Spontaneous deep vein thrombosis of the upper arm due to an intravascular myopericytoma: A case report and literature review.

INTRODUCTION: Intravascular myopericytomas are a rare type of myopericytomas. In most previously reported cases, these were benign, occurred on the legs or neck, and had low recurrence rates. We have described a unique case of an intravascular myopericytoma that caused spontaneous deep vein thrombosis. MAIN SYMPTOMS, IMPORTANT CLINICAL FINDINGS, AND MAIN DIAGNOSES: A 37-year-old man presented with sudden-onset pain and swelling in the upper arm; physical examination revealed a 10 cm, palpable, firm, and mobile lesion in the upper arm. A biopsy revealed intravascular myopericytoma; immunohistological examination revealed a lesion in the lumen of the basilic vein. The tumor comprised abundant myxoid stroma with spindle cells proliferating in a concentric perivascular manner around the blood vessel. The tumor cells stained positive for CD34 and smooth muscle actin. THERAPEUTIC INTERVENTIONS AND OUTCOMES: The patient underwent total excision of the mass under local anesthesia; no recurrence was observed thereafter. A literature review was performed using PubMed and Google Scholar; the key terms were "intravascular myopericytoma" and "IVMP." Nineteen cases of intravascular myopericytomas across 14 articles published between January 2002 and January 2022 were identified. These involved 11 men and 7 women (sex was unknown in 1 case); the ages were 22 to 80 years (mean: 59.8 ±â€…14 years). In most cases, the tumor was slow-growing, and the etiology was previous surgical history or trauma. No pain was reported by patients with tumors on the face or feet, and no recurrence was observed after surgery in any of the reported cases. Immunohistochemical staining for smooth muscle actin, h-caldesmon, calponin, and CD34 was performed for differential diagnosis. Contrary to the slow-growing nature reported in the literature, the nature related to growing in the present case was unclear that lesion was discovered because of sudden pain caused by thrombosis. However, the diagnostic method and recurrence rate in our case were similar to those in the previously reported cases. CONCLUSION: Our case shows that although intravascular myopericytomas are rare, they can cause spontaneous thrombosis. They have low recurrence rates after complete resection. Spontaneous deep vein thrombosis that occurs in rare locations must be treated after determining the causes.

A retroperitoneal myopericytoma: The first case located at the retroperitoneal area and not originate from the kidneys.

A 25-year-old woman had a mass of approximately 65 cm × 33 cm × 102 cm, located in the left paraaortic area on CT scan. It was diagnosed as retroperitoneal malignant neoplasm on imaging. Afterward, open retroperitoneal tumor excision was performed. At laparotomy, the mass was carefully dissected from the ureter, renal artery, and aorta and excised as en-bloc. The pathological result was "myopericytoma." Histologically, the pathological findings characterized a pericytic neoplasm characterized by a perivascular growth of myoid tumor cells. In addition, there were uniform, oval-shaped cells with eosinophilic cytoplasm arranged in short fascicles around blood vessels. The cytologic atypia and mitoses were absent. There are many different tumors in the retroperitoneal area. Most of these lesions are malign nature. Nevertheless, for each benign and malign neoplasm, the preoperative imaging method is generally similar. This present case showed the significant findings of myopericytoma, a benign pathology located in the retroperitoneal area.

PDGFRB and NOTCH3 Mutations are Detectable in a Wider Range of Pericytic Tumors, Including Myopericytomas, Angioleiomyomas, Glomus Tumors, and Their Combined Tumors.

Pericytic tumors are subclassified as myopericytomas, myofibromas, angioleiomyomas, and glomus tumors according to the current World Health Organization classification. These pericytic tumors form a continuous morphologic spectrum, including those with combined morphology. However, to our knowledge, no widely accepted criteria for classifying tumors with combined morphology are available. Recent studies have identified platelet-derived growth factor receptor-beta (PDGFRB) gene mutations in a subset of myofibromas, myopericytomas, and myopericytomatoses but not in angioleiomyomas. NOTCH receptor 3 (NOTCH3) mutations have been reported in a subset of infantile myofibromatosis. To assess their potential role in classifying pericytic tumors, we investigated PDGFRB and NOTCH3 mutations in 41 pericytic tumors of variable morphology, including some combined forms. Our results show these mutations to be present in a variety of pericytic tumors, such as myopericytomas (PDGFRB, 3/11; NOTCH3, 4/11), myopericytomatoses (1/2; 1/2), myofibromas (3/6; 0/6), angioleiomyomas (2/13; 3/13), and glomus tumors (5/9; 1/9). Point mutations were identified in 3 tumors in PDGFRB exon 12 (Y562C, S574F, and G576S), 12 tumors in PDGFRB exon 14 (M655I, H657L, and N666K), and 9 tumors in NOTCH3 exon 25 (A1480S/T, D1481N, G1482S, T1490A, E1491K, G1494S, and V1512A). All PDGFRB mutations and NOTCH3 G1482S, T1490A, and G1494S mutations were classified as "deleterious/damaging" by ≥4 of 6 pathogenicity prediction tools in silico. Five-mutation-positive tumors, including 1 myopericytoma-angioleiomyoma, 2 myopericytomatoses-myofibroma, 1 myofibroma-myopericytoma and 1 angioleiomyoma-myopericytoma, were of combined morphology. Therefore, we found PDGFRB and NOTCH3 mutations to be detectable in a much wider variety of pericytic tumors than previously reported and confirmed myopericytomas, myofibromas, angioleiomyomas, and glomus tumors as members harboring PDGFRB or NOTCH3 mutations. Our results thus suggest that PDGFRB or NOTCH3 mutations are not useful for subclassifying members of the pericytic tumor family.

