Sinonasal haemangiopericytoma-like tumour: a sinonasal glomus tumour or a haemangiopericytoma?

Integrated Molecular and Histological Insights for Targeted Therapies in Mesenchymal Sinonasal Tract Tumors

PURPOSE OF REVIEW

This review aims to provide a comprehensive overview of mesenchymal sinonasal tract tumors (STTs), a distinct subset of STTs. Despite their rarity, mesenchymal STTs represent a unique clinical challenge, characterized by their rarity, often slow progression, and frequently subtle or overlooked symptoms. The complex anatomy of the sinonasal area, which includes critical structures such as the orbit, brain, and cranial nerves, further complicates surgical treatment options. This underscores an urgent need for more advanced and specialized therapeutic approaches.

RECENT FINDINGS

Advancements in molecular diagnostics, particularly in next-generation sequencing, have significantly enhanced our understanding of STTs. Consequently, the World Health Organization has updated its tumor classification to better reflect the distinct histological and molecular profiles of these tumors, as well as to categorize mesenchymal STTs with greater accuracy. The growing understanding of the molecular characteristics of mesenchymal STTs opens new possibilities for targeted therapeutic interventions, marking a significant shift in treatment paradigms. This review article concentrates on mesenchymal STTs, specifically addressing sinonasal tract angiofibroma, sinonasal glomangiopericytoma, biphenotypic sinonasal sarcoma, and skull base chordoma. These entities are marked by unique histopathological and molecular features, which challenge conventional treatment approaches and simultaneously open avenues for novel targeted therapies. Our discussion is geared towards delineating the molecular underpinnings of mesenchymal STTs, with the objective of enhancing therapeutic strategies and addressing the existing shortcomings in the management of these intricate tumors.

Sinonasal Glomangiopericytoma with Skull Base Involvement: A Diagnostic Dilemma

Introduction: Glomangiopericytoma (GPC) is a rare type of neoplasm with hemangiopericytoma-like vasculature and perivascular hyalinization of capillary-sized veins. CD34 and S100 protein staining might be positive in a small percentage of GPC. Solitary fibrous tumors (SFTs) present clinically like GPC. However, challenges remain when differentiating GPC from SFT. Case Presentation: A 37-year-old male, smoker, presented with 3 years history of right-sided epistaxis and nasal congestion. He was also complaining of hyposmia but no headaches or visual complaints. On nasal endoscopy, he was found to have a right-sided nasal mass occupying the ethmoid cavity. Computed tomography showed a right sinonasal mass abutting the anterior skull base and magnetic resonance imaging demonstrated a hyperintense, enhancing mass within the right ethmoid cavity, superior septum, and anterior skull base. The patient underwent endoscopic resection with gross total resection and skull base reconstruction. Postoperative pathology initially was thought to be an SFT; however, subsequent STAT6 expression was negative, and therefore GPC diagnosis was confirmed. At the most recent follow-up (6 months), the patient remained free of local disease. Discussion: SFT, unlike GPC, stains strongly for CD34, in this case, due to strong CD34, the diagnosis of SFT was initially made. Nuclear STAT6 expression is highly specific and sensitive for SFT. This later returned as negative; therefore, GPC was confirmed. Conclusion: We present a case of sinonasal GPC with skull base involvement that was treated with endoscopic resection. At the most recent follow-up (6 months), the patient remained free of local disease.

Unveiling a Rarity: A Case Report on Glomangiopericytoma in the nasal cavity

Sino-nasal glomangiopericytoma is a rare benign tumour comprising only about 0.5% of all sino-nasal tumours. Presenting as a bleeding nasal mass, it is among the myriad of differential diagnoses for the same. Clinical characterisation of mass becomes difficult; hence, histopathology and immunohistocytochemistry play an essential role in clenching the diagnosis. Optimal treatment includes complete tumour excision with endoscopic or open approaches with or without preoperative embolization and a long post-operative follow-up period. Here we report such a case treated with endoscopic approach.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03975-z.

