Myopericytoma in patients with AIDS: a new class of Epstein-Barr virus-associated tumor

Renal myopericytoma: A case report with a literature review

Myopericytoma is a rare soft tissue tumor characterized by differentiation into perivascular muscle-like cells or perimuscular cells. This tumor primarily affects adults and is uncommon in children. It is predominantly found in the subcutaneous soft tissues of the distal limbs, and cases originating in the kidney are exceedingly rare. In this report, we present a case of a patient with renal myopericytoma admitted to our hospital. We also summarize the diagnostic and therapeutic features by reviewing relevant domestic and international literature.

Myopericytoma of the Right Middle Finger: A Case Report of an Uncommon Perivascular Neoplasm

This report describes the case of a 29-year-old male who presented with painless swelling on the volar aspect of his right middle finger. The initial clinical impression was consistent with an epidermal inclusion cyst. A plain radiograph of the lesion revealed a circumscribed superficial nodular soft tissue mass confined to the dermis of the affected finger. Following surgical excision and subsequent histopathologic examination, the lesion was ultimately identified as a myopericytoma (MPC). The occurrence of MPCs in the finger is uncommon; thus, a high level of suspicion is required to consider it as one of the differential diagnoses for painless nodules in this anatomical location. Surgery serves as the primary method for treatment, and histopathologic evaluation plays a crucial role in confirming the diagnosis and ruling out malignancy.

Pediatric upper lip myopericytoma: a case report and comprehensive review

BACKGROUND

Myopericytoma is a rare spindle cell tumor of mesenchymal origin, typically benign, characterized by concentric proliferation of tumor cells around blood vessels within subcutaneous tissue. It primarily occurs in middle-aged adults and is often located in distal extremities, although cases have been reported in proximal extremities and head-neck regions. However, occurrences within the oral cavity are exceedingly rare. To date, literature reviews have identified only two cases in children under 10 years old and reported only five cases of myopericytoma occurring in the lip region. We provide a comprehensive review and analysis of all documented cases to better understand this condition.

CASE PRESENTATION

A 7-year-old girl presented to oral and maxillofacial surgery with the discovery of a painless mass on the inner aspect of the upper lip. The diagnosis of myopericytoma was confirmed by histological examination (HE staining), alcian blue staining, and immunohistochemistry.

CONCLUSIONS

Following surgical excision, there were no signs of recurrence at a 3-month follow-up. The pathological diagnosis of myopericytoma is quite challenging, and immunohistochemical testing is necessary.

Primary hepatic myopericytoma coexisting with multiple cystic hepatic lesions: a case report

BACKGROUND

Hepatic myopericytoma (MPC) is an extremely rare pathological entity in the liver. Conversely, cystic hepatic lesions are a group of heterogeneous lesions encountered commonly in daily practice. Here, we report a unique case of the coexistence of primary hepatic MPC and multiple cystic hepatic lesions along with our perceptions on its diagnosis and treatment.

CASE PRESENTATION

A 56-year-old female patient was found to have a left liver mass during a routine physical examination. Computer tomography (CT) and magnetic resonance imaging (MRI) confirmed the existence of a left hepatic neoplasm along with multiple hepatic cysts but could not exclude the possible malignant nature of the neoplasm. Computer tomography (CT) also identified an enlarged mediastinal lymph node with a maximum diameter of 4.3 cm, which further underwent core needle biopsy under CT guidance. A histopathological examination was performed to rule out malignancy. Afterwards, the patient underwent left hemihepatectomy to resect a solid tumor of 5.5 cm × 5 cm × 4.7 cm with multiple cystic lesions which were histopathologically examined to establish the diagnosis of myopericytoma with hepatic cysts. Postoperatively, the patient recovered from the surgery quickly without significant adverse events and was not found to have a reoccurrence of the primary pathological entity.

CONCLUSIONS

This is the first reported case of a patient with the co-existence of primary hepatic myopericytoma and multiple cystic hepatic lesions undergoing surgical treatment with eventual recovery.

