Adrenal neoplasms: CT-guided radiofrequency ablation--preliminary results

PURPOSE: To evaluate initial experience with radiofrequency (RF) ablation of adrenal neoplasms. MATERIALS AND METHODS: Thirteen adrenal masses in 12 patients (bilateral metastases in one patient) were treated with computed tomography (CT)-guided percutaneous RF ablation. Eleven adrenal lesions were metastases (five from lung cancer, four from renal cell carcinoma, and two from melanoma); one lesion was a pheochromocytoma and one was an aldosteronoma. There were 10 men and two women (average age, 58 years; range, 40-77 years) in the study; average adrenal mass diameter was 3.9 cm (range, 1-8 cm). Average number of RF applications per adrenal mass was 2.7 (range, 1-5 applications); average time per application was 7.8 minutes (range, 4-13 minutes). An internally cooled single electrode was used in five sessions; an internally cooled cluster electrode was used in eight sessions. RESULTS: Average follow-up was 11.2 months (range, 1-46 months). Eleven of 13 lesions were treated successfully with RF ablation after one session. Successful treatment was defined as lack of enhancement of the treated region on follow-up CT images and resolution of the biochemical abnormality in two patients. In two patients with large adrenal lesions (4 and 8 cm in diameter), enhancement of residual tissue was observed after one treatment session; this finding was indicative of residual tumor. One patient with thrombocytopenia that resulted from chemotherapy had a small hematoma, but no transfusion was required. No patient developed hypertension during the RF application. No patient with metastases had recurrent tumor at the treated site, and this lack of recurrence indicated effective local control; 11 patients had progression of metastatic disease at extraadrenal sites. CONCLUSION: Preliminary data suggest that CT-guided RF ablation is an effective technique for local control of adrenal neoplasms.     

Low-density pheochromocytoma on CT: a mimicker of adrenal adenoma

OBJECTIVE: Attenuation values on CT of less than 10 H are considered characteristic of adrenal adenomas. Adrenal pheochromocytomas can infrequently contain fat that could result in low attenuation on CT. The purpose of our study was to determine if pheochromocytomas could be confused with adenomas by virtue of their attenuation values on unenhanced CT. MATERIALS AND METHODS: CT attenuation and size of nine adrenal nodules producing pheochromocytoma syndrome were measured on unenhanced CT in nine patients. For five patients who received IV contrast material, washout profiles were also calculated. RESULTS: Two of the nine patients had adrenal lesions with attenuation values of less than 10 H; one had a pheochromocytoma with an attentuation of 9.0 H, and the other had a medullary hyperplasia with an attenuation of 1.8 H. These two nodules showed evidence of microscopic fat at histologic examination. No macroscopic fat was seen on the CT scans. The remaining seven patients had lesions with attenuation values exceeding 10 H (mean value, 25.6 H; range, 1.8-41 H). Mean diameter of the nine tumors (including the hyperplastic nodule) was 3.2 cm (range, 0.8-6.7 cm; SD, +/- 2.3 cm). The two low-attenuation lesions also mimicked adenomas by displaying more than 60% contrast washout on 10-min-delayed contrast-enhanced scans, unlike the other three pheochromocytomas for which we had washout data. CONCLUSION: On CT, pheochromocytomas may have attenuation values less than 10 H and also may display more than 60% washout of contrast agents on delayed scanning. Adrenal pheochromocytomas should be included with adenomas in the differential diagnosis both for masses with low attenuation on unenhanced CT and for lesions exhibiting a high percentage of contrast washout.     

Pheochromocytoma: detection by unenhanced CT

During a 2 1/2-year period, 10 patients with suspected pheochromocytoma were evaluated by unenhanced computed tomography (CT). Six adrenal masses, one hyperplastic adrenal gland, and two extraadrenal retroperitoneal masses were detected in seven patients; CT of the adrenals and retroperitoneum was normal in three patients. Scintigraphy with iodine-131 metaiodobenzylguanidine (131I-MIBG) was performed in nine of the 10 patients and corroborated the CT findings in all cases. In the three patients with normal CT and 131I-MIBG scintigraphic findings, follow-up assays of serum catecholamines were normal. In six of the seven patients with abnormal CT scans, surgical and pathologic confirmation was obtained; one patient was lost to follow-up after her CT scan. Unenhanced CT is recommended as the initial localizing procedure in patients with suspected pheochromocytoma, thereby avoiding the small but finite risk of hypertensive crisis associated with intravenous injection of urographic contrast medium.     

