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.

Malignant myopericytoma: Case report and review of the literature.

A 29-year-old male presented with a two-week history of a tender lesion on his right thigh. The lesion was a 1.5 cm erythematous nodule with overlying hemorrhagic crust. Histopathologic examination of a biopsy specimen revealed a highly cellular neoplasm with irregular vesicular nuclei, prominent nucleoli, and scattered mitotic figures. The cells within the lesion were rounded, ovoid and spindle shaped cells with perivascular growth. The architecture and staining pattern of the lesion were most consistent with a diagnosis of malignant myopericytoma, an exceedingly rare malignancy.

Expanding the Spectrum of Perioral Myogenic Tumors in Pediatric Patients: An SRF::NCOA2 Fused Perivascular Tumor of the Philtrum.

BACKGROUND: Perivascular tumors, which include myopericytoma and myofibroma, are rare benign soft tissue neoplasms composed of perivascular smooth muscle cells. Most demonstrate characteristic morphology and are readily diagnosed. However, a recently identified hypercellular subset shows atypical histologic features and harbor unique SRF gene fusions. These cellular perivascular tumors can mimic other more common sarcomas with myogenic differentiation. METHODS: Clinical, radiological, morphological, immunohistochemical, and molecular findings were reviewed. RESULTS: A slow-growing, fluctuant mass was noted within the philtrum at 16 months. Ultrasonography revealed a well-circumscribed cystic hypoechoic lesion. A small (1.0 cm), tan, well-circumscribed soft-tissue mass was excised after continued growth. Histologically, the encapsulated tumor was hypercellular and composed of spindle cells with predominantly-storiform architecture, focal perivascular condensation, dilated branching thin-walled vessels, increased mitoses, and a smooth muscle immunophenotype. An SRF::NCOA2 fusion was identified. CONCLUSION: We report the first case of an SRF-rearranged cellular myopericytoma in the perioral region in a young child. This case expands the differential diagnosis of perioral soft tissue tumors with myogenic differentiation. We highlight key clinical, pathological, and molecular features. As we illustrate, these rare tumors pose a considerable diagnostic challenge, and risk misdiagnosis as sarcoma, most notably spindle cell rhabdomyosarcoma.

Gene fusions in superficial mesenchymal neoplasms: Emerging entities and useful diagnostic adjuncts.

Cutaneous mesenchymal neoplasms are diagnostically challenging because of their overlapping morphology, and, often, the limited tissue in skin biopsy specimens. Molecular and cytogenetic techniques have identified characteristic gene fusions in many of these tumor types, findings that have expanded our understanding of disease pathogenesis and motivated development of useful ancillary diagnostic tools. Here, we provide an update of new findings in tumor types that can occur in the skin and superficial subcutis, including dermatofibrosarcoma protuberans, benign fibrous histiocytoma, epithelioid fibrous histiocytoma, angiomatoid fibrous histiocytoma, glomus tumor, myopericytoma/myofibroma, non-neural granular cell tumor, CIC-rearranged sarcoma, hybrid schwannoma/perineurioma, and clear cell sarcoma. We also discuss recently described and emerging tumor types that can occur in superficial locations and that harbor gene fusions, including nested glomoid neoplasm with GLI1 alterations, clear cell tumor with melanocytic differentiation and ACTIN::MITF translocation, melanocytic tumor with CRTC1::TRIM11 fusion, EWSR1::SMAD3-rearranged fibroblastic tumor, PLAG1-rearranged fibroblastic tumor, and superficial ALK-rearranged myxoid spindle cell neoplasm. When possible, we discuss how fusion events mediate the pathogenesis of these tumor types, and we also discuss the related diagnostic and therapeutic implications of these events.

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.

Myopericytomatosis: A rare entity mimicking other vascular tumours and malformations.

Myopericytoma is a rare tumour which typically presents as a benign lesion that mimics features of other more common vascular tumours and malformations. We present a case of a symptomatic diffuse myopericytomatosis of the left abdomen presenting as multiple subcutaneous vascular tumours detected on ultrasound and treated with ultrasound-guided sclerotherapy.