Rare Case of Intravascular Myopericytoma-Imaging Characteristics and Review of the Literature

Myopericytoma is a rare vessel wall tumor, a subtype of hemangiopericytoma that usually develops subcutaneously. Intravascular myopericytoma is a rarer subtype, with only few cases reported in the literature and even fewer with imaging modalities included. We report the case of a 36-year-old man who was referred to our institution with a painless, palpable mass in the right arm and was evaluated with MRI, grey-scale and Doppler-mode ultrasound. Tumor histopathology and imaging characteristics are presented together with the role that each imaging modality played in the management of the patient.

Myopericytoma: A Review of Twenty-Three Cases Over Twelve Years and a Case Report of a Rare Neoplasm

Myopericytoma is a rare soft tissue tumor with a predilection for the distal extremities. It is commonly found in the skin and subcutaneous tissues and usually takes a benign course. Current knowledge is limited to isolated case series and reports; hence, this study aims to report our tertiary institution's experience with this uncommon entity. A review of our institution's pathology records for cases of myopericytoma was performed. From January 2009 to September 2020, 23 cases of myopericytoma were identified and their clinicopathologic features were reported. A unique case of myopericytoma of the ankle from the series was also highlighted as a case report. Among the 22 cutaneous cases, 18 were in the extremities and 4 in the head and neck. One patient had an intracranial lesion. Most patients developed asymptomatic nodules (72.2%), but 1 patient had a locally aggressive tumor on presentation. None recurred despite marginal excision in some patients (80.0%). In conclusion, pathologists and surgeons who encounter this rare neoplasm can reassure patients of its benign tendency.

Epstein-Barr virus-associated intracranial myopericytoma in a child: case report and review of literature

BACKGROUND

Myopericytomas are benign soft tissue tumors which are rarely found as intracranial masses.

METHODS

A review of SCOPUS and PubMed databases for case reports and case series was done for patients with intracranial myopericytomas. Data on demographics, clinical features, imaging, surgical management employed, and outcomes were collected.

RESULTS

We found a total of 9 cases in the literature and we describe an additional case from our own experience. The mean age at presentation was 50.1 years (32-64 years), with a female predominance. Most tumors were in the posterior fossa and were multifocal in AIDS patients. The most common clinical manifestations were visual disturbances, headaches, and vomiting. An association with EBV was reported in two cases and was also found in our own case. Gross total excision and even subtotal excision were definitive therapies with no recurrences reported with a mean follow-up of 22.7 months. Our case is the first EBV-associated intracranial myopericytoma in a child.

CONCLUSION

Intracranial myopericytomas are rare; some have an association with EBV and immunodeficient states. Surgery is the only necessary treatment and outcomes are generally favorable for these benign neoplasms.

Ankle Myopericytoma: A Rare Case Report and Cytogenetic Study

Myopericytoma (MPC) is an uncommon benign neoplasm of the skin and soft tissues belonging to a spectrum of tumors that are histologically recognized by their distinctive perivascular myoid cell differentiation. These distinct tumors are more prevalent among middle-aged males, and they arise more frequently in the subcutaneous tissue of the four extremities. In this paper, myopericytoma is reported in a 59-year-old Saudi male, presented with a painless small cyst involving the left ankle suspected clinically to be a ganglion cyst. Following surgical excision of the cyst, the diagnosis of myopericytoma was made based on the histopathological pattern of the disease. This paper focuses on the clinical and histopathological findings of myopericytoma and emphasizes the importance of immunohistochemistry as well as molecular testing in reaching the final diagnosis.

Fast growing myopericytoma of the hand: Case report and literature review

Introduction and importance

Myopericytoma (MPC) is a rare benign soft tissue neoplasm that arises from perivascular smooth muscle-like myoid cells that share features of both glomus and smooth muscle cells. It usually slow growing solitary tumor that might mimic aggressive sarcoma.

Case presentation

45 years old male, with unremarkable medical history, presented with fast growing mass on the left 1st webspace that was noticed 6 months prior to presentation. Investigations with US and MRI showed highly vascular solid mass that was worrisome for malignant lesion. Surgical excision was done and histopathology confirmed the diagnosis of myopericytoma.

Clinical discussion

MPC is a rare perivascular neoplasm that’s reported mainly in the extremities with lower limbs are most affected sites. Usually it presents as solid painless slowly growing mass. However, Multiple papers reported different rare presentations like multiple, painful and some with malignant transformation.