肾上腺间质组织肿瘤的CT和MRI表现

目的 分析５例罕见的肾上腺质组织肿瘤的ＣＴ和ＭＲＩ表现。方法 对５例经手术和病理证实的肾上腺间质组织肿瘤的ＣＴ和ＭＲＩ表现进行回顾性分析。其中右肾上腺神经纤维瘤２例,右肾上腺神经鞘瘤１例,左肾上腺纤维脂肪瘤１例,双侧肾上腺脂肪瘤１例。结果１例神经纤维瘤和１例神经鞘瘤有大的囊空区,１例神经纤维瘤显示多发性钙化和片状的增强。１例纤维脂肪瘤为Ｔ１ＷＩ低信号,Ｔ２ＷＩ稍高信号,注射钆剂后明显增强。１例双     

Overview of adrenal imaging/adrenal CT

CT is the imaging procedure of choice for the detection of most suspected adrenal masses. But except for some patients with acute adrenal hemorrhage or fat-containing myelolipoma, the precise histologic nature of an adrenal mass is not apparent from the CT image. MIBG radionuclide scanning is useful in some patients with pheochromocytoma, whereas bilateral adrenal venous sampling for hormone assay is necessary for correct lateralization in some patients with a small aldosterone-producing adenoma. The potential value of MR imaging in the characterization of adrenal masses, especially to distinguish benign adrenal cortical adenomas from metastatic disease, is now under investigation. Currently percutaneous aspiration biopsy is still necessary to make this distinction in patients with an adrenal mass and a known extra-adrenal primary neoplasm.     

Overview of adrenal imaging/adrenal CT

CT is the imaging procedure of choice for the detection of most suspected adrenal masses. But except for some patients with acute adrenal hemorrhage or fat-containing myelolipoma, the precise histologic nature of an adrenal mass is not apparent from the CT image. MIBG radionuclide scanning is useful in some patients with pheochromocytoma, whereas bilateral adrenal venous sampling for hormone assay is necessary for correct lateralization in some patients with a small aldosterone-producing adenoma. The potential value of MR imaging in the characterization of adrenal masses, especially to distinguish benign adrenal cortical adenomas from metastatic disease, is now under investigation. Currently percutaneous aspiration biopsy is still necessary to make this distinction in patients with an adrenal mass and a known extraadrenal primary neoplasm.     

Computed tomography and 131I-MIBG scintigraphy in the diagnosis of pheochromocytoma

In order to evaluate the usefulness of computed tomography (CT) and 131I meta-iodobenzylguanidine (131I-MIBG) scintigraphy for the localization of pheochromocytoma, a prospective study was undertaken in 23 patients with possible pheochromocytoma. Seventeen tumors were identified in 13 patients. Two tumors were extra-adrenal. CT was superior for locating tumors in the adrenal glands while 131I-MIBG scintigraphy was more useful in the detection of extra-adrenal pheochromocytoma. Together with adrenal and extra-adrenal pheochromocytoma, the sensitivity for locating the tumor was calculated as 82 per cent (14/17) for CT and 76 per cent (13/17) for 131I-MIBG scintigraphy, respectively. One adrenal tumor (1 cm in size) only was missed by both methods. No false positive CT scans of 131I-MIBG scintigraphy were obtained in the remaining 10 patients who had possible pheochromocytoma but were excluded. These results indicated that CT and 131I-MIBG scintigraphy were both useful tools for detecting pheochromocytoma.     

肾上腺转移瘤的CT诊断

目的探讨CT对肾上腺转移瘤的诊断价值。方法回顾性分析23例经手术病理证实的肾上腺转移瘤CT征象。结果23例肾E腺转移瘤中10例为双侧,右侧5例,左侧8例。瘤体大小在1．5cm×1．2cm～12．5cm×9．7cm。23例的33个肿块均为实质性肿块,26个肿块小于4cm,为类圆形或椭圆形,密度均匀,边界清楚,其中5例增强扫描肿块呈均匀强化;7个肿块大于4cm,呈不规则形或分叶状,密度不均匀,其内可见坏死、囊变,边缘模糊,其中2例增强扫描呈不均匀强化。结论结合临床病史,CT平扫与增强扫描能对大多数肾上腺转移瘤作出正确诊断。     

18F-FDG PET in evaluation of adrenal lesions in patients with lung cancer.