Clinical and histopathological findings of a rare sinonasal glomangiopericytoma

Glomangiopericytoma is a rare vascular neoplasm of the nasal cavity and paranasal sinuses that occurs during the sixth or seventh decade of life. It is categorized as a borderline tumor with low malignant potential and classified as a distinct entity of sinonasal tumors with perivascular myoid phenotype by the World Health Organization (WHO). We report the case of a 50-year-old woman with nasal obstruction and severe epistaxis. The nasal sinuses computed tomography (CT), and magnetic resonance imaging (MRI) demonstrated a 3.1 cm soft tissue mass occupying the upper part of the left nasal cavity invading the left paranasal sinuses and nasal septum, and the left eye medial rectus muscle. A total mass resection was performed by nasal endoscopy. The histological and immunohistochemical examination yielded the diagnosis of glomangiopericytoma. This case report aims to contribute to the knowledge of nasal neoplasms. The need for more data on this entity is the main obstacle to developing standardized treatment guidelines.

Endoscopic Excision of Sino Nasal Hemangiopericytoma

Hemangiopericytomas (HPCs) are rare vascular tumours originating from extra capillary cells called Zimmermann's pericytes. Only 5% of these lesions occur in the Sino nasal cavity. Sino nasal HPCs have a benign course with a high recurrence rate ranging from 9.5 to 50%. A radical surgical resection is considered the gold standard treatment either via external approach (lateral rhinotomy or Caldwell-Luc) or endoscopic approach. Three cases of Sino nasal hemangiopericytomas were treated at our institute. All these cases were operated via endoscopic approach. We are reporting their diagnostic work-up and the therapeutic management as case series. We also discuss epidemiological, clinical, morpho-pathological and radiological characteristics of this tumoral pathology. A treatment plan is also elucidated which may help to develop a long term treatment protocol for these lesions.

Sinonasal haemangiopericytoma- An unusual swelling in the nasal cavity

Sinonasal hemangiopericytoma, also known as glomangiopericytoma (GPC) is a benign perivascular tumor of low malignant potential, with an incidence rate of 0.5-1% of all sinonasal tumors. It often shows local recurrences with invasion to the surrounding bony tissues. It usually arises from the perivascular cells surrounding the capillaries. Etiology of the tumour is uncertain, with few postulated hypothesis like pregnancy, trauma, hypertension and corticosteroid drugs. They have an indolent course and tend to occur most commonly in the adults of seventh decade of life. We present a case report of 55 years old male presenting to the ENT OPD, with complaints of right sided nasal obstruction and repeated episodes of epistaxis since the last 9 months. History and general examination was unremarkable except for anti-hypertensive intake since the last few years. Laboratory investigations showed microcytic hypochromic anaemia, raised absolute eosinophil count of 1500 cells per microliter and positive Hepatitis B surface antigen (HBsAg) in the blood. Rhinoscopic examination showed a reddish brown nodular swelling in the right nasal cavity beneath the middle turbinate and hypertrophy of left nasal mucosa. CT imaging suggested an 18x15 mms, well defined soft tissue mass in the right nasal cavity. Complete resection of the mass with endoscopic surgery was performed. Histopathological examination coupled with immunohistochemistry confirmed the diagnosis of Sinonasal Hemangiopericytoma. This case report stresses upon various differential diagnosis of sinonasal swellings and the importance of considering long term follow up of Sinonasal Hemagiopericytoma.

Variability of CD34 Expression in Sinonasal Glomangiopericytoma: A Potential Diagnostic Pitfall

Sinonasal glomangiopericytoma (GPC) is an uncommon primary sinonasal neoplasm showing a perivascular myoid differentiation. Originally perceived as an intranasal counterpart to soft tissue hemangiopericytomas, initial immunohistochemical reports showed mostly negative to focal weak reactivity for CD34 as useful in separating GPC (almost always benign) from morphologic mimics, mainly solitary fibrous tumor (potentially aggressive). In anecdotally encountering cases of GPC with CD34 reactivity beyond the expected weak/negative immunoprofile, we sought to formally evaluate CD34 staining in 10 cases of GPC from two different vendors in conjunction with a meta-analysis of other GPC series reporting CD34 staining. Ten cases of GPC were retrieved from the authors' pathology archives (left nasal cavity = 7, right nasal cavity = 3; 5 men, 5 women; average age 59.0 years with range of 43-77 years). Follow-up showed no evidence of disease after complete resection from all 10 cases (average follow-up length of 53.3 months, range 6-106 months). All 10 GPC cases (100%) showed positivity using CD34 from Leica (QBend10 clone), with most showing moderate to diffuse staining intensity and moderate extent, while only 2 of 10 cases (20%) showed positivity using CD34 from Ventana (QBend10 clone), with both positive cases showing weak staining intensity and focal extent. Literature review of other studies (reporting ≥ 5 GPC cases) found a wide spectrum of CD34 positivity ranging from 0 to 100%; including our GPC cases, CD34 showed a cumulative positivity of 28%. Although negative CD34 reactivity has been historically regarded as prototypic for GPC, in this study we have exposed laboratory variability in CD34 expression and have shown that reliance on expected negative reactivity in GPC can be a clinically relevant diagnostic pitfall. Our findings suggest a panel approach in selecting diagnostic immunostains rather than relying on CD34 alone in the assessment of spindle cell neoplasms in the sinonasal tract with admixed prominent staghorn-like vasculature.