Conclusion

MPC is a benign tumor that might mimic aggressive sarcoma. Such cases should be approached with high suspicion and proper investigation and management should be followed promptly.

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Myopericytoma (MPC) is a rare benign soft tissue neoplasm.

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It usually slow growing solitary tumor that might mimic aggressive sarcoma.

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It occurs mainly in the extremities with lower limbs are most affected sites.

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High suspicion and proper investigation and management to achieve proper diagnosis

Oral myopericytoma: a rare pediatric case report and a review of the literature

Background

Myopericytoma is a rare mesenchymal neoplasm with perivascular myoid differentiation that arises most commonly in middle adulthood. The lesion generally involves the subcutaneous tissue of distal extremities. Myopericytoma of the oral cavity is extremely rare. Herein we report a case of oral myopericytoma in a pediatric patient, who was treated via a conservative approach with a follow up of 8 years. The case is followed by a literature review. To our knowledge this is the first documented case of oral myopericytoma affecting a patient of such a young age.

Case presentation

A 6 years old boy was referred to the maxillofacial surgery department for the evaluation of a solitary growth of the right maxillary buccal and palatal gingiva. Histology and immunohistochemistry confirmed the diagnosis of myopericytoma.

Conclusions

Our patient was treated by local excision with no recurrence in 8 years of follow up. Conservative approach should be considered for the treatment oral myopericytoma especially in young patients in tooth bearing areas.

Orbital myopericytoma: an unusual tumor in an unusual location

A 71-year-old male with a 4-month history of bulging, tearing, and redness in the right eye presented with vision loss, proptosis, conjunctival hyperemia, and chemosis. Magnetic resonance imaging showed a right intraconal solid mass with extraconal extension, hyper-intense in T2 sequences with heterogeneous contrast enhancement. Complete excision of the mass was performed through a lateral orbitotomy. Histological analysis revealed a neoplasm with high vessel density, solid growth of oval cells, a concentric proliferation of the wall of small vessels, and a weak and patchy positivity for smooth muscle actin. These findings were consistent with the diagnosis of myopericytoma. After surgery, visual acuity improved in the affected eye and after 18 months of follow-up there have been no signs of recurrence.

Radiopathological correlations of myopericytomas of the hand: emphasis on the MRI perivascular pushing growth pattern

Myopericytomas are exceedingly rare soft-tissue tumors with less than 10 cases including radiological depictions. We report three new cases of benign myopericytomas located in the soft-tissues of the hand in adult patients. A pre-treatment MRI was available for all patients and systematically evidenced well-defined, lobulated tumors closely related to the superficial palmar vascular arch and/or digital vessels with a perivascular pushing growth pattern that correlated with pathological findings. Though rare, this small case series show that myopericytomas display recurrent imaging features that could support their radiological diagnosis.

Clinical and pathologic analysis of myopericytoma in the oral and maxillofacial region

OBJECTIVE

The aim of this study was to analyze myopericytoma in the oral and maxillofacial region in terms of clinical appearance, diagnosis, treatment, and outcomes.

STUDY DESIGN

Data on 5 new patients with myopericytoma in the oral and maxillofacial region treated at our department were collected and analyzed.

RESULTS

There were 2 males and 3 females (age range 10-62 years; mean age 43.8 years). All of the 5 patients presented with masses showing benign biologic behavior. Imaging examinations with use of computed tomography or magnetic resonance imaging showed heterogeneous regions with internal contrast-enhancement or cystic change in 3 cases. All of the patients underwent surgery. Histologic examination showed a broad morphologic spectrum characterized by concentric and perivascular growth of ovoid, plump spindled, and/or round myoid tumor cells. Immunohistochemical examination showed positive staining for vimentin and smooth muscle actin, and negative for CD34 and desmin. During the follow-up period (8-56 months), there was no tumor recurrence.

CONCLUSIONS

Myopericytoma in the oral and maxillofacial region always exhibits benign biologic behavior and a heterogeneous region with internal contrast-enhancement or cystic change on imaging examinations. Surgery is the first choice of treatment and results in good clinical outcomes.

