Primary Malignant Myopericytoma of the Left Atrium—A Tumor of Aggressive Biological Behavior: Report of the First Case and Review of Literature

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.

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.

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.

Primary malignant myopericytoma with cancer cachexia: Report of the first case and review of literature

RATIONALE

Malignant myopericytoma is extremely rare, with a few cases described in the English literature.

PATIENT CONCERNS

This novel study aimed to report a case of malignant myopericytoma with cancer cachexia arising in the left armpit. Also, it presented a review of the English literature regarding primary malignant myopericytoma, aiming to clarify the clinical features and potentially curative treatment. A 56-year-old male presented with an ulcerated and smelly mass involving her left armpit. The patient had obvious symptoms of cancer cachexia, including emaciation, anemia, and lower extremity edema.

DIAGNOSES

Computer tomography (CT) scan demonstrated a mass in the left armpit, with no evidence of metastasis according to the chest CT, abdominal ultrasound, and emission CT. The patient underwent a core biopsy of the mass, and a diagnosis of malignant myopericytoma was rendered.

INTERVENTIONS

He received 2 standard courses of theprubicin combined with ifosfamide chemotherapy regimen with no tumor response. Then, he subsequently underwent complete excision of the tumor.

OUTCOMES

The symptoms of cancer cachexia disappeared gradually after operation. Recurrence and metastasis were not shown during follow-up for 5 years.

LESSONS

Myopericytoma are generally considered benign with an indolent clinical course, and a few reports have described malignant myopericytoma in the literature. No standard treatment is available, and complete surgical excision of the lesion may be the only potentially curative treatment. The efficacy of chemotherapy and radiation is uncertain.

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.

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.

Malignant Myopericytoma of Shoulder: A Rare Lesion

Myopericytoma is a soft tissue tumor with perivascular myoid differentiation. It accounts for 1% of the vascular tumors and involves mostly cutaneous or subcutaneous tissue of the limbs in adults. Malignant myopericytoma is exceedingly rare. A 15-year old girl presented with slowly progressive mass over left shoulder region. Histopathology and immunohistochemistry after complete excision revealed it as malignant myopericytoma.

Incidental Detection of Subcutaneous Myopericytoma of Trunk on FDG PET/CT and Bone Scintigraphy for Imaging of Colon Cancer

Myopericytoma is a rare type of unusual soft tissue tumor with perivascular myoid differentiation. A 53-year-old man with the diagnosis of colon cancer was referred to Tc-MDP bone scan and F-FDG PET/CT for staging. A subcutaneous mass located in right lower back with heterogeneous FDG uptake was detected on PET/CT. There was increased osteoblastic activity on MDP bone scan in the same region. Mass was resected and subsequently confirmed as myopericytoma by histopathology.