β-catenin (CTNNB1) mutation and LEF1 expression in sinonasal glomangiopericytoma (sinonasal-type hemangiopericytoma)

Sinonasal glomangiopericytoma (SN-GPC) is an uncommon mesenchymal tumor with myoid differentiation. Recently, mutations in exon 3 of the gene coding for β-catenin (CTNNB1) and its nuclear expression were discovered in SN-GPC. β-catenin protein is a key regulatory molecule of the canonical Wnt signaling pathway. The expression of β-catenin target proteins is not well characterized in SN-GPC. We examined three SN-GPCs by immunohistochemistry and CTNNB1 mutation analysis. All cases expressed nuclear β-catenin. We identified CTNNB1 exon 3 mutations in two analyzable cases. Lymphoid enhancer-binding factor 1 (LEF1), a protein downstream from β-catenin, was also expressed in all cases. Our results further characterized the activation of the Wnt signaling pathway caused by CTNNB1 exon 3 mutation and suggest the utility of LEF1 immunohistochemistry in the differential diagnosis of SN-GPC.

Glomangiopericytoma of the Spinal Cord

Glomangiopericytoma, also referred to as a hemangiopericytoma-like tumor or sinonasal type hemangiopericytoma, is a rare tumor of the nasal cavity and paranasal sinus that has never been reported in the spinal cord. Here, we report a case of a 47-year-old man who developed glomangiopericytoma in the thoracic spine. This lesion showed a heterogeneous high signal intensity compared to the spinal cord on a T2-weighted image and an easily enhanced isointense signal on a T1-weighted image.

Nuclear β-Catenin Expression is Frequent in Sinonasal Hemangiopericytoma and Its Mimics

Sinonasal hemangiopericytoma (HPC) is a tumor showing pericytic myoid differentiation and which arises in the nasal cavity and paranasal sinuses. CTNNB1 mutations appear to be a consistent aberration in sinonasal HPC, and nuclear expression of β-catenin has been reported. Our aim was to evaluate the frequency of β-catenin expression in sinonasal HPC and its histologic mimics in the upper aerodigestive tract. Cases were retrieved from the surgical pathology and consultation files. Immunohistochemical staining for β-catenin was performed on 50 soft tissue tumors arising in the sinonasal tract or oral cavity, and nuclear staining was recorded semiquantitatively by extent and intensity. Nuclear reactivity for β-catenin was present in 19/20 cases of sinonasal HPC; 17 showed moderate-to-strong multifocal or diffuse staining, and 2 had moderate focal nuclear reactivity. All solitary fibrous tumors (SFT) (10/10) showed focal-to-multifocal nuclear staining, varying from weak to strong in intensity. Most cases of synovial sarcoma (9/10) showed nuclear β-catenin expression in the spindle cell component, ranging from focal-weak to strong-multifocal. No cases of myopericytoma (0/10) showed any nuclear β-catenin expression. β-catenin expression is prevalent in sinonasal HPC, but is also frequent in SFT and synovial sarcoma. Our findings indicate that β-catenin is not a useful diagnostic tool in the evaluation of spindle cell tumors with a prominent hemangiopericytoma-like vasculature in the sinonasal tract and oral cavity, and that definitive diagnosis relies on the use of a broader immunohistochemical panel.