Myopericytoma at the Craniocervical Junction: Clinicopathological Report and Review of a Rare Perivascular Neoplasm

BACKGROUND AND IMPORTANCE

Myopericytoma is an emerging class of neoplasm originating from the perivascular myoid cellular environment, previously classified as a variant of hemangiopericytoma. Most reported myopericytomas are found in soft tissues of the extremities; however, infrequent cases are described involving the central nervous system. Intracranial myopericytoma remains rare. Here, we describe the first report of myopericytoma occurring at the cervicomedullary junction in close proximity to the vertebral artery, mimicking a vascular lesion.

CLINICAL PRESENTATION

A 64-yr-old woman presented with radiating neck pain. Magnetic resonance imaging revealed a well-circumscribed enhancing lesion adjacent to the vertebral artery-accessory nerve complex. She underwent a far lateral craniotomy and cervical laminectomy to obtain proximal vertebral artery control and adequate exposure of the lesion, which appeared most consistent with neoplasm at surgery. Histopathology revealed a grade I myopericytoma. A gross total resection was achieved, and the patient has no evidence of recurrence 3 yr after surgery.

CONCLUSION

Tumors of perivascular origin include hemangiopericytoma, glomus tumor, myofibroma, and myopericytoma and are uncommon lesions intracranially. Consideration of and distinction among these perivascular tumors is critically important, as they each have distinct clinical behaviors and management. Myopericytoma can mimic other neoplastic and cerebrovascular pathologies, but it most commonly has a benign course and can be surgically cured if a gross total resection can be achieved. Rarer myopericytoma variants that adopt a more malignant course have been described, and ongoing molecular studies may identify mutations or activated signaling pathways that can be targeted to offer chemotherapeutic options in the future.

Intracranial myopericytoma: a tumour in a rare location

A 49-year-old female with history of headache, nausea and vomiting with some weeks of evolution, without neurological symptoms. Radiology revealed an expansive lesion near the inferior vermix and cerebellar tonsils, with heterogeneous gadolinium uptake and mass effect on the fourth ventricle, representing a probable extraventricular origin for the lesion. Pathological examination showed a proliferation of oval/spindle cell proliferation with eosinophil cytoplasm and small and monotonous nuclei, without mitoses. The cells had a concentric growth, surrounding thin-walled blood vessels with foci of stromal myxoid degeneration and whorled pattern. The vessels had a haemangiopericytoma pattern and were lined by non-atypical endothelial cells. The tumorous cells expressed vimentin, alpha-smooth actin and heavy-chain caldesmon and were negative for epithelial membrane antigen, protein S100, HMB45, CD34, calponin and desmin, thus providing the final diagnosis of intracranial myopericytoma.

Primary malignant myopericytoma with cancer cachexia: Report of the first case and review of literature

RATIONALE

Malignant myopericytoma is extremely rare, with a few cases described in the English literature.

PATIENT CONCERNS

This novel study aimed to report a case of malignant myopericytoma with cancer cachexia arising in the left armpit. Also, it presented a review of the English literature regarding primary malignant myopericytoma, aiming to clarify the clinical features and potentially curative treatment. A 56-year-old male presented with an ulcerated and smelly mass involving her left armpit. The patient had obvious symptoms of cancer cachexia, including emaciation, anemia, and lower extremity edema.

DIAGNOSES

Computer tomography (CT) scan demonstrated a mass in the left armpit, with no evidence of metastasis according to the chest CT, abdominal ultrasound, and emission CT. The patient underwent a core biopsy of the mass, and a diagnosis of malignant myopericytoma was rendered.

INTERVENTIONS

He received 2 standard courses of theprubicin combined with ifosfamide chemotherapy regimen with no tumor response. Then, he subsequently underwent complete excision of the tumor.

OUTCOMES

The symptoms of cancer cachexia disappeared gradually after operation. Recurrence and metastasis were not shown during follow-up for 5 years.

LESSONS

Myopericytoma are generally considered benign with an indolent clinical course, and a few reports have described malignant myopericytoma in the literature. No standard treatment is available, and complete surgical excision of the lesion may be the only potentially curative treatment. The efficacy of chemotherapy and radiation is uncertain.

