showed cytologic features of an undifferentiated spindle-cell neoplasm, whereas a core needle biopsy specimen of the chest wall mass showed a spindle-cell tumor with a "staghorn-like" arrangement of endothelium-lined vascular channels. Immunostains performed on this core biopsy, and on the surgical resection specimens in both cases, showed positive staining of tumor cells for vimentin and CD34, with negative staining for a variety of smooth muscle, epithelial, neural, and neuroendocrine markers. Electron microscopy performed in one case further supported the diagnosis of HP. With adequate sampling and appropriate use of ancillary studies, a diagnosis of HP can be reliably suggested on the basis of FNAB and core biopsy of a soft-tissue mass.

Hemangiopericytoma in children and infants

BACKGROUND

Hemangiopericytoma (HPC) is a soft-tissue neoplasm most commonly seen in adults; only 5-10% of cases occur in children. Childhood HPC comprises two distinct clinical entities. In children older than 1 year, it behaves in a manner similar to adult HPC. Infantile HPC, however, although histologically identical to adult HPC, has a more benign clinical course. The reasons for these differences in the natural history of HPC are not well understood.

METHODS

The authors reviewed the clinicopathologic features of HPC as well as the treatment and outcomes of the 12 children (9 males and 3 females) treated for this disease at St. Jude Children's Research Hospital over a 35-year period.

RESULTS

At diagnosis, 9 patients were older than 1 year and 3 were younger than 1 year. Among the 9 older patients, tumors were most commonly found in the lower extremities (n = 5). One patient had been treated for acute lymphoblastic leukemia 15 years earlier. One patient had metastatic disease at diagnosis, and three had unresectable tumors. Two patients experienced objective responses to chemotherapy. Three patients died of disease progression. Among the three infants, two had unresectable disease at diagnosis, and both experienced excellent responses to neoadjuvant chemotherapy. In one case, the response of the tumor to chemotherapy correlated with maturation to hemangioma. All three infants are alive without evidence of disease.

CONCLUSIONS

HPC in children older than 1 year does not differ from adult HPC, and aggressive multimodality therapy is required. Infantile HPC, on the other hand, is characterized by better clinical behavior, with documented chemoresponsiveness and spontaneous regression, and requires a more conservative surgical approach. In some cases of infantile HPC, this benign behavior correlates with maturation to hemangioma.

Nasal haemangiopericytoma: report of two cases with literature review

Haemangiopericytoma (HPC) is a rare vascular tumour produced by proliferation of pericytes. One hundred and thirty-three cases of HPC have been reported in the nose and the paranasal sinuses. We present two more cases. Wide surgical excision via lateral rhinotomy, midfacial degloving, or endonasal removal is the treatment of choice. Radiotherapy has been used post-operatively in cases of incomplete removal. Life-long follow-up is required to evaluate local recurrence and late metastases.

The histological spectrum of hemangiopericytoma: application of immunohistochemical analysis including proliferative markers to facilitate diagnosis and predict prognosis

