Early Peripheral Enhancement Research Articles

Low-grade oncocytic tumor of the kidney: imaging features of a novel tumor entity.

Low-grade oncocytic tumor (LOT) is a rare renal tumor that has emerged from the spectrum of eosinophilic/oncocytic renal tumors and poses a diagnostic challenge due to its similarity to chromophobe renal cell carcinoma (CHRCC) and renal oncocytoma (RO). The imaging features of this novel tumor entity have not yet been clearly described. The purpose of this study was to describe the imaging features of LOT with radiologic-pathologic correlation. We conducted a retrospective observational study involving two expert centers. We identified 12 pathologically proven LOT with preoperative imaging available, including at least computed tomography (CT) or magnetic resonance imaging (MRI), from the past 12 years. Three experienced radiologists performed the imaging analysis independently. All tumors presented well-defined borders. Nine of the 12 LOT exhibited an early peripheral enhancement with complete or almost complete centripetal fill-in on nephrographic or delayed phases without any particular shape. Three showed a homogeneous contrast enhancement. Macroscopic fat and calcifications were not observed in any of the tumors. Early peripheral enhancement with complete or almost complete centripetal fill-in on nephrographic or delayed phases without any particular shape suggests a LOT diagnosis. Further analyses involving larger studies are needed to fully confirm these imaging characteristics. To date, a percutaneous biopsy should be performed before considering management.

Computer tomography imaging findings of adrenal cavernous hemangiomas: a report of 10 cases.

Cavernous hemangiomas (CHs) of the adrenal gland are extremely rare. To date, only a few studies of adrenal CH imaging have been reported. To analyze the computed tomography (CT) imaging findings of adrenal CHs. Ten cases of adrenal CHs confirmed by a histopathological examination were retrospectively analyzed. All of the patients had undergone unenhanced and enhanced CT examinations, and eight had also undergone multiphase CT enhancement examinations. CT characteristics, including shape, size, margin, attenuation, and enhancement patterns, were analyzed. The study included six women and four men with a mean age of 49.2 years (age range, 25-62 years) and no signs of abnormal endocrine activity. The unenhanced CTs showed well-defined, heterogeneous (n = 8) or homogeneous (n = 2) density masses with scattered (n = 8) or spread calcifications (n = 2) in six tumors. In the contrast-enhanced CTs, seven tumors appeared to be marked with heterogeneous enhancement, whereas three cases exhibited no obvious enhancement. The evaluation of the pattern of dynamic enhancement in eight patients revealed that the tumors showed early peripheral enhancement (n = 4), early central enhancement (n = 1), and mixed enhancement (n = 1) with progressive partial filling-in, and no obvious enhancement in any phases (n = 2). Adrenal CHs should be included in the differential diagnosis when an adrenal neoplasm is incidentally found and appears as a well-defined, heterogeneous mass with calcifications and various enhancement patterns, including heterogeneous enhancement with characteristic progressive partial filling-in, as well as lack of enhancement in any phase.

Peripheral hyperintense pattern on T2‐weighted magnetic resonance imaging (MRI) in breast carcinoma: Correlation with early peripheral enhancement on dynamic MRI and histopathologic findings

To investigate the correlation between the peripheral hyperintense pattern of breast carcinoma on T2-weighted images (T2WI) and the early peripheral enhancement (EPE) on dynamic magnetic resonance imaging (MRI) and to examine the histological characteristics involved in the causes thereof. The signal intensity of 131 breast carcinomas of common type on T2WI was classified into four types and the correlations between the signal intensity and the histopathological subtypes were evaluated. We investigated correlation with the peripheral hyperintense pattern on a T2WI and other findings on MR images including EPE. In addition, we also investigated the histopathological characteristics in the lesions with a peripheral hyperintense pattern. The signal intensities of the lesions on T2WI demonstrated hyperintensity, isointensity, hypointensity, and a peripheral hyperintense pattern in 26 (20%), 66 (50%), 19 (15%), and 20 (15%) lesions, respectively. A peripheral hyperintense pattern correlated with the appearance of EPE (P < 0.0001) and the degree of central fibrosis (P < 0.0001). A peripheral hyperintense pattern on T2WI is a characteristic finding observed in breast carcinomas and correlated with the appearance of EPE. The appearance of a peripheral hyperintense pattern was affected by various histopathological features in the same manner as that observed for the formation of EPE.

Sclerosed hemangioma of the liver: possible diagnostic value of diffusion-weighted magnetic resonance imaging

We present a case of a sclerosed hemangioma (SH) of the liver that showed a high apparent diffusion coefficient (ADC) value. The patient was undergoing preoperative evaluation for a metastatic breast cancer lesion when a liver mass with a diameter of 3 cm was found. It was described as a heterogeneously hyperechoic mass on ultrasonography and as a well-defined, lobulated mass with early peripheral enhancement and internal heterogeneous enhancement in the delayed phase on computed tomography. The fat-suppressed T2-weighted images demonstrated a heterogeneously hyperintense mass, which showed an ADC value of 2.01 x 10(-3) mm(2)/s. Liver metastasis and cholangiocellular carcinoma could not be excluded based on the imaging findings. After surgery, a definite diagnosis of SH was obtained. Microscopically, many hyalinized portions with poor cellular and fibrous components were observed in the tumor, and this hyalinization accompanied with liquiform degeneration, which may have been one of the causes of the high ADC value. We discuss the diagnostic value of diffusion-weighted imaging for SH of the liver.

