Malignant myopericytoma originating from the colon: A case report

BACKGROUND

Myopericytoma is a benign tumor that typically occurs within subcutaneous tissue and most often involves the distal extremities, followed by the proximal extremities, neck, thoracic vertebrae and oral cavity. Complete resection is often curative. Malignant myopericytoma is extremely rare and has a poor prognosis. Here, we report for the first time a case of malignant myopericytoma originating from the colon.

CASE SUMMARY

A 69-year-old male was admitted to our hospital with right upper quadrant pain for five days. Imaging suggested a liver mass with hemorrhage. A malignant hepatic tumor was the initial diagnosis. Surgical resection was performed after a complete preoperative work up. Initial postoperative pathology suggested that the mass was a malignant myoblastoma unrelated to the liver. Four months after the first surgery, an enhanced computed tomography (CT) scan revealed a recurrence of the tumor. The diagnosis of malignant myopericytoma derived from the colon was confirmed on histopathological examination of the specimen from the second surgery. The patient did not return to the hospital regularly for surveillance. The first postoperative abdominal CT examination six months after the second surgery demonstrated multiple liver metastases. Survival time between the diagnosis of the tumor to death was approximately one year.

CONCLUSION

Malignant myopericytoma is a rare cancer. Preoperative diagnosis may be difficult. Due to a lack of treatment options, prognosis is poor.

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.

Pontine Myopericytoma: Case Report and Literature Review

Myopericytoma (MPC) is a benign soft tissue tumor that develops from perivascular myoid cells and is part of the perivascular tumor group. MPC most commonly occurs in the subcutaneous soft tissues of the extremities, while intracranial MPC is remarkably rare. Herein, we report the case of a 45-year-old woman with myopericytoma who had a 2-week history of recurrent dizziness. Magnetic resonance imaging (MRI) revealed an irregular mass in the pons, with nodular enhancement of the mass on contrast-enhanced scans. The mass was considered a vascular lesion and was highly suspected to be a hemangioblastoma, prompting surgical intervention for the patient. The postoperative pathological report corrected the initial diagnosis, hemangioblastoma, to MPC. Intracranial MPC is extremely rare and there are no detailed imaging sources for this condition; furthermore, MPC occurrence in the pons has not been reported previously. This report presents the etiological characteristics intracranial MPC as visualized through MRI data alongside a comparative discussion on other reported diagnoses that resemble MPC. The case findings will provide a more widespread understanding for radiologists regarding the differential diagnosis of intracranial blood-rich supply lesions.

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.

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.