Digital Myopericytoma: A Case Report and Systematic Literature Review

A myopericytoma (MP) is an exceedingly rare perivascular tumor of unknown etiology. Given their potential for mimicry and malignancy, MP tumors pose a unique challenge for surgeons and may be overlooked on differential diagnosis. We present a case report of an otherwise healthy 33-year-old right-hand dominant male who presented to our outpatient clinic with a 2-month history of painless swelling and erythema of the pulp of his left index finger. Subsequent plain film X-ray showed near-complete bony destruction of his distal phalanx. Pathological evaluation of an incisional biopsy showed a benign variant of MP. The lesion was treated by excision with tumor shelling, and there was no evidence of recurrence 81 days postoperatively. A systematic literature review of the management and outcome of all known cases of hand and wrist MP is presented.

Myopericytoma arising adjacent to the common carotid artery: Case report and systematic review of deep located neck myopericytomas

BACKGROUND

Myopericytoma is a perivascular tumor of the skin and subcutaneous tissue of the extremities, it is a rare finding in the head and neck, and even rarer is its deep location.

METHODS

A 38-year-old woman presented with a slowly growing mass at the right carotid triangle. Contrast-enhanced CT scan revealed a moderately enhancing mass. At surgery, the tumor was firmly attached to the common carotid artery, making it necessary to excise a small portion of the vessel wall.

RESULTS

The histopathologic report was myopericytoma. The postoperative course was uneventful, without tumor recurrence.

CONCLUSION

The very few deep located myopericytomas at the head and neck region show a predilection to appear near the great neck vessels with a possibility to require vascular repair, or at the parotid space where they can be multicentric. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2479-E2482, 2016.

Intravascular myopericytoma in the heel: case report and literature review

Intravascular myopericytoma (IVMP), regarded as a variant of myopericytoma, is a rare tumor. Very few cases have been described, none in the foot.The first case of IVMP located in the heel of the foot is described in this article. A literature review is reported of all cases of IVMP published in the English literature.A 48-year-old man possessed an IVMP on the heel of the right foot. The physical examination and histopathological and ultrasound studies are described. The literature review yielded 5 cases of IVMP, 2 of which were in the thigh and 1 each in the oral mucosa, the periorbital region, and the leg.The possibility that these lesions may be malignant suggests that the histopathological study of vascular tumors should include immunohistochemical tests.

Myopericytoma of the posterior cranial fossa

Myopericytoma is a soft tissue tumour believed to be derived from perivascular myoid cells. They are typically found in subcutaneous tissues in the extremities. Intracranial myopericytomas are exceptionally rare. Here we report a man with an asymptomatic posterior fossa myopericytoma with evidence of dural infiltration.

Myopericytoma of the tongue: a case report

Myopericytoma is a rare benign tumour composed of pericytic cells that show myoid differentiation and have a tendency for concentric perivascular growth. It belongs to a spectrum ofperivascular myoid cell neoplasms. To date, only a small number of cases of myopericytoma involving the oral cavity have been reported. We describe a case of myopericytoma presenting as a slowly growing tongue nodule in a 61-year-old woman. A diagnosis of myopericytoma was established with the histopathological findings combined with immunohistochemical staining. Myopericytoma should be included in the differential diagnosis of well-circumscribed, slow-growing lesions of the oral cavity.

Smooth muscle tumors of soft tissue and non-uterine viscera: biology and prognosis

Smooth muscle tumors are here considered an essentially dichotomous group composed of benign leiomyomas and malignant leiomyosarcomas. Soft tissue smooth muscle tumors with both atypia and mitotic activity are generally diagnosed leiomyosarcomas acknowledging potential for metastasis. However, lesions exist that cannot be comfortably placed in either category, and in such cases the designation 'smooth muscle tumor of uncertain biologic potential' is appropriate. The use of this category is often necessary with limited sampling, such as needle core biopsies. Benign smooth muscle tumors include smooth muscle hamartoma and angioleiomyoma. A specific category of leiomyomas are estrogen-receptor positive ones in women. These are similar to uterine leiomyomas and can occur anywhere in the abdomen and abdominal wall. Leiomyosarcomas can occur at any site, although are more frequent in the retroperitoneum and proximal extremities. They are recognized by likeness to smooth muscle cells but can undergo pleomorphic evolution ('dedifferentiation'). Presence of smooth muscle actin is nearly uniform and desmin-positivity usual. This and the lack of KIT expression separate leiomyosarcoma from GIST, an important problem in abdominal soft tissues. EBV-associated smooth muscle tumors are a specific subcategory occurring in AIDS or post-transplant patients. These tumors can have incomplete smooth muscle differentiation but show nuclear EBER as a diagnostic feature. In contrast to many other soft tissue tumors, genetics of smooth muscle tumors are poorly understood and such diagnostic testing is not yet generally applicable in this histogenetic group. Leiomyosarcomas are known to be genetically complex, often showing 'chaotic' karyotypes including aneuploidy or polyploidy, and no recurrent tumor-specific translocations have been detected.

