Myopericytoma in Kager's fat pad

Rare Case of Intravascular Myopericytoma-Imaging Characteristics and Review of the Literature

Myopericytoma is a rare vessel wall tumor, a subtype of hemangiopericytoma that usually develops subcutaneously. Intravascular myopericytoma is a rarer subtype, with only few cases reported in the literature and even fewer with imaging modalities included. We report the case of a 36-year-old man who was referred to our institution with a painless, palpable mass in the right arm and was evaluated with MRI, grey-scale and Doppler-mode ultrasound. Tumor histopathology and imaging characteristics are presented together with the role that each imaging modality played in the management of the patient.

Imaging features of myopericytoma of the breast: A case report and review of the literature

Myopericytoma is a rare perivascular tumor commonly arising in the superficial soft tissue and subcutaneous tissue of the distal extremities. We report the first case of myopericytoma occurring in the breast, focusing on the imaging and histopathological characteristics of the tumor. From an imaging perspective, myopericytoma presents a well-circumscribed, marked hypervascularity, and intense enhancement after injection of contrast material. Imaging examinations, such as ultrasonography and magnetic resonance imaging, can contribute to the detection of tumor invasion to adjacent structures or distant metastases, and provide evidence for a treatment plan.

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.

Myopericytoma/myopericytomatosis of the lower extremity in two young patients: a recently designated rare soft tissue neoplasm

Myopericytomas are rare, slow-growing benign perivascular tumors most commonly arising within the superficial subcutaneous soft tissues of the lower extremity. They represent one of several related perivascular tumors of myoid lineage with similar morphology and shared immunohistochemical profile including positive staining for smooth muscle actin. Histologically, myopericytoma exhibit concentric, perivascular proliferation of spindled myoid cells with bland elongated nuclei and associated blood vessels. A solitary well-demarcated nodule or mass is typically referred to as myopericytoma, whereas an infiltrative multinodular lesion has more recently been termed myopericytomatosis. At magnetic resonance imaging, tumors are most commonly superficial, may be well-defined (myopericytoma) or ill-defined (myopericytomatosis), and demonstrate highly vascularized, avidly enhancing soft tissue often with areas of internal hemorrhage. We report 2 cases involving the lower extremity (1 myopericytoma and 1 myopericytomatosis) occurring in young patients, focusing on the clinical, histopathologic, and radiologic characteristics of this relatively new distinct entity.

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.

Edematous processes within Kager fat pad: magnetic resonance imaging, gross anatomical, and histological studies in cadavers with clinical correlation

OBJECTIVE

To demonstrate the anatomical features of Kager fat pad (KFP) and its fasciae using magnetic resonance imaging, gross anatomy, and histology in cadavers; and to correlate the data with image findings in patients.

METHODS

The KFP was analyzed in 10 fresh human cadavers and 152 clinical cases. The retrospective clinical study was institutional review board approved. The specimens were studied by magnetic resonance imaging and sectioned for anatomical/histological correlation. Clinical cases were selected to evaluate the frequency, distribution, and patterns of edema/inflammation in KFP. The square of the Pearson product moment correlation coefficient and Student t tests were performed.

RESULTS

Fasciae about KFP are double layered and derived from the union of the fascia of the leg and flexor and peroneal retinacula. Edema in KFP could be divided into diffuse, confined anteriorly, confined posteriorly, and confined externally. Confined patterns of edema were associated with paratenonitis and fluid in the Achilles bursae (P < 0.05).

CONCLUSIONS

Four patterns of edema occur in KFP. Paratenonitis and bursal fluid were associated with confined edematous patterns. The double layer about KFP may contain edema that affects this region.

Gray-scale and power Doppler sonography and CT findings of myopericytoma of the posterior cervical space

We report the imaging, pathologic findings, and differential diagnosis of a myopericytoma presenting in the posterior cervical space of a 51-year-old man. The mass was hypervascular on power Doppler sonography and demonstrated homogeneous intense enhancement on contrast-enhanced CT. Differential diagnosis included hypervascular metastasis, Castleman disease of the hyaline vascular type, and paraganglioma of the vagus nerve. Myopericytoma should be considered in the differential diagnosis of a highly vascular soft-tissue mass of the posterior cervical space.

Myopericytoma involving the parotid gland as depicted on multidetector CT

Myopericytoma is a newly proposed subgroup of perivascular tumors in the World Health Organization classification of soft tissue tumors. In this study, we report a case of a benign myopericytoma with detailed multidetector CT (MDCT) findings in the parotid gland, a location that has not been described for this type of tumor previously. The clinical presentation, imaging features, histopathological and immunohistochemical findings, and the differential diagnosis with other tumors in the parotid gland are described and reviewed.