Hemangiopericytoma (HPC) is an uncommon vascular neoplasm thought to be derived from pericytes. Prediction of patient outcome is difficult based what is currently known about these tumors and histological parameters alone. We compiled 27 cases of HPC and evaluated the spectrum of histological features to investigate whether there was any correlation between histology, immunostaining, prognostic markers, and patient outcome. The following parameters were evaluated: vasculature, histological pattern (solid, myxoid, trabecular, alveolar), degree of cellular pleomorphism, necrosis, mitoses, and giant cell content. Immunohistochemistry was performed to determine the reactivity for CD 31, CD34, vimentin, actin, cytokeratin, S100, actin, and SMA. Proliferative rate was analyzed using antibodies to PCNA and MIB1. Patient's age ranged from 8 months to 75 years (mean, 35; median, 31). Twenty of 27 cases were located in the extremities. The tumors were grossly described as lobulated and well circumscribed (n=12) and nonencapsulated (n=15). By histology, the characteristic ramifying or staghorn vasculature pattern was seen in all cases. A solid histological pattern was mixed with an alveolar pattern in three cases, trabecular pattern in six cases, and myxoid pattern in two cases. Tumor cells were uniform, polygonal to spindle-shaped, often with vesicular nuclei. Tumor giant cells were present in 9 of 27 cases; necrosis, in 11 of 27. Mitoses ranged from 0 to 14 per 10 high-power fields (HPF). Cellular pleomorphism was 1+ in nine cases, 2+ in 12 cases, and 3+ in six cases. Immunohistochemistry showed reactivity for CD34 and vimentin in all cases. Actin was focally positive in one case, and SMA was focally positive in another. CD 31, cytokeratin, and S100 were uniformly nonreactive. Proliferative index measured by PCNA and MIBI ranged between less than 1% and 40% of tumor cells. Follow-up was available in 22 cases and ranged from 1 year to 15 years. Seven patients had metastases, and two recurred locally. Thirteen patients had no evidence of disease at last checkup. Parameters associated with recurrences or metastases include a trabecular pattern, the presence of necrosis, mitoses, vascular invasion, and cellular pleomorphism. Features associated with an aggressive biological behavior can be identified histologically. There was some, but not total, correlation between proliferative markers and tumor aggressiveness.

Hemangiopericytoma: a 20-year single-institution experience

BACKGROUND

Hemangiopericytoma is an uncommon soft tissue sarcoma. We sought to evaluate the long-term outcome of a consecutively treated patient cohort with hemangiopericytoma.

METHODS

The study involved 36 adult patients (older than 16 years) with hemangiopericytoma treated at The University of Texas M. D. Anderson Cancer Center between July 1975 and July 1995. Data on clinicopathologic parameters, surgical treatment, adjuvant therapy, disease recurrence, and survival were obtained from a review of medical records.

RESULTS

The median follow-up was 57 months. Twenty-eight patients (78%) underwent complete and potentially curative resection of their primary disease. Of the nine patients (32%) who had local recurrences, four (57%) had epidural tumors and three (43%) had retroperitoneal tumors, but none had extremity tumors. Extremity tumors were associated with a significantly prolonged local recurrence-free survival compared to tumors at nonextremity anatomic sites (P <.05). Ten patients had recurrences at distant sites. Of the 13 patients who experienced any form of disease recurrence, four had recurrences after a disease-free interval of more than 5 years. The 5-year actuarial survival rate for the entire group of 36 patients was 71%. Noncurative surgical treatment (P=.007) and development of distant metastatic disease (P=.013) were associated with shortened survival.

CONCLUSION

Extended survival is common in hemangiopericytoma patients treated with curative intent. However, local and distant recurrences may occur after a prolonged disease-free interval, emphasizing the need for long-term follow-up. Retroperitoneal and meningeal tumors were associated with higher local recurrence rates; therefore, adjuvant therapies should be considered and evaluated for tumors at these sites.

Radiotherapy of bone metastases of a spinal meningeal hemangiopericytoma

Hemangiopericytoma is a rare tumor arising from pericapillary cells or pericytes of Zimmerman, and can occur anywhere capillaries are found. We describe a patient with a meningeal hemangiopericytoma who was treated with primary surgical resection and experienced multiple bone metastases 20 years after the first treatment. This patient with multiple bone metastases was treated with multiple courses of irradiation and good palliation was achieved.

Leiomyomatous nodules and bundles of vascular origin in the fibrosarcomatous variant of dermatofibrosarcoma protuberans

We report 5 cases of the fibrosarcomatous variant of dermatofibrosarcoma protuberans, 4 of which presented a morphologic change of intraneoplastic blood vessels not previously recognized. This change consisted of focal proliferation of smooth muscle cells, resulting in hypertrophy, generally eccentric, of vascular walls with reduction and collapsing of vascular lumina. In 3 cases the proliferation was so intense it formed leiomyomatous nodules and bundles. This proliferation may originate in the smooth muscle cells of the vessel walls either by means of a hyperplastic mechanism or in the pericytes via a line of differentiation leading to mature smooth muscle cells. In either case, we believe that it concerns a reactive process of the vessel walls very probably induced by adjacent neoplastic cells. The cases recently reported by Calonje and Fletcher as "myoid differentiation" of neoplastic cells in dermatofibrosarcoma protuberans (DFSP) may well be an expression of the same phenomenon, and therefore the presence of leiomyomatous areas in this tumor should not be used to support the theory of a fibroblastic/myofibroblastic line of differentiation for DFSP.

