Adrenal myelolipomas: CT appearance with tiny amounts of fat and punctate calcification

Five cases of myelolipoma of the adrenal are presented which contained only tiny foci of fat along with areas of punctate calcification. This computed tomographic (CT) appearance is less common for this neoplasm and has only been described in three of 26 previously published CT cases of this adrenal tumor. The presence of even tiny amounts of fat in an adrenal mass should alert the radiologist to the probable diagnosis of myelolipoma. Small foci of calcification are also frequently associated.     

Adrenal glands in patients with congenital renal anomalies: CT appearance

The CT appearance of the adrenal glands was investigated in 30 patients with congenital renal anomalies (17 cases of unilateral renal agenesis, 11 of inferior ectopy, and 2 of crossed fused ectopy). The ipsilateral adrenal was clearly identified in 83% of these patients; in all of them, the adrenal was a paraspinal disk-shaped organ, which appeared linear on CT. Conversely, the adrenals retained their normal shape in a control group of 20 patients with acquired renal atrophy or prior simple nephrectomy.     

Adrenal cavernous hemangioma: MRI, CT, and US appearance

Two cases of rare adrenal cavernous hemangiomas are reported, one imaged with conventional X-ray techniques, US, CT, and MRI, and the other with US and CT. The CT technique clearly demonstrated calcifications and the internal structure of the lesions in both cases and peripheral rim enhancement on the postcontrast scan in one patient. Although MRI demonstrated accurately the complex nature of the lesion, the inability to visualize the calcified areas do not allow to make a specific histologic diagnosis.     

The extrapleural fat in empyema: CT appearance

Pleural empyema can be accompanied by changes in the adjacent chest wall. We examined the chest wall on computed tomographic scans in 24 patients with pleural effusions. Eighteen patients had pleural empyema and six had transudative effusions. Of the 18 empyema patients, 13 had abnormally high attenuation in the extrapleural tissues. In 12 of these 13, the high attenuation was probably caused by reaction to the pleural infection. In two, it was probably caused by haematoma (one patient had haematoma and empyema). In five patients there was either no clear abnormality in the extrapleural space or an insufficient amount of fat to permit detection of an abnormality, or the parietal pleura could not be distinguished from the pleural fluid because intravenous contrast medium was not given. Of the six patients with proven transudative pleural effusions, all had extrapleural fat which appeared normal. Abnormally high attenuation in the extrapleural tissues can be expected to accompany exudative pleural effusion, particularly empyema, but not transudative effusion.     

Bilateral extra-adrenal perirenal myelolipomas: CT features

Myelolipomas are rare benign tumours composed of adipose tissue and haematopoietic cells that are typically found in adrenal glands but have also appeared in extra-adrenal sites. Distinguishing between extra-adrenal myelolipomas and malignant tumours, such as liposarcomas, is crucial to avoid an invasive procedure. To this end, we present a comprehensive report of the CT imaging characteristics of a pathologically proven bilateral extra-adrenal perirenal myelolipoma.Myelolipomas are rare benign tumours typically found in adrenal glands [1]. Extra-adrenal myelolipomas are rare; bilateral extra-adrenal perirenal myelolipomas are far rarer [2]. Nonetheless, awareness of the CT findings of these lesions is important for establishing the diagnosis of extra-adrenal perirenal myelolipomas and for differentiating them from malignant tumours to avoid an invasive procedure. We herein present the CT imaging characteristics of a pathologically proven bilateral extra-adrenal perirenal myelolipoma.     

局限性Castleman病特征性钙化的CT表现和病理学对照

目的：讨论局限性Castleman病特征性钙化的CT表现和病理学特征。方法：22例局限性Castleman病中有5例合并钙化。瘤灶位于后腹膜腔者3例，前纵隔者2例。均经CT扫描和手术病理证实。结果：22例局限性Castleman病5例有钙化，CT均表现为中央性分布的分支状或斑点状，其中1例伴有周边壳状钙化。增强扫描均呈显著均匀强化。病理学分型为透明血管型4例，中间型1例，分支钙化均沿增生的小血管分布。结论：中央性分支状钙化和病灶显著均匀强化是局限性Castleman病定性诊断的重要特征。     

CT diagnosis of renal angiomyolipoma: the importance of detecting small amounts of fat

Six patients were reviewed who had renal angiomyolipoma (1.2-4.0 cm) in which only minimal amounts of fat were evident on CT. The fat content of the lesion was appreciated because tissue attenuation measurements of small areas of low attenuation within the tumors were performed and because thin-section (5-mm) and nonenhanced CT scans were used. The fat content of the lesions could be identified on 10-mm sections in three cases but only on 5-mm sections in three others. In two cases, fat was seen only on the nonenhanced 5-mm thin sections. Careful sampling of low-density regions within the mass must be performed because a single region of interest over the entire tumor will produce an average attenuation in the soft-tissue range. The use of 5-mm thin sections and thin, nonenhanced CT sections increases spatial and density resolution and decreases susceptibility to partial-volume effects. In a correlative study, no areas of fat were detected in a review of 100 well-circumscribed (4.0 cm or smaller) renal cell carcinomas. Detecting the existence of fat in a renal lesion will establish the diagnosis of angiomyolipoma and is the only radiologic finding that can differentiate it from renal cell carcinoma. Thus, unnecessary surgery will be avoided in these cases.     