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.

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.

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

ABSTRACT: 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.

Thoracic myopericytoma in an older adult, rare but possible: A case report.

Myopericytoma is a rare tumor generally arising from skin and soft tissues of extremities, trunk, head, and neck regions, rarely from visceral sites. An intrathoracic visceral localization may carry a broad differential diagnosis including primary lung, pleura and chest wall lesions, or metastatic lesions. To date, any radiological features have been recognized and diagnosis of myopericytoma with intrathoracic localization remains still challenging. Here, we describe the case of a subpleural lesion incidentally diagnosed in an older adult affected by gastric cancer. Radiological features did not allow a differential diagnosis between a benign lesion, a primary tumor, or a metastasis. After resection, the histological examination showed histopathological features congruent with the diagnosis of myopericytoma. This unusual presentation reflects the need to share clinical, radiological, and histopathological data about this uncommon but frequently misdiagnosed disease.

Myopericytoma presenting as a painful dark subungual discoloration.

Myopericytoma is an uncommon benign neoplasm that arises from the perivascular myoid cells. It typically presents as a painless well-circumscribed cutaneous or soft-tissue nodule, most commonly on the extremities of adults. Histologically, it is characterized by spindle-shaped myoid-appearing cells with a concentric arrangement in vessel walls, that are immunoreactive to alpha-smooth muscle actin and often for h-caldesmon, but negative for other smooth muscle markers. Herein, we present an unusual case of a painful subungual myopericytoma presenting as a dark subungual discoloration.

The histopathological and ultrasonographic features of myopericytoma.

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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.

Myopericytoma of the Parotid and Molecular Profiling: Report of a Rare Case and Review of the Literature.

Myopericytomas are uncommon tumors defined by their round to spindle shaped cells often arranged in a concentric pattern of perivascular growth. They are typically well-circumscribed, nodular, slow-growing lesions that occur in the soft tissue of the extremities. Here, we present a 30-year-old female with a 2.4 cm myopericytoma occurring in the deep lobe of the parotid gland. The diagnosis was made with detailed histopathologic and immunohistochemical findings and positive identification of the specific mutation for PDGFRß p.Asp666Lys by next generation sequencing (NGS). This is the first case report of a parotid myopericytoma with a genetic testing that shows a particular mutation that has been linked to myopericytomatosis.

Imaging features of myopericytoma arising from the parotid gland: Report of 2 cases and literature review.

RATIONALE: Myopericytoma of the parotid gland is a rare condition of which preoperative definitive diagnosis is relatively challenging. The purpose of this case report is to highlight the radiologic features of myopericytoma of parotid gland. PATIENT CONCERNS: A 62-year-old man presented with a history of a walnut-size mass in left parotid gland when yawned for half-month, and a 48-year-old woman complaint about a grape-size, painless mass behind the right ear for a month. DIAGNOSES: Radiological examinations suggested that both lesions were cyst-solid mixed lesions with relatively smoothed margins, with or without significant enhancement while the lesion without enhancement had a hemorrhage. Then a diagnosis of benign tumor arising from the parotid gland was made. Final diagnosis of myopericytoma was confirmed by histopathological and immunohistochemical examinations after surgical resection. INTERVENTIONS: Both patients underwent excision of the tumor and the superficial parotidectomy with facial nerve preservation. OUTCOMES: Both patients recovered without any intraoperative or postoperative complication and had no signs of recurrence during a 17-month and 5-year follow-up. LESSONS: Parotid gland myopericytoma is an exceedingly rare tumor which diagnosis can be challenging, and this is the first published report specifying the magnetic resonance features of the disease.

Miopericitoma mitóticamente activo / Mitotically Active Myopericytoma

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Myopericytoma arising from myopericytosis-a hitherto unrecognized entity within the lung.

Two cases of myopericytosis combined with pericytoma originating within the lung are reported. These are rare pulmonary tumors. The differential diagnosis for hemangiopericytoma and pericytic tumors with glomus elements is discussed. Both myopericytic lesions mimic other lesions, which are more commonly seen in the lung. Based on the expression of vascular growth factor receptors 2 and 3, an antiangiogenic therapy was suggested for the patient with the myopericytoma. A treatment with an angiogenesis inhibitor resulted in a regression of the tumor, but not the precursor lesion. Probably a more specific therapy using tyrosine kinase inhibitors for VEGFR2/3 might better control these myopericytic proliferations.

A Molecular Reappraisal of Glomus Tumors and Related Pericytic Neoplasms With Emphasis on NOTCH-gene Fusions.