Cutaneous vascular proliferation. Part II. Hyperplasias and benign neoplasms

This second part of our review about vascular proliferations summarizes the clinicopathologic features of the cutaneous vascular hyperplasias and benign neoplasms. Hyperplasias comprise a heterogeneous group of vascular proliferations that eventually show a tendency to regression. Angiolymphoid hyperplasia with eosinophilia is included within the group of hyperplasias because of its historical denomination and its reactive nature, probably as a consequence of an arteriovenous shunt, although usually the lesions do not regress. Pyogenic granuloma, bacillary angiomatosis, intravascular papillary endothelial hyperplasia, and pseudo-Kaposi's sarcoma qualify as vascular hyperplasias because they regress when the stimulus that initiated them is removed. Benign neoplasms form a large group of hemangiomas with distinctive clinicopathologic characteristics, although some of them are of recent description and may produce diagnostic difficulties. We classified cutaneous benign vascular neoplasms according to their cell lineage of differentiation, for example, endothelial, glomus cell, and pericytic differentiation. Subsequent categories are established according to the size of the involved vessels (capillaries, venules and arterioles, or veins and arteries) or the nature of the proliferating vessels (blood or lymphatic vessels). Capillary and cavernous hemangiomas have been the terms classically used to name the most common variants of benign vascular neoplasms (i.e., infantile hemangiomas), but they are not the most appropriate denominations for these lesions. First, these names are not contrasting terms. Furthermore, most of the socalled "cavernous" hemangiomas are not hemangiomas (neoplasms) at all, but venous malformations. The most important conceptual issue is that, at any point in time, a particular hemangioma has its own histopathologic pattern throughout the depth of the lesion. For these reasons, we classified hemangiomas into superficial and deep categories. Some of the lesions reviewed have been recently described in the literature, and they may histopathologically mimic lesions of Kaposi's sarcoma; these include targetoid hemosiderotic hemangioma, microvenular hemangioma, tufted hemangioma, glomeruloid hemangioma, kaposiform hemangioendothelioma, spindle-cell hemangioendothelioma, and benign lymphangioendothelioma. In each of these lesions, we update and emphasize those clinical and histopathologic features that are helpful for differential diagnosis with lesions of authentic Kaposi's sarcoma in any of its three stages of development (patch, plaque, or nodule).

Orbital hemangiopericytoma: clinical and morphologic features

PURPOSE

To report the clinical and histopathologic features of orbital hemangiopericytoma.

METHOD

We review the clinical and histopathologic features in seven patients.

RESULTS

Ultrasonography, computed tomography, and magnetic resonance imaging defined the location and extent of the tumor in each patient but did not disclose pathognomonic features for the specific diagnosis of hemangiopericytoma. The predominating histopathologic feature of each tumor was a mixed pattern of ovoid cells and sinusoidal space formations. Five patients showed mild to severe cellular atypia; three had obvious pleomorphism and increased number of abnormal mitotic figures. Tumor cells disclosed cytoplasmic reactivity for vimentin but in five cases were negative for other immunologic markers. Six patients received surgical treatment with an attempt for total removal of the tumor; one had biopsy and radiation therapy. In two patients, radiation therapy was given in addition to tumor removal with orbital exenterations. Three patients died with recurrent and metastatic disease, and four patients are alive without tumor for a follow-up period ranging from 3 to 9 years.