Adrenal gland and adrenal mass calcification

With the widespread use of computed tomography (CT), it is not unusual to find calcification within the adrenal glands. There are a variety of adrenal lesions that may calcify, but usually the appearance of the calcification is not specific. However, when the pattern and morphology of the adrenal calcification are combined with the other imaging features and the appropriate clinical history, the correct diagnosis may be suggested.     

Appendicitis with bladder involvement: CT appearance

A case of appendicitis presenting with microscopic hematuria and a suprapubic mass involving the bladder is described. Computed tomography (CT) is a valuable aid in the diagnosis of atypical or otherwise unsuspected appendicitis. Besides first suggesting the diagnosis of appendicitis, CT was also able to demonstrate the full extent of the inflammatory process preoperatively in this case.     

Well-differentiated liposarcoma of the retroperitoneum with a fat–fluid level: US, CT, and MR appearance

We report a case of retroperitoneal liposarcoma with a fat–fluid level that has not been previously described. A 36-year-old man presented with abdominal distension. Ultrasonography, CT, and MR imaging showed a tumor with a fat–fluid level; nondependent fluid was characteristic of fat. Liposarcoma should be included in the differential diagnosis of tumors exhibiting a fat–fluid level. Received 27 February 1997; Revision received 21 May 1997; Accepted 26 May 1997     

US,CT, MR and percutaneous biopsy of adrenal myelolipomas

A group of eight asymptomatic patients with unilateral adrenal myelolipoma are reported. All lesions were discovered incidentally during US examinations for unrelated symptoms. A series of US, CT, and MR examinations showed typical findings in seven patients, and one patient presented atypical imaging, due to the predominance of myeloid tissue. A percutaneous CT-guided biopsy confirmed the definitive diagnosis in seven patients. Correspondence to: G. Liessi     

Adrenal myelolipoma: CT and ultrasound findings

The computed tomographic (CT) and ultrasound (US) appearances of 5 adrenal myelolipomas in 4 patients are reported. The component tissues of a myelolipoma determine its CT and US appearance. A myelolipoma consisting primarily of fat has a characteristic CT and US appearance. A myelolipoma also containing macroscopic quantities of nonfatty material (blood, calcium, or myeloid tissue) may have a nonspecific CT or US appearance if fat is not identified in the lesion. In equivocal cases, needle biopsy may be used to establish the diagnosis of myelolipoma.     

Adrenal schwannoma: CT and MRI findings

We report a case of adrenal schwannoma, an extremely rare retroperitoneal neoplasm. The patient was a 33-year-old man who presented with an abdominal mass that was discovered at abdominal sonography. Computed tomography showed an 8-cm well-circumscribed homogeneous mass that enhanced slightly after intravenous administration of contrast material. Magnetic resonance imaging showed low signal intensity on T1-weighted images and heterogeneously high signal intensity on T2-weighted images. Although these imaging findings are nonspecific, adrenal schwannomas should be included in the differential diagnosis of solid nonfunctioning adrenal tumors.     

肾上腺结核的增强CT表现特征与临床病程的相关性

目的探讨肾上腺结核的增强CT表现特征与临床病程的相关性，以提高该病的影像诊断水平。方法经临床证实的肾上腺结核30例，在CT强化图像上观察肾上腺的位置、大小、形态、密度以及强化特征，并结合临床和病理资料加以分析，采用Cochran Armitage趋势检验进行统计分析。结果肾上腺结核累及双侧共27例（90．0％），单侧3例（10．0％）。肾上腺肿块样增大13例，轻度或中度增大17例，轮廓仍保持完整。肾上腺增大密度均匀2例（6．7％），不均匀增大28例（93．3％）。周边强化16例（53．3％），钙化17例（56．7％）。经抗结核治疗后的6例复查CT示，5例双侧增大的肾上腺体积缩小或恢复正常，其内低密度消失，新出现点状钙化2例。钙化多见于临床后期，17例钙化中，病程〉12个月者10例，存在随病程增长而递增的分布趋势（x^2=7．47，P〈0．05），而周边强化则多见于临床早期，16例中有11例临床病程≤12个月，存在随病程增长而递减的分布趋势（x^2=6．60，P〈0．05）。结论肾上腺结核CT具有特征性表现，与临床病程存在一定的相关性，为临床治疗及疗效判断提供指导。