Myopericytoma of the external auditory canal and tragus

Background:

Myopericytoma is a relatively recently described skin and soft tissue tumour that demonstrates perivascular myoid cell or pericytic differentiation. Whilst the range of anatomical locations has expanded to include visceral locations, head and neck myopericytomas are rarely documented. There have been no previous reports of aural myopericytoma.

Case report:

This paper reports the clinicopathological features of a biopsy-proven, slow-growing, 20 × 20 mm, polypoid myopericytoma that involved the external auditory canal and tragus in an 18-year-old woman. Excision was curative.

Conclusion:

Heightened clinicopathological awareness of the expanding anatomical distribution of myopericytoma is critical to its diagnosis when it presents in unusual and novel locations. Myopericytoma should be added to the range of external auditory canal neoplasms, especially those characterised by an admixture of spindle cells and a prominence of blood vessels, including those with a haemangiopericytomatous pattern.

A deadly combination of AIDS, TB and cardiac tumour

Immunocompromised status in AIDS makes differential diagnosis of any symptom very difficult for a clinician. Sharp clinical judgement and plenty of investigations may be needed to reach the diagnosis, as in this case. We hereby present a case of AIDS and active tuberculosis (TB) under treatment. The patient developed acute onset multifocal neurological symptoms following an episode of fever and diarrhoea. The MRI scan revealed numerous large cerebral infarcts. On investigations to evaluate brain infarcts, we made a diagnosis of left atrial cardiac tumour. Association of cardiac tumours with AIDS has only been rarely reported. It is uncertain if these can be opportunistic tumours in AIDS. The patient successfully came out of this deadly combination of diseases, viz AIDS, TB and large brain infarcts due to atrial tumour; with almost complete recovery.

Sarcomas other than Kaposi sarcoma occurring in immunodeficiency: interpretations from a systematic literature review

PURPOSE OF REVIEW

In immunodeficiency, an increased sarcoma risk is confirmed for Kaposi's sarcoma. Whether rates of other sarcoma subtypes are elevated in the setting of immunodeficiency is not known. We therefore reviewed published case reports on HIV and AIDS patients and organ transplant recipients with sarcomas. For comparison, we assessed sarcomas in the U.S. general population using Surveillance Epidemiology End Results (SEER) data.

RECENT FINDINGS

A total of 176 non-Kaposi sarcoma were identified, 75 in people with HIV and AIDS and 101 in transplant recipients. Leiomyosarcomas (n = 101) were the most frequently reported sarcomas, followed by angiosarcomas (n = 23) and fibrohistiocytic tumors (n = 17). Leiomyosarcomas were reported with two age peaks, in children and young adults. Epstein-Barr virus (EBV) was detected in the tumor cells in 85 and 88% of leiomyosarcomas in HIV-infected people and transplant recipients, respectively. Angiosarcomas and fibrohistiocytic tumors were most frequently reported in men. Among kidney transplant recipients, 20% of sarcomas arose at the site of an arteriovenous fistula. In comparison, leiomyoscarcomas, angiosarcomas, and fibrohistiocytic tumors comprised 16.9, 3.8, and 18.7% of sarcomas in the U.S. general population.

SUMMARY

Leiomyosarcoma and angiosarcoma may occur disproportionately in immunodeficiency. Leiomyosarcomas appear causatively linked to EBV, whereas angiosarcomas might be correlated with an arteriovenous fistula. Additional studies are necessary to understand the contribution of immunodeficiency to the cause of these sarcomas.