CONCLUSIONS

Orbital hemangiopericytoma may behave as a malignant tumor, leading to local recurrence or metastasis, or both. Clinical and histopathologic findings should be considered jointly to evaluate the clinical course; histopathologic findings alone are not sufficient to predict the biologic behavior of this tumor.

Congenital hemangiopericytoma/infantile myofibromatosis: radical surgery versus a conservative "wait and see" approach

Infantile/congenital hemangiopericytoma, although sharing many similar histological features with adult hemangiopericytoma, has a much better prognosis. Nevertheless, most cases described in the literature were pursued by radical surgery with or without adjuvant chemotherapy. We describe a neonate who presented with a huge mass in the right gluteus, 6 x 5 x 4 cm, and a small ventral abdominal mass. The masses were confirmed on biopsy according to light microscopy, immunohistochemistry, and electron microscopy as congenital hemangiopericytoma. They shrank spontaneously within 2 weeks and vanished within 2 months. We present a hypothesis that masses appearing in the neonatal period with this histology and with no life-endangering pressure on vital organs should routinely be dealt with conservatively.

Cutaneous adult myofibroma: a vascular neoplasm

Infantile myofibromatosis is a distinctive type of fibromatosis that usually develops during the immediate perinatal period. There are variants with solitary and multiple tumors. Lesions confined to the skin, soft tissue, and bone carry a good prognosis, showing spontaneous regression. The prognosis, however, is much less favorable when visceral lesions are present and the outcome may be fatal. Only recently it became obvious that there is an adult counterpart of infantile myofibromatosis, characterized by solitary lesions that have a predilection for involve the dermis and show no tendency to regression, although they have an entirely benign biological behavior. These lesions have been named cutaneous myofibroma or solitary myofibroma of adults. We have studied the clinical, histopathological and immunohistochemical characteristics of 53 examples of cutaneous adult myofibroma. In addition, 2 cases were examined ultrastructurally. The patients were mostly adults with ages ranging from 6-83 years. The lesions presented as solitary, usually painless nodules of variable duration on the skin, usually located on the extremities. Histopathologically, four patterns were identified: nodular or cellular type, multinodular or biphasic type, leiomyoma-like or fascicular type, and vascular type. A correlation between the histopathologic pattern and the lesional age was observed: vascular type of cutaneous adult myofibroma in early lesions, nodular and multinodular lesions in fully developed lesions, and leiomyoma-like or fascicular type in late lesions. Immunohistochemically, the spindle cells were desmin negative, but expressed immunoreactivity for vimentin, pan-smooth muscle actin, and alpha-smooth muscle actin. Ultrastructurally, neoplastic cells showed characteristics of undifferentiated mesenchymal cells with features of fibroblasts, myofibroblasts and pericytes. Primitive vascular formations were seen in the form of irregular clefts between adjoining cells. We conclude that cutaneous adult myofibroma is a little-known benign vascular neoplasm probably derived from myopericytes.

Are infantile myofibromatosis, congenital fibrosarcoma and congenital haemangiopericytoma histogenetically related?

Infantile myofibromatosis, congenital fibrosarcoma and congenital/infantile haemangiopericytoma are generally considered distinct entities. Overlapping microscopic features between infantile myofibromatosis and congenital fibrosarcoma, and between infantile myofibromatosis and congenital/infantile haemangiopericytoma, however, have been noted, but not formally reported. This report concerns six neonatal tumours, each exhibiting more than one of the above patterns, supporting a histogenetic relationship among these entities. Immunohistochemistry for smooth muscle actin was found to be useful in the diagnosis of congenital/infantile haemangiopericytoma, and also served to support a histogenetic relationship with the other two entities under consideration.