Biphenotypic sinonasal sarcoma: an expanded immunoprofile including consistent nuclear β-catenin positivity and absence of SOX10 expression

Biphenotypic sinonasal sarcoma (BSNS) is a recently recognized low-grade sarcoma that exhibits both neural and myogenic differentiation. This unique dual phenotype stems from recurrent rearrangements in PAX3, a transcription factor that promotes commitment along both lineages. While identification of PAX3 rearrangements by fluorescence in situ hybridization (FISH) can confirm a BSNS diagnosis, this assay is not widely available. This study evaluates whether an expanded immunohistochemical panel can facilitate recognition of BSNS without molecular analysis. Eleven cases of BSNS were identified from the surgical pathology archives of two academic medical centers. In 8 cases, the diagnosis was confirmed by FISH using custom probes for PAX3. In 3 cases, FISH failed but histologic and immunophenotypic findings were diagnostic for BSNS. All 11 BSNS (100%) were at least focally positive for S100 as well as calponin and/or smooth muscle actin. In addition, 10 (91%) of 11 expressed nuclear β-catenin, 8 (80%) of 10 expressed factor XIIIa, 4 (36%) of 11 expressed desmin, and 3 (30%) of 10 expressed myogenin. All 11 tumors were negative for SOX10. While no single marker resolves immunohistochemical overlap between BSNS and its histologic mimickers such as nerve sheath tumors, an extended immunohistochemical panel that includes β-catenin and SOX10 helps to support the diagnosis of BSNS without the need for gene rearrangement studies.

Glomangiopericytoma simulating an intracavernous meningioma

Background:

Glomangiopericytoma is an uncommonly encountered tumor of the nose and paranasal sinuses, accounting for <0.5% of all sinonasal tumors. Extension of these lesions to the anterior or middle cranial fossa is rare. When this occurs, diagnosing glomangiopericytoma is extremely challenging, as it is often confused with other anterior skull base tumors.

Case Description:

We report a case of a giant glomangiopericytoma localizing into the cavernous sinus in a 48-year-old female who presented with mild left-sided ptosis for 48 months. The lesion simulated an intracavernous meningioma on preoperative imaging. An expanded endoscopic endonasal approach was used to debulk the portion of the lesion in the medial compartment of the cavernous sinus. Postoperatively, the patient's ptosis resolved completely, and no new deficits were sustained.

Conclusion:

This is the only case of glomangiopericytoma localizing solely to the cavernous sinus reported to date.

Nasal Cavity and Paranasal Sinuses

The nasal cavity and paranasal sinuses occupy the top of the upper respiratory tract and form pneumatic spaces connected with the atmosphere. They are located immediately beneath the base of the cranium, where crucial vital structures are harbored. From this region, very much exposed to airborne agents, arise some of the more complex and rare benign and malignant lesions seen in humans, whose difficulties in interpretation make this remarkable territory one of the most challenging in the practice of surgical pathology.

Contents of this chapter cover inflammations and infections, polyps and pseudotumors, fungal and midfacial destructive granulomatous lesions, as well as benign, borderline, and malignant neoplasms. Among the neoplasms, emphasis is made on those entities characteristic or even unique for the sinonasal region, such as Schneiderian papillomas, glomangiopericytoma, intestinal- and non-intestinal-type adenocarcinomas, olfactory neuroblastoma, nasal-type NK-/T-cell lymphoma, and teratocarcinosarcoma. Moreover, recently recognized entities involving this territory, i.e., HPV-related non-keratinizing carcinoma, NUT carcinoma, and SMARCB1-deficient basaloid carcinoma, are also discussed in the light of their specific molecular findings. Furthermore, the text is accompanied by numerous classical and recent references, several tables, and 100 illustrations.

Endoscopic Resection of Sinonasal Hemangiopericytoma following Preoperative Embolisation: A Case Report and Literature Review

Objectives. Hemangiopericytoma is a rare tumor entity deriving from pericytes. Less than 5% of hemangiopericytoma occur in the nasal cavity and are characterised by a rather benign nature with low tendency of metastasis. However, as the recurrence rate in the literature ranges from 9.5% to 50%—depending on the length of followup—a radical surgical resection is considered as the gold-standard treatment. Only a few years ago, a wide external approach, usually via lateral rhinotomy or Caldwell-Luc, was performed. Endoscopic techniques were regarded as appropriate for small low-vascularised tumors only. Methods. We present the case of a 64-year-old patient with an extended sinonasal hemangiopericytoma, who was successfully treated by an endoscopic controlled endonasal tumor resection after embolisation with Onyx. Further, to support the new treatment option, we review the literature concerning all features of sinonasal hemangiopericytomas and their therapeutical management. Results/Conclusion. Onyx, which has not been described in the context of hemangiopericytoma yet, is a very effective embolic agent for a preoperative embolisation of sinonasal hemangiopericytoma allowing a safe endoscopic surgery.