Vascular and perivascular lesions of skin and soft tissues in children and adolescents

Vascular anomalies in children and adolescents are the most common soft tissue lesions and include reactive, malformative, and neoplastic tumefactions, with a full spectrum of benign, intermediate, and malignant neoplasms. These lesions are diagnostically challenging because of morphologic complexity and recent changes in classification systems, some of which are based on clinical features and others on pathologic findings. In recent decades, there have been significant advances in clinical diagnosis, development of new therapies, and a better understanding of the genetic aspects of vascular biology and syndromes that include unusual vascular proliferations. Most vascular lesions in children and adolescents are benign, although the intermediate locally aggressive and intermediate rarely metastasizing neoplasms are important to distinguish from benign and malignant mimics. Morphologic recognition of a vasoproliferative lesion is straightforward in most instances, and conventional morphology remains the cornerstone for a specific diagnosis. However, pathologic examination is enhanced by adjunctive techniques, especially immunohistochemistry to characterize the type of vessels involved. Multifocality may cause some uncertainty regarding the assignment of "benign" or "malignant." However, increased interest in vascular anomalies, clinical expertise, and imaging technology have contributed greatly to our understanding of these disorders to the extent that in most vascular malformations and in many tumors, a diagnosis is made clinically and biopsy is not required for diagnosis. The importance of close collaboration between the clinical team and the pathologist cannot be overemphasized. For some lesions, a diagnosis is not possible from evaluation of histopathology alone, and in a subset of these, a specific diagnosis may not be possible even after all assembled data have been reviewed. In such instances, a consensus diagnosis in conjunction with clinical colleagues guides therapy. The purpose of this review is to delineate the clinicopathologic features of vascular lesions in children and adolescents with an emphasis on their unique aspects, use of diagnostic adjuncts, and differential diagnosis.

Myopericytoma and arterial intimal thickening: the relationship between myopericytes and myointimal cells

BACKGROUND

Myopericytomas with intravascular growth have been reported and have been occasionally documented as intraarterial. In a retrospective study, we assessed intraarterial growth in myopericytomas, co-existence with arterial intimal thickening (IT) and the relationship between the two.

METHODS

This retrospective study was undertaken using 11 myopericytomas evaluated in serial microscopical sections. The results in light microscopy, electron microscopy and immunohistochemistry [including α-smooth muscle actin (SMA), desmin and h-caldesmon] were evaluated.

RESULTS

In four myopericytomas, we found intraarterial growth, with large areas of disrupted arterial wall and attachment of veins and venules, exhibiting angiogenic phenomena. Arterial IT was present and partially incorporated within the tumor (simulating medium-sized vessels). The neointimal (myointimal) cells shared morphological and immunohistochemical phenotype with the myopericytoma myoid cells, including α-SMA positivity and desmin negativity. Four of the remaining myopericytomas showed structures similar to arterial IT within the tumor.

CONCLUSIONS

The findings shown here, including the association between myopericytomas and arterial IT, the incorporation of the latter into the tumor and the similar phenotype of their respective myoid and myointimal cells, support a close relationship between these processes. Histogenically, the pericytes of the penetrating neovasculature originating from the attached venules and veins may contribute to both lesions.

Dermal Epstein Barr virus--associated leiomyosarcoma: tocsin of acquired immunodeficiency syndrome in two children

Although rare in childhood, a relatively high incidence of smooth muscle tumors are recognized in patients with AIDS, mainly in association with Epstein Barr virus (EBV) infection. Although EBV-associated smooth muscle tumors have been documented rarely in the subcutis of AIDS patients, dermal involvement has not been described to date. This report describes dermal EBV-associated leiomyosarcomas (EBV-LMS) with a nodular but superficial plaque-like appearance on the lower limbs of 2 males, 9 and 12 years old. Histopathological assessment of the excised lesions demonstrated hypercellular mitotically active dermal tumors with hyperchromatic spindle and round cells, arranged in short fascicles and sheets, with microfoci of necrosis. A smooth muscle immunophenotype, including prominent desmin immunopositivity, and positive EBV-encoded RNA in situ hybridization investigation confirmed a diagnosis of EBV-LMS. Subsequent HIV seropositivity and AIDS were confirmed in both patients. Both patients also had pulmonary tuberculosis and received antituberculous therapy. Patient 1 had a 3 cm re-excision of the prior tumor site. He received highly active antiretroviral therapy, completed 6 months of antituberculous therapy, achieved immune reconstitution and viral suppression and is tumor-free 2 years after tumor excision. Patient 2 died before further therapy. The immune status, presence, and appropriate therapy of co-existent systemic infection and highly active antiretroviral therapy in AIDS patients with EBV-LMS are crucial to a favorable outcome.