Uterine tumours with myogenic differentiation harbouring SRF::RELA fusions.

AIMS: In 2017, a subset of cellular variants of myofibroma and myopericytoma with a smooth muscle-like immunophenotype and harbouring recurrent SRF::RELA gene fusions was reported. Although the anatomical distribution was found to be quite broad, no tumours with these gene fusions in the female reproductive system have been illustrated to date. METHODS AND RESULTS: Herein, we report the histological and immunophenotypical features of three uterine tumours with SRF::RELA gene fusions. Microscopically, all three tumours were composed of cellular oval to spindle cells arranged in intersecting fascicles with variable amounts of collagen and a rich capillary network. Mitotic figures were scant. Regarding immunohistochemistry, diffuse staining for desmin, oestrogen receptor and progesterone receptor was observed in all three cases. The first case exhibited focal staining for h-caldesmon, whereas the latter two cases had diffuse staining. Furthermore, SRF::RELA rearrangement was observed in all three cases by using next-generation sequencing (NGS). Follow-up, ranging from 11 to 15 months, was available for these three patients, all of whom were well without evidence of disease. CONCLUSIONS: In conclusion, we reported a special group of uterine neoplasms with myogenic differentiation harbouring SRF::RELA rearrangement. Although the follow-up time was limited, morphological characteristics and other studies with follow-up data supported that this type of uterine neoplasm appeared to behave in a benign manner. Further studies with longer follow-up are needed to clarify the biological nature of this particular type of uterine tumour.

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.

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.

Intracranial malignant myopericytoma: case report and literature review.

Malignant myopericytoma is an exceedingly rare soft tissue tumour with only 14 documented cases in the scientific literature. Myopericytomas can occur in association with HIV-AIDS and have a predilection for internal organs such as the bronchus, larynx, liver and brain. Ebstein-Barr virus encoded small RNA(EBER) was positive in three out of 14 cases. In this case report we present the second documented case of a malignant myopericytoma, with a positive EBER found intracranially - specifically in the supratentorial compartment - invading the superior sagittal sinus. Gross total excision of the tumour was achieved, and the patient responded well with no recurrence with only highly active antiretroviral therapy (HAART). No chemotherapy or radiotherapy has been necessary.

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.

Pericytes in Sarcomas and Other Mesenchymal Tumors.

Tumors of mesenchymal origin are a diverse group, with >130 distinct entities currently recognized by the World Health Organization. A subset of mesenchymal tumors grow or invade in a perivascular fashion, and their potential relationship to pericytes is a matter of ongoing interest. In fact, multiple intersections exist between pericytes and tumors of mesenchymal origin. First, pericytes are the likely cell of origin for a group of mesenchymal tumors with a common perivascular growth pattern. These primarily benign tumors grow in a perivascular fashion and diffusely express canonical pericyte markers such as CD146, smooth muscle actin (SMA), platelet-derived growth factor receptor beta (PDGFR-ß), and RGS5. These benign tumors include glomus tumor, myopericytoma, angioleiomyoma, and myofibroma. Second and as suggested by animal models, pericytes may give rise to malignant sarcomas. This is not a suggestion that all sarcomas within a certain subtype arise from pericytes, but that genetic modifications within a pericyte cell type may give rise to sarcomas. Third, mesenchymal tumors that are likely not a pericyte derivative co-opt pericyte markers in certain contexts. These include the PEComa family of tumors and liposarcoma. Fourth and finally, as "guardians" that enwrap the microvasculature, nonneoplastic pericytes may be important in sarcoma disease progression.

Myopericytoma of the Base of the Finger: Radiological and Pathological Description of a Rare Benign Entity.

A previously healthy 46-year-old woman presented with a mass lesion between the bases of the fourth and fifth fingers of the right hand. The mass had grown progressively over 2 years and started to cause practical difficulties in everyday life. Imaging depicted a hypervascular and well-circumscribed soft tissue tumor with imaging characteristics of a sarcoma. The lesion was treated surgically. The final diagnosis of the specimen upon pathology was a myopericytoma, a benign smooth-muscle cell neoplasm. Myopericytoma is a rare disease entity; however, it is important because it can mimic more ominous conditions.