Management of sinonasal hemangiopericytomas: a systematic review

BACKGROUND

Hemangiopericytomas are typically found in soft-tissue, but only rarely found in the sinonasal tract. Sinonasal hemangiopericytomas have been reported mostly through case studies, and optimal treatment is considered surgical excision. Classically, open surgical methods of tumor extirpation have been considered standard of care. With the wider use of endoscopic methods, an updated systematic review in terms of treatment is warranted.

METHODS

Cases were identified using a MEDLINE and PubMed search. Relevant studies were identified, and data was extracted regarding patient demographics, presenting symptoms, tumor characteristics, treatment, and outcomes.

RESULTS

A total of 128 cases were collected from 56 articles, consisting of case reports and series. The most common presenting symptoms were epistaxis, nasal obstruction, and facial pain/swelling/pressure. Computed tomography (CT) and X-ray were the most common modes of imaging during diagnosis and operative planning. The tumor often occupied multiple locations in the sinonasal tract at initial presentation. Surgical resection was the mainstay of treatment in 126 of the 128 cases (98.4%), either through open resection or endoscopic techniques. Surgical removal resulted in no recurrence in 79.7% of the cases. The use of endoscopic techniques increased significantly in the past decade. This review found no significant difference in terms of recurrence between endoscopic and open treatment groups, age, gender, and unilocality vs multilocality of tumor.

CONCLUSION

Surgical management remains the mainstay of treatment for hemangiopericytomas. Endoscopic resection of these lesions has increased over the last few decades and has become a safe, viable, and reasonable alternative to open resection.

Glomangiopericytoma (sinonasal-type haemangiopericytoma)

Background:

Glomangiopericytoma is a rare sinonasal tumour of perivascular myoid phenotype, which accounts for less than 1 per cent of all sinonasal tumours.

Objective:

Discussion of the clinical presentation, histopathological features and advances in the management of sinonasal and skull base glomangiopericytoma.

Case report:

A 32-year-old woman presented with worsening nasal obstruction, anosmia, severe frontal headaches and right-sided proptosis. Radiographic and endoscopic examination revealed a right-sided, vascular mass involving the nasal cavity, paranasal sinuses and anterior skull base. Histopathological features were consistent with a glomangiopericytoma. Complete endoscopic resection with free margins was achieved.

Conclusion:

Glomangiopericytomas are rare, vascular, sinonasal tumours. Successful management depends on complete resection, traditionally achieved via an open approach. However, recent advances in endoscopic surgical approaches have enabled complete endoscopic resection of these tumours, minimising morbidity and facilitating subsequent surveillance of the operative site.

Systematic review of treatment and prognosis of sinonasal hemangiopericytoma

BACKGROUND

This study was undertaken to determine the recurrence rate for open and endoscopic surgery and the clinical prognosis of this sinonasal tumor.

METHODS

A systematic review of individual cases of sinonasal hemangiopericytoma was performed. A total of 97 articles were included in the study and reviewed to extract the relevant information about each case.

RESULTS

In all, 194 cases of sinonasal hemangiopericytoma were identified. There were 53 recurrences (27.3%), 6 tumor-related deaths (3.1%), and 4 cases of metastases (2.1%). There was no significant difference between rate of recurrence for endoscopic or open resection (p = .06). Incomplete excision was the most important predictor of recurrence (odds ratio = 11.50, 95% confidence interval 3.76-36.82, p < .001). Radiotherapy may be advantageous in cases of incomplete surgical resection (p = .03).

CONCLUSIONS

Complete excision is essential to minimize tumor recurrence and radiotherapy may decrease the rate of recurrence in the case of incomplete resection. Current evidence does not suggest that open resection is superior to endoscopic resection.

Striking pathology gold: a singular experience with daily reverberations: sinonasal hemangiopericytoma (glomangiopericytoma) and oncogenic osteomalacia

Sinonasal hemangiopericytoma-like tumors(SNHPC)(glomangiopericytomas)were originally conceived as histologically similar to, but biologically distinct from, their soft tissue counterparts. Re-evaluation of "hemangiopericytiomas" has determined that SNHPC (glomangiopericytomas) represent bona-fide pericyte-derived tumors, whereas most soft tissue neoplasms previously designated as hemangiopericytomas represent cellular variants of solitary fibrous tumors or other lesions with a hemangiopericytomalike growth pattern. We present an interesting case of a woman with SNHPC (glomangiopericytomas) causing oncogenic osteomalacia, and discuss the recent advances in our understanding of phosphaturic mesenchymal tumors. This particular case is an example of "Striking Pathology Gold"-a situation where the pathologist actively guides the diagnostic process, and witnesses its repercussions. "Striking Pathology Gold" may be a rare event in one's career. However it serves to remind us of our place in the world as physicians. Working behind the scenes, we quietly change the course of countless individual destinies for the better.