Myofibroma, Myopericytoma, Myoepithelioma, and Myofibroblastoma of Skin and Soft Tissue

The authors address a group of loosely associated, characteristically benign soft tissue neoplasms that exhibit partial myoid differentiation. The entities share similarities in morphology and in nomenclature that have historically created confusion. The authors attempt to clarify the distinct architectural patterns and the corresponding immunophenotypic and ultrastructural features that distinguish myofibroma, myopericytoma, myoepithelioma, and myofibroblastoma.

Epstein-Barr virus-associated leiomyosarcoma with cutaneous involvement in an African child with human immunodeficiency virus: a case report and review of the literature

Epstein-Barr virus (EBV)-associated smooth muscle tumors (SMTs) are infrequently encountered lesions restricted to immunocompromised patients. However, they represent the second most common tumor in children with human immunodeficiency virus (HIV) infection. We report a case of a progressively enlarging abdominal mass with cutaneous involvement in an HIV-infected, 4-year-old African girl in Malawi with clinical acquired immunodeficiency syndrome on highly active antiretroviral therapy. Analysis of an excisional specimen revealed a well-differentiated leiomyosarcoma and subsequent studies revealed diffuse nuclear positivity for Epstein-Barr virus early RNAs in lesional cells. We present a report of this case and provide a summary of the literature regarding SMTs in pediatric HIV-infected patients. In addition, we draw attention to the cutaneous manifestations of SMTs in immunosuppressed populations. We highlight EBV-related SMTs as a potential cutaneous complication of HIV infection in children and immunosuppressed patients populations as a whole.

Myopericytoma: A Pleural-Based Spindle Cell Neoplasm Off the Beaten Path

Myopericytoma is a recently described hemangiopericytoma-like neoplasm with myoid differentiation. These tumors are typically located in the subcutaneous and soft tissues of the extremities. The authors report a rare pleural-based pulmonary myopericytoma in a 58-year-old woman. The lesion was grossly homogeneous and well circumscribed. Microscopically, it was composed of densely packed spindle cells organized as whorls and short interlacing fascicles with a concentric perivascular distribution. Immunohistochemical reactions were positive for vimentin, smooth muscle actin (SMA), muscle-specific actin, and Bcl-2 and negative for desmin, h-caldesmon, cytokeratin, and CD34. Atypically, increased mitotic activity was noted, but no other malignant features were identified. The differential diagnoses are discussed with specific emphasis on solitary fibrous tumor of the pleura, which is the most common benign pleural-based spindle cell neoplasm and may be a diagnostic pitfall with potentially harmful consequences.

Myopericytoma of the kidney

Myopericytoma is a rare, histologically distinctive tumor that shows evidence of differentiation toward perivascular myoid cells. Myopericytoma is largely considered a neoplasm of skin and soft tissues, with examples of this lesion involving visceral sites being extremely limited. We present the clinical and pathologic details of an unusual case of myopericytoma occurring in the kidney. Histologically, the tumor was richly vascularized and composed of a perivascular proliferation of oval to spindle-shaped cells with bland cytologic features. The neoplastic cells were arranged in a concentric fashion around vascular lumina and also surrounded dilated, branching vessels, with a glomangiopericytomatous appearance. Mitotic figures were inconspicuous, and necrosis was absent. Perivascular myoid differentiation was supported by positive immunoreactivity for muscle-specific and smooth muscle actins, and absence of reactivity for desmin. The present case serves to expand the anatomical distribution of myopericytoma and also broadens the spectrum of primary mesenchymal neoplasms that may be encountered in the kidney.