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 ± 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.

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.

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.

The histopathological and ultrasonographic features of myopericytoma

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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.

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.

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.