Sclerosing Angiomatoid Nodular Transformation

AJR:192, May 2009 known, and a strong correlation with another disease process has not been found [3, 4]. SANT has a distinctive gross appearance. It is a well-circumscribed mass composed of numerous nodules derived from red pulp alternating with bands of dense fibrous tissue that coalesce to form a central, stellate fibrous scar [3]. Microscopically, SANT is characterized by multiple nodular aggregates of plump endothelial cells and pericytes lining prominent slitlike vascular spaces [2–5]. The nodules are associated with extravasated erythrocytes, and the intervening collagenous stroma contains variable numbers of reactive myofibroblasts, hemosiderin-laden macrophages, lymphocytes, and plasma cells. The endothelial cells exhibit minimal cytologic atypia, with rare mitotic activity [2–5]. Limited imaging information is conveyed by the pathology literature. Two articles provide correlative enhanced CT images [4, 5]. Both have images or descriptions depicting a hypodense mass in the early portal venous phase, with areas of peripheral enhancement that become homogeneous on more delayed imaging. Description of MR findings in one case indicates that the mass showed low signal on T1 and T2 sequences [4]. A recent report, however, describes a single case showing early peripheral enhancement progressing centripetally in a radial pattern [6]. Although the small number of cases with radiologic description precludes definitive assessment, suggestive characteristics of SANT include a well-circumscribed solitary mass of the spleen that initially shows low attenuation with areas of peripheral enhancement after the administration of contrast material. This may reflect the gross pathologic appearance of central fibrous stroma and more peripheral coalescent nodules of angiomatoid Sclerosing Angiomatoid Nodular Transformation

Two different types of ring‐like enhancement on dynamic MR imaging in breast cancer: Correlation with the histopathologic findings

To describe two different types of "ring-like enhancement" seen on dynamic magnetic resonance imaging (MRI) of breast cancer, and compare their histopathological features. A total of 326 breast carcinomas in 311 patients were evaluated regarding the existence and appearance of "ring-like enhancement" in comparison to other MR imaging and histopathological findings. Early peripheral enhancement (EPE) was observed in 81 of 326 lesions (24.8%) and delayed rim enhancement (DRE) in 110 (33.7%). Spiculated mass, invasive ductal carcinoma with abundant stroma, central fibrosis/necrosis, and a higher degree of fat invasion correlated with EPE (P < 0.001). DRE correlated with lobulated or round mass with a smooth border, invasive ductal carcinoma with scanty stroma, higher degrees of inflammatory change and surrounding compressed tissue, and less fat invasion (P <0.001). EPE correlated with the ratio of the peripheral to central blood vessel density (P = 0.0036) and DRE with the ratio of the peritumoral to peripheral lymph vessel density (P = 0.0298). The appearance of two different types of ring-like enhancement on dynamic MRI in breast cancers was affected by the morphologic features, various histological factors reflecting the growth pattern of the mass, and angiogenesis and lymphangiogenesis.

AJR Teaching File: Enlarging Splenic Mass After Nephrectomy

Radiologic Description MR images show a well-defined splenic mass with T1 isointensity (Fig. 1A) and mild heterogeneous T2 hypointensity (Fig. 1B). After administration of a superparamagnetic iron oxide (SPIO) contrast agent, the lesion does not decrease in T2 signal intensity (Fig. 1C). After administration of gadolinium contrast material, the arterial phase image shows early peripheral enhancement with central stellate hypoenhancement (Fig. 1D). On serial delayed scans, heterogeneous peripheral enhancement and progressive enhancement of the central stellate region remain (Figs. 1E and 1F).

Patterns of peripheral enhancement in breast masses: correlation of findings on contrast medium enhanced MRI with histologic features and tumor angiogenesis.

Our goal was to review patterns of peripheral enhancement on contrast-enhanced MRI of the breast and to correlate radiologic findings with pathologic features. We reviewed the MR images of 124 consecutive women with breast lesions. Peripheral enhancement was identified in 35 (32 malignant, 3 benign) lesions. MRI findings were correlated with pathologic features including microvessel density and distribution determined histologically. Early peripheral enhancement with centripetal progression was seen in invasive carcinomas with a high peripheral and a low central microvessel density, associated with fibrosis and/or necrosis (n = 18; 15 with central fibrosis, 2 with fibrosis and necrosis, and 1 with necrosis alone). Early peripheral enhancement with minimal or no change in enhancement was seen in both malignant (n = 10) and benign (n = 3) lesions. Delayed peripheral enhancement with centrifugal progression was seen in carcinomas that had an expansive growth pattern and a high marginal vessel density with or without a vascularized rim of connective tissue (n = 4). Early peripheral enhancement with centripetal progression appears to be fairly specific for carcinomas, whereas early enhancement with minimal or no centripetal progression, although more common in malignant tumors, may be seen in some benign lesions as well.

CT of giant cavernous hemangioma.

Giant hepatic cavernous hemangiomas are clinically distinct from smaller asymptomatic ones and may be confused with primary or metastatic malignancy. Hemangiomas exceeding 8 cm in diameter (mean, 13.7 cm) were studied in eight women 28-71 years old, six of whom presented with right upper quadrant discomfort and/or hepatomegaly. On unenhanced CT, seven of the masses were less dense than surrounding normal liver and one was slightly more dense than adjacent fatty liver. All masses contained additional stellate or cleftlike low-density zones, and two contained calcification. After bolus IV contrast administration, all exhibited early peripheral enhancement and partial centripetal isodense fill-in. None became completely isodense on delayed scans. Familiarity with these CT characteristics and a high index of suspicion should facilitate correct diagnosis and avert needle biopsy.