FDG PET/CT findings of a glomangiopericytoma

Glomangiopericytoma (GPC) is a rare vascular neoplasm that arises almost exclusively from the nasal cavity or paranasal sinuses. GPC is also called sinonasal-type hemangiopericytoma, although current nomenclature, as well as classification in a group with myopericytomas, better emphasizes the relatively indolent behavior of this tumor. The authors present the FDG PET/CT findings of GPC in a 53-year-old with symptoms of nasal congestion and facial pressure. CT and MRI showed a nasal mass to extend along the sphenoid ridge from the posterior nasal cavity into the posterior nasopharynx. PET showed the mass to have uniformly low-grade FDG hypermetabolism. Pathologic examination of the surgical specimen showed classic features of GPC.

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.

Endoscopic, endonasal management of sinonasal haemangiopericytoma: 12-year experience

AIM

To report our experience with endoscopic, endonasal management of sinonasal haemangiopericytoma.

MATERIALS AND METHODS

Retrospective review of the medical records of 10 patients undergoing endoscopic, endonasal surgery for sinonasal haemangiopericytoma of the nose and paranasal sinuses, between 1997 and 2008.

RESULTS

Five men and five women were included. Their mean age at surgery was 59 years. All patients underwent endoscopic, endonasal resection of their tumour. Major post-operative complications were encountered in only one patient (stroke). Local recurrence was diagnosed in only one patient (10 per cent), who subsequently underwent a combined resection (endoscopic and external) with orbital exenteration.

CONCLUSIONS

Sinonasal haemangiopericytomas are rare tumours that are usually benign. The mainstay of treatment is wide surgical excision with free resection margins. Nowadays, the great majority of patients can be treated using a purely endoscopic, endonasal approach.

[Sinonasal hemangiopericytomas]

OBJECTIVES

The aim of this study was to report on the clinical, radiological and histological characteristics of hemangiopericytomas, and to discuss our experience with their treatment.

MATERIAL AND METHODS

The authors reexamined two recent cases of patients presenting with sinonasal hemangiopericytomas (semiology, CT and MRI results, treatment and follow-up).

RESULTS AND DISCUSSION

There was substantial variability of hemangiopericytoma presentation depending on location. Hemangiopericytomas of the nose and paranasal sinuses are considered a distinct entity with a good prognosis. Treatment is based on endoscopic sinus surgery. The histological approach requires the use of immunohistochemistry. Recurrences vary in the literature depending on the initial resection quality. Metastases are rare.

Intranasal myopericytoma. A tumour with perivascular myoid differentiation: the changing nomenclature for haemangiopericytoma

We present a case report of a patient who developed a sinonasal myopericytoma treated by surgical excision through a lateral rhinotomy. Some aggressive features on pre-operative computed tomography scanning and the complexity of recent changes in the histological nomenclature for these tumours led to consideration of adjuvant therapy. The close histological relationship between myopericytoma, myofibromatosis, solitary myofibroma and infantile haemangiopericytoma is discussed. This group of lesions constitute a single morphological spectrum with differentiation towards perivascular myoid cells (pericytes). Currently myopericytoma is the most appropriate and accepted term embracing all these entities. A review of the literature has been reassuring in identifying these tumours as benign but with a reasonably high rate of local recurrence (17 per cent). The treatment of choice is surgical excision with further excisions for local recurrence.

Glomangiopericytoma of the pterygomandibular space: an unusual case

We describe a case of glomangiopericytoma located in the pterygo-mandibular space, a rare anatomical region for this neoplasm to develop. The lesion is classified as a separate variant from the classic haemangiopericytoma, which is characterised by more aggressive biological behaviour.