Glomus tumors (GTs), together with myofibroma (MF), myopericytoma (MP), and angioleiomyoma (AL) are classified as members of the perivascular myoid family of tumors. The reported genetic abnormalities across these neoplasms is dissimilar, arguing against a pathogenetically unified family; half of the GT showing NOTCH-gene fusions and a smaller subset BRAF V600E mutations, while PDGFRB mutations are noted in a subset of MF and MP. This study aimed to investigate the prevalence and specificity of NOTCH-gene fusions in a large group of GT and correlate with clinical features. BRAF-VE1 and PDGFRB immunoexpression was also investigated in this cohort. A total of 93 GT and 43 other pericytic lesions (11 MP, 13 MF, and 19 AL) were selected. All cases were tested by fluorescence in situ hybridization for NOTCH1-4 and MIR143 gene abnormalities and 6 cases were investigated by targeted RNA-sequencing. Fluorescence in situ hybridization revealed NOTCH-gene rearrangements in 50 (54%) GT, 2 MP (18%), and 2 AL (11%). NOTCH-rearrangements were present in 34 (68%) benign and 16 (32%) malignant GT. Fusion-positive benign GT were overwhelmingly seen in males with a predilection for extremities, while the malignant GT occurred mostly in viscera. Among the fusion-negative GT, 88% were benign, 9% uncertain malignant potential, and 2% malignant. Half of the fusion-negative GTs occurred in the finger/subungual region. In summary, rearrangements of NOTCH genes are seen in over half of GT, with NOTCH2-MIR143 being the most common fusion (73%), while only a small subset of AL and MP share these abnormalities. The common subungual GT subset lack NOTCH-gene fusions suggesting an alternative pathogenesis. BRAF-VE1 was negative in all 37 cases studied, while strong PDGFRB staining was seen in 14 (21%) cases. Additional studies are needed to investigate the genetic alterations in the fusion-negative cases.

Miopericitoma digital distal: estudio dermatoscópico de un caso / Distal Digital Myopericytoma: A Dermoscopic Case Study

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Myopericytoma of the Neck Originating From the Middle Scalene: A Case Report.

We report the case of a myopericytoma of the neck. A 23-year-old female noticed a small, nontender mass in her left supraclavicular fossa. The mass grew over a period of 5 months, prompting the patient to seek evaluation. There were no motor or sensory deficits. Imaging suggested a mass originating from the middle scalene muscle. Computed tomography-guided core needle biopsy demonstrated a spindle cell neoplasm with smooth muscle differentiation. Complete surgical excision was performed. Histopathological and immunohistochemical evaluation of the tissue sample suggested myopericytoma. Myopericytoma is an extremely rare tumor of the head and neck. To our knowledge, this is the first reported case of a myopericytoma originating from a scalene muscle.

Novel SRF-ICA1L Fusions in Cellular Myoid Neoplasms With Potential For Malignant Behavior.

Pericytic tumors comprise a histologic continuum of neoplasms with perivascular myoid differentiation, which includes glomus tumors, myopericytoma, myofibroma, and angioleiomyoma. Despite their morphologic overlap, recent data suggest a dichotomy in their genetic signatures, including recurrent NOTCH gene fusions in glomus tumors and PDGFRB mutations in myofibromas and myopericytomas. Moreover, SRF-RELA fusions have been described in a subset of cellular variants of myofibroma and myopericytoma showing myogenic differentiation. Triggered by an index case of an unclassified cellular myoid tumor showing a novel SRF-ICA1L fusion we have investigated our files for cases showing similar histology and screened them using a combined approach of targeted RNA sequencing and fluorescence in situ hybridization. A fusion between SRF exon 4 and ICA1L exon 10 or 11 was identified in a total of 4 spindle cell tumors with similar clinicopathologic features. Clinically, the tumors were deep-seated and originated in the trunk or proximal lower extremity of adult patients (age range: 23 to 55 y). Histologically, the tumors were composed of cellular fascicles of monomorphic eosinophilic spindle cells showing increased mitotic activity, harboring densely hyalinized stroma, often with focal areas of necrosis. All 4 tumors had similar immunoprofiles with positivity for smooth muscle actin, calponin, and smooth muscle myosin heavy chain. Tumors were negative for desmin and caldesmon, markers often seen in SRF-RELA-positive tumors with similar morphology. Follow-up information was available in 3 patients. Two patients had no evidence of disease, 2 and 5 years after surgical resection. One patient, a 35-year-old male patient with a 19 cm deep-seated tumor with brisk mitotic activity (>20 mitoses in 10 HPF), developed lung metastases 7 years after initial diagnosis. In summary, we report a series of 4 cellular myoid tumors with novel SRF-ICA1L gene fusions, characterized by bland spindle cell fascicular growth, expression of specific smooth muscle markers, elevated mitotic activity, marked stromal hyalinization, focal coagulative necrosis, and potential for malignant behavior. Given the morphologic overlap with related cellular myopericytic tumors with SRF-RELA fusions, it is likely that SRF-ICA1L fusions define a similar subset of neoplasms composed of immature smooth muscle cells.