Myopericytoma of the Foot: A Case Report.

Myopericytoma is a rare soft tissue tumor found in the subcutaneous and superficial soft tissues in the extremities. The present study reports a unique case of myopericytomas found in the first and second toes of a patient. The masses were surgically excised, and on pathologic and immunohistochemical examination, the diagnosis of myopericytoma was made. At the follow-up visit, the patient had no recurrence of the soft tissue tumor.

Myopericytoma occurrence in the liver and stomach space: imaging performance.

BACKGROUND: Myopericytoma is a rare and usually benign tumor, which is even rarer if it occurs in the liver and stomach space. Previous reports of myopericytoma were mostly related to its pathological manifestations, while imaging reports were rare. Here, we report the computed tomography (CT), computed tomography angiography (CTA) and magnetic resonance imaging (MRI) performance for one deep myopericytoma. CASE PRESENTATION: In this study, one deep myopericytoma in the liver and stomach space is reported. A CT that was not contrast-enhanced showed a lobulated tumor with heterogeneous density, and a contrast-enhanced CT showed that the mass had progressive enhancement. CTA showed that the blood-supply of the tumor was supplied by the anterior superior pancreaticoduodenal artery and the left gastric artery. An MRI showed the lesion had isointensity on T1-weighted imaging (T1WI) and slight hyperintensity on T2-weighted imaging (T2WI). The lesion MRI enhancement characteristics were similar to the characteristics from the contrast-enhanced CT. In this case, the enhancement pattern of the tumor was the centrifugal enhancement for both the contrast-enhanced CT and MRI. After surgical resection of the tumor, the pathological diagnosis was myopericytoma, and there was no recurrence in a short-term follow-up. CONCLUSION: The myopericytoma generally has a rich blood supply. When there is necrosis in the center lesion, the lesion has peripheral enhancement. Abdominal myopericytoma could be categorized as having centrifugal enhancement.

Vascular leiomyoma of the nasal cavity: case report and literature review.

We report a case of a 54-year-old man with an angioleiomyoma originating from the right nasal floor. Nasal vascular leiomyomas are extremely rare tumours. A review of the literature revealed a limited number of cases of vascular leiomyoma in the nasal cavity. Clinically, they are characterised by nasal obstruction, epistaxis or pain as the primary symptom. Up to our knowledge, this is the first case in which a 3D CT scan was performed preoperatively. 3D CT scan reconstructions can show the delineation of the tumour very accurately helping to establish the therapeutic plan for removal. The definite diagnosis can only be confirmed by histopathology. Histopathologically, a vascular leiomyoma demonstrates proliferation of smooth muscle cells intermingled with dilated venous vessels.

Myopericytoma around the knee: mimicking a neurogenic tumour.

Myopericytoma is a rare, usually benign soft tissue tumour that arises most commonly in the dermis and subcutaneous soft tissue of the lower extremities. In this article, we present an unusual case of myopericytoma occurring in the deep soft tissue around the knee that mimicked a neurogenic tumour. Myopericytoma can be confused with neurogenic tumour when located in deep soft tissue and adjacent to nerve bundles. Preoperative MRI and colour Doppler ultrasound may help differentiate myopericytoma from neurogenic tumour by revealing the hypervascular nature of the tumour.

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.

Pericytic Lesions: A Paradigm of Overlapping Features.

Although myopericytoma and glomangiopericytoma are considered the subtypes of the group myopericytomas (MPC), they differ morphologically. Both of the tumors arise from pericytic cells. Scalp MPC are infrequent, but extranasal glomangiopericytomas are extremely rare. Herein, we report a case of a 36-year-old female presenting with slowly growing scalp swelling. Histopathology showed a dermal tumor with features of myopericytoma as well as glomangiopericytoma within the same lesion. Immunohistochemistry and reticulin staining confirmed pericytic origin but could not differentiate between the two tumors. This case report adds to the rarity and morphologic heterogeneity of the group MPC.