Fibrohistiocytic differentiation in capillary hemangioblastoma

Seven cases of capillary hemangioblastoma from the cerebellum and spinal cord were studied by immunohistochemical methods to determine the origin of the stromal cells. A subpopulation of factor XIIIa-positive tumor cells was a constant feature in hemangioblastomas. These stellate or spindle-shaped cells transformed into typical vacuolated stromal cells. Factor VIII-related antigen was limited to the vascular endothelium. Glial fibrillary acidic protein was present only in entrapped astrocytes. Staining for alpha-1-antitrypsin (alpha 1AT) and alpha-1-antichymotrypsin (alpha 1 ACT) was occasionally observed in stromal cells. It was concluded that the factor XIIIa-positive stromal cells in capillary hemangioblastoma indicate fibrohistiocytic differentiation, which is part of the differentiation spectrum of hemangiopericytomas.

Intraoral infantile hemangiopericytoma: literature review and addition of a case

A rapidly growing neoplasm in the buccal mucosa of a 4-month-old baby was excised. By light and electron microscopy the neoplasm had features that were similar to those described in infantile hemangiopericytoma, a rare neoplasm of vascular origin. By light microscopy the neoplasm was multilobular with highly proliferating round to spindle-shaped cells interspersed with numerous vascular spaces. Ultrastructurally, round to elongated cells with short processes, pinocytotic vesicles, reduplicated basal lamina, and basal lamina-like material were identified. Immunohistochemically the cells were weakly positive with antibodies to vimentin, focally positive with HHF-35, a smooth-muscle cell antibody, negative with antibodies to S-100 protein, T-200, neuron-specific enolase, neurofilaments, desmin, and cytokeratins 35BH11 and 34BE12. Blood vessels were positive with Ulexeuropaeuslectin, but tumor cells were negative. Reticulin stain decorated a delicate network of fibrils surrounding tumor cells and vascular spaces. Clinically the neoplasm did not recur and the baby has been disease free for more than 26 months. The difficulty of the histologic diagnosis of this neoplasm is discussed and the literature is reviewed, with special emphasis on lesions occurring in the oral cavity.

Differentiation markers in hemangiopericytoma

Normal pericytes were found to express factor XIIIa (F-XIII) and histocompatibility antigen HLA-DR. These markers were studied in 15 hemangiopericytomas (HPC) and 16 other tumors with an HPC-like pattern. A subpopulation of tumor cells expressing F-XIII and HLA-DR antigens was a constant feature of HPC and supported their pericytic origin. Meningeal HPC did not differ in phenotype from peripheral soft tissue HPC. Most tumors with an HPC-like pattern (including synovial sarcomas, malignant schwannomas, leiomyosarcomas, and liposarcomas) were negative for F-XIII and HLA-DR. Malignant fibrous histiocytomas, however, invariably contained a subpopulation expressing these antigens. Therefore, F-XIII can be considered as a marker of fibrohistiocytic differentiation in HPC. Individual tumor cells in HPC occasionally were positive for factor VIII-related antigen (F-VIII-R-Ag), suggesting that the spectrum of differentiation in HPC may include the endothelial cell line. The differentiation characteristics of HPC support the concept that pericytes are primitive cells that may act as precursors to other mesenchymal cells.

Nasal haemangiopericytoma

Haemangiopericytoma is an uncommon vascular tumour frequently diagnosed with difficulty. The immunohistochemical findings of strong positivity to vimentin together with other diagnostic features (histological and ultrastructural) improves the certainty of its diagnosis. We report a case arising in the nose and outline diagnostic problems especially relating to histopathology.

Retroperitoneal sarcoma with features suggestive of alveolar soft part sarcoma

A 72-year-old man presented with a 15 x 12 x 5 cm cystic and necrotic tumor involving the superior region of the stomach and the retroperitoneum down to the transverse colon and extending laterally from the left lobe of the liver to the spleen without involving either organ. Light microscopy showed the tumor cells to be arranged in an organoid pattern. Immunocytochemistry showed a strong reaction for desmin and vimentin. Electron microscopy demonstrated features suggestive of an alveolar soft part sarcoma.