Solitary fibrous tumour and haemangiopericytoma: evolution of a concept

Haemangiopericytoma (HPC) was described in 1942 by Stout and Murray as a distinctive soft tissue neoplasm, presumably of pericytic origin, exhibiting a characteristic well-developed "staghorn" branching vascular pattern. Over the years, it appeared that this growth pattern was a non-specific one, shared by numerous, unrelated benign and malignant lesions, and that HPC was better considered as a diagnosis of exclusion. Three categories of lesion may now be individualized within the heterogeneous group of HPC-like neoplasms. The first category corresponds to those non-HPC neoplasms that occasionally display HPC-like features (e.g. synovial sarcoma). Lesions belonging to the second category show clear evidence of myoid/pericytic differentiation and correspond to true HPCs. They generally show a benign clinical course, and include glomangiopericytoma/myopericytoma, infantile myofibromatosis (previously called infantile HPC), and a subset of sinonasal HPCs. The third category is the solitary fibrous tumour (SFT) lesional group, which includes fibrous-to-cellular SFTs, and related lesions such as giant cell angiofibromas and lipomatous HPCs. In practice, any HPC-like lesion can be allocated to one of these categories, leaving the ill-defined "haemangiopericytoma" category empty.

D2-40 staining in sinonasal-type hemangiopericytoma--further evidence of distinction from conventional hemangiopericytoma and solitary fibrous tumor

D2-40 is a monoclonal antibody, which reacts with a fixative-resistant epitope of lymphatic endothelium. Sinonasal-type hemangiopericytoma (SHP) and tumors of the (conventional) hemangiopericytoma/solitary fibrous tumor family (HP/SFT) are characterized by prominent vasculature. However, data concerning D2-40 labeling of these tumors are very sparse. In the present study, we investigated D2-40 staining in tissue specimens of 17 patients with SHP (male to female ratio of 2.4:1, median age of 63 years) and compared the immunolabeling with 20 cases of HP/SFT, including three SFT cases from nasal mucosa. D2-40 was detected in vascular channels of all SHP patients examined. By contrast, all cases of HP/SFT did not reveal any vascular channel being positive for D2-40, neither in the nasal cases nor in the remaining patients. This study presented for the first time data on D2-40 labeling in a series of SHP, HP/SFT, and supports the distinction of SHP from HP/SFT.

Sinonasal hemangiopericytoma-like tumor with true pericytic myoid differentiation: a clinicopathologic and immunohistochemical study of five cases

BACKGROUND

Sinonasal hemangiopericytoma-like tumor (SHPCL) is an uncommon vascular tumor that is sometimes difficult to diagnose.

METHOD

We report five cases arising from the nasal cavity. The tumors were subdivided into two types, prototype and soft tissue type, by the difference in histologic features.

RESULTS

The prototype, made up of three tumors, is characterized by uniform, spindle-shaped myoid cells that have eosinophilic cytoplasm and uniform nuclei and lay down in an orderly fashion. The soft tissue type, made up of two tumors, is similar to the hemangiopericytoma of soft tissue. Immunohistochemically, the tumors were positive for vimentin (100%), smooth muscle actin (80%), muscle-specific actin (100%), fibroblast growth factor-2 (100%), and vascular endothelial growth factor (100%). All were negative for cytokeratin, desmin, CD34, and factor VIII-related antigen. These histopathologic features suggest myoid differentiation and angiogenic activity of the tumors. All the tumors were treated with wide surgical excision. Only one case of soft tissue-type tumor with active mitoses received additional postoperative radiotherapy. No recurrence was found during 13 to 120 months of follow-up.

CONCLUSIONS

Our data suggest that SHPCL with convincing myoid differentiation may have a more favorable clinical course than its soft tissue counterpart.

[Sinonasal hemangiopericytoma]

Hemangiopericytomas are rare perivascular tumors. The nasal cavity and paranasal sinuses are most often involved in the head and neck region. A case of hemangiopericytoma in a 63 year old patient is presented. The initial symptom was recurrent bleeding from the nose. The patient had a history of radiotherapy for a pituitary adenoma 30 years previously. Computed tomography and magnetic resonance imaging showed a polypoid opacification of the ethmoid, sphenoid and basal aspects of the frontal sinus on the right side. Histological diagnosis was obtained from nasal biopsy. Preoperatively, arteriography and tumor embolisation were performed. The tumor was completely excised using a combined endonasal and external approach as an osteoplastic revision of the frontal sinus via bicoronal incision. There was no recurrence at follow-up 1 year later.

