Abstract
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.