Hemangiopericytoma: characteristic features observed by magnetic resonance imaging and angiography

Hemangiopericytoma is a rare vascular tumor which may originate wherever there are capillaries. We report a case of this tumor occurring in a 79-year-old Japanese man, which originated from the subcutaneous tissues of the left upper arm and reached a size of 6 x 5 x 4 cm. Histopathological and electron microscopical findings were compatible with those of benign-type hemangiopericytoma. Magnetic resonance imaging showed the most intense signal on proton density images. Angiography showed the characteristic tumor feeder artery forming a pedicle which entered the tumor and branched radially and a dense, uniform, well-demarcated, oval tumor stain. These images were helpful in performing proper operative treatment without noteworthy bleeding. These modern modalities are excellent non-invasive treatment without diagnostic procedures for the vascular tumors of soft tissues in dermatology.

Malignant haemangiopericytoma of lung: a cell culture and ultrastructural study

Malignant haemangiopericytoma was grown in vitro to assess the histogenesis of the tumour. Disaggregated tumour cells maintained in serum-supplemented Waymouth's MB 752/1 medium showed monolayers of homogeneous spindle cells. Post-confluent cultures exhibited hillocks or plaques of multilayer growth within which considerable amount of basal lamina-like material and fibrillar matrix were present between cells. Delicate basal laminae were also expressed on cell surfaces facing matrix material. Other consistent features were attenuated cytoplasmic processes, desmosome-like junctions, abnormal mitochondria and a paucity of intracellular filaments. The three-dimensional organization of tumour cells with concomitant expression of differentiated phenotype in vitro has significant implications on the cell of origin and differentiation process of haemangiopericytoma.

Hemangiopericytoma--the role of radiotherapy

Between 1955 and 1987, 15 patients with hemangiopericytomas were seen at the University of Iowa Hospitals and Clinics. Twelve of these were thought to have localized tumors and three had metastatic disease at diagnosis. Seven of the 12 patients with localized disease were treated with surgery alone, four were treated with surgery and postoperative radiation therapy, and one was treated with surgery and chemotherapy. Only one of the seven patients initially treated with surgery alone has remained continuously free of disease, although two others were salvaged with radiation therapy. In contrast, all four patients initially treated with surgery and postoperative radiation therapy have remained alive with no evidence of disease in spite of the fact that three of these patients had gross residual tumor at the time of irradiation. Ten patients received radiation therapy at some stage of their management. Local tumor control was achieved at all sites receiving greater than 5500 cGy. Six patients received chemotherapy sometime during the course of their management, although no complete or partial responses were observed. In this small series, mitotic activity was not an accurate predictor of biologic behavior.

So-called minute chemodectoma of the lung. An electron microscopic and immunohistochemical study

So-called minute pulmonary chemodectoma is a curious, small lung tumour found mainly in women. The nature and origin of the proliferating cells are still obscure. In the first report on the tumour, the component cells were described as resembling chemoreceptor cells and the tumour was named chemodectoma. However, electron microscopic studies of the tumour have revealed no evidence of neuronal characteristics and have shown a close resemblance to meningothelial cells. In this study, the electron microscopic findings were similar to those previously reported but in one of the two cases, tumour cells were filled with abundant cytofilaments, giving them an occasional dense, patch-like appearance. Immunostaining for myosin and vimentin was positive in all tumour cells, but epithelial membrane antigen staining was not seen. These findings indicate that the tumour might have its origin from muscle cells.

Histogenesis of intracranial haemangiopericytoma and haemangioblastoma. An immunohistochemical study

An immunohistochemical study was performed on three meningeal haemangiopericytomas and four cerebellar haemangioblastomas (paraffin embedded) in an attempt to elucidate the uncertain histogenesis of these tumours. The tumour cells of all meningeal haemangiopericytomas show no expression of alpha-smooth muscle actin and, thus, no immunohistochemical proof of their true pericytic nature can be obtained. The stromal cells of cerebellar haemangioblastomas show foci of positive staining for S-100 protein, neuron-specific enolase and synaptophysin, thereby clearly indicating their neuroectodermal origin. These results allow the conclusion that the present nomenclature of these tumours is at least arguable and probably incorrect.