Low-grade sarcomas with CD34-positive fibroblasts and low-grade myofibroblastic sarcomas

A subset of low-grade fibrosarcomas is composed of CD34-positive spindle cells. These include dermatofibrosarcoma, its morphologic variants, and its associated fibrosarcoma, solitary fibrous tumor, hemangiopericytoma and their malignant counterparts, and some cases of myxoinflammatory fibroblastic sarcoma. Dermatofibrosarcoma and related lesions are characterized by a t(17;22)(q22;q13) rearrangement resulting in fusion of the genes COL1A (17q21-22) and PDGFB1 (22q13). Solitary fibrous tumor displays varying cellularity and fibrosis and a peripheral hemangiopericytomatous pattern; most tumors formerly called hemangiopericytoma are now subsumed into the category of solitary fibrous tumor, although a few strictly defined examples are recognized; however, these are probably not composed of pericytes. Myofibroblastic malignancies are best identified by electron microscopy, with which varying degrees of differentiation, including the presence of fibronexus junctions, can be identified. Low-grade sarcomas showing myofibroblastic differentiation include myofibrosarcomas and inflammatory myofibroblastic tumors. Myofibrosarcomas are spindle cell neoplasms that occur in children or adults in the head and neck, trunk, and extremities as infiltrative neoplasms and that display a fascicular or fasciitis-like pattern with focal nuclear atypia and variable expression of myoid antigens. These sarcomas are prone to recurrence and a small number metastasize. Inflammatory myofibroblastic tumor (synonymous with inflammatory fibrosarcoma) is a neoplasm arising predominantly in childhood, and frequently in intraabdominal locations. It has spindle cells in fascicular, fasciitis-like and sclerosing patterns, with heavy chronic inflammation including abundant plasma cells. Many IMT have clonal chromosomal abnormalities involving 2p22-24, and fusion of the ALK gene with tropomyosin 3 (TPM3-ALK) or tropomyosin 4 (TPM4-ALK) is found in a subset.

Primary glomangioma of the liver: a case report and review of the literature

Glomangiomas are a subset of glomus tumors that have a rich vascular network. Although a majority of the glomus tumors occur in the skin of the hand, they have also been reported in the deep soft tissue, bone, lungs, and gastrointestinal tract, especially the stomach. To our knowledge, only one such case has previously been reported primarily occurring in the liver. We report a case of a glomangioma primarily arising in the liver of a 57-year-old man who presented with right flank pain of several months' duration. A 3.0-cm hepatic mass was excised and consisted of numerous, small-to-medium branched vessels with the stroma containing small, round, regular cells with sharply outlined round-to-oval nuclei. Immunostains showed the tumor cells to be diffusely positive for vimentin and smooth muscle actin and to be focally positive for calponin. Collagen IV stained the pericellular matrix. The immunostain for CD34 highlighted the vascular network as well as outlined the tumor cells in many areas. Coexpression of actin and CD34 in glomus tumors, although unusual, has recently been reported in the literature. Despite its bland histology, the large tumor size and deep visceral location were suggestive of aggressive behavior; thus, a close clinical follow-up was recommended. The patient had an unremarkable postoperative course and has no evidence of metastatic disease 12 months after the procedure. An accurate diagnosis and an understanding the biology of this rare disease, especially in an unusual location, are crucial to its management.

Intranasal pericytic tumors (glomus tumor and sinonasal hemangiopericytoma-like tumor): report of two cases with review of the literature

An intranasal glomus tumor and a sinonasal hemangiopericytoma-like tumor are reported. Both patients were elderly women suffering from nasal bleeding, and presented with a polypoid mass arising in the nasal septum. Microscopically, the glomus tumor displayed a proliferation of uniform rounded or cuboidal epithelioid cells arranged in sheets and interrupted by a rich vasculature with a characteristic configuration mimicking the normal glomus bodies, while the sinonasal hemangiopericytoma-like tumor featured a perivascular proliferation of spindle- to oval-shaped cells that were arranged in short fascicles. Both tumors shared immunohistochemical features supporting their myoid differentiation by the expression of vimentin, alpha-smooth muscle actin and muscle-specific actin, albeit with no immunoreaction to desmin. Both the intranasal glomus tumor and sinonasal hemangiopericytoma-like tumor are characterized by a perivascular growth pattern and myoid differentiation, having a close relation to the 'perivascular myomas', which was recently designated.