The purpose of this study was to assess the role of PET with (18)F-FDG in differentiating benign from metastatic adrenal masses detected on CT or MRI scans of patients with lung cancer. METHODS: This retrospective study analyzed (18)F-FDG PET scans of patients with lung cancer who were found to have an adrenal mass on CT or MRI scans. One hundred thirteen adrenal masses (75 unilateral and 19 bilateral; size range, 0.8-4.7 cm) were evaluated in 94 patients. PET findings were interpreted as positive if the (18)F-FDG uptake of the adrenal mass was greater than or equal to that of the liver. PET findings were interpreted as negative if the (18)F-FDG uptake of the adrenal mass was less than that of the liver. All studies were reviewed independently by 3 nuclear medicine physicians, and the results were then correlated with clinical follow-up or biopsy results when available. RESULTS: PET findings were positive in 71 adrenal masses. Sixty-seven of these were eventually considered to be metastatic adrenal disease. In the remaining 4, no changes in lesion size were noted on follow-up examinations. PET findings were negative in 42 adrenal masses, of which 37 eventually proved to be benign. Among the 5 adrenal masses that were false-negative, one was a large necrotic metastasis; 1 was a 2.4-cm lesion with central hemorrhaging, and the remaining 3 were lesions of less than 11 mm. The sensitivity, specificity, and accuracy for detecting metastatic disease were 93%, 90%, and 92%, respectively. CONCLUSION: (18)F-FDG PET is an accurate, noninvasive technique for differentiating benign from metastatic adrenal lesions detected on CT or MRI in patients with lung cancer. In addition, PET has the advantage of assessing the primary cancer sites and detecting other metastases.     

Changing role of imaging-guided percutaneous biopsy of adrenal masses: evaluation of 50 adrenal biopsies

OBJECTIVE: Prior series of percutaneous imaging-guided biopsies of adrenal masses before the advent of dedicated CT and MRI of the adrenal glands have shown that 40-57% of adrenal masses biopsied were adenomas-benign lesions requiring no further evaluation or treatment. This study was performed to assess the effect of dedicated adrenal imaging with CT and MRI on the rate of percutaneous imaging-guided biopsies of adrenal masses. MATERIALS AND METHODS: We reviewed 50 consecutive adrenal mass biopsies performed during a 48-month period. The patient demographics, technique of biopsy, pathology results, and results of any prior dedicated adrenal imaging with MRI or CT protocols were noted. RESULTS: Only six (12%) of 50 biopsies were adenomas. Five of these six cases were preceded by dedicated adrenal CT or MRI. Thirty-five cases were metastatic disease, four were adrenal cortical carcinoma, three were pheochromocytoma, and two biopsies were nondiagnostic. Overall, 20 of 50 cases were preceded by a dedicated adrenal CT or MRI examination to exclude an adenoma; in 21 of the remaining 30 cases, the imaging characteristics before biopsy were inconsistent with the potential diagnosis of an adenoma and dedicated adrenal CT or MRI was not recommended. CONCLUSION: The number of adrenal adenomas biopsied has declined markedly with the introduction of dedicated adrenal CT and MRI for adrenal adenomas. Percutaneous imaging-guided biopsy is useful in confirming the presence and nature of suspected metastatic deposits to the adrenal gland and in diagnosing or excluding adrenal adenomas in patients with equivocal imaging characteristics.     

Adrenal masses: characterization with T1-weighted MR imaging

The ability of a T1-weighted spin-echo magnetic resonance (MR) sequence to allow differentiation of benign from malignant adrenal masses at 0.5 T was investigated in 28 patients with 35 adrenal masses. All nine lesions with an adrenal mass-liver signal intensity ratio of 0.71 or less were metastases, and all 15 with a ratio of 0.78 or more were adenomas. Eleven masses (31%)--including six adenomas, three metastases, a pheochromocytoma, and a neuroblastoma--had ratios between these values. Nine of ten masses with adrenal mass-fat intensity ratios of 0.35 or less were metastases, and all 12 with ratios of 0.42 or more were benign. Eleven masses (31%), four malignant and one benign, had ratios between these values. The ratios for two masses could not be calculated due to lack of fat. The specificity of T1-weighted MR imaging in differentiating benign from malignant adrenal masses appears similar to that reported for T2-weighted imaging. However, significant overlap occurred, as has also been reported for T2-weighted imaging. While both imaging sequences may help distinguish benign from malignant adrenal masses in some cases, biopsy is still necessary when an accurate histologic diagnosis is essential.     

CT-guided percutaneous biopsy of adrenal masses. Experience of the technic in 54 neoplasm patients

Cross-sectional CT and US imaging have allowed the visualization of adrenal glands anatomy and abnormalities. In cancer patients a unilateral or bilateral adrenal enlargement may result from metastasis because the adrenal gland is one of the most common locations for metastasis in thoracic and abdominal tumors. We report our experience in 54 patients who underwent adrenal biopsy for unilateral (44 cases) or bilateral (10 cases) masses during CT examination mostly for lung cancer studies. Twenty-nine of 54 patients (53.7%) had metastatic deposits in the enlarged parenchyma. Other lesions included various pathologic conditions such as primary malignant tumors (2 carcinomas, 2 lymphomas, and 1 pheochromoblastoma) (5.5%), pheochromocytomas (3.7%), nonfunctioning adenomas (14.8%), and simple hyperplasias (12.4%). Eight of 10 patients with bilateral enlargement were metastatic; the extant 2 had simple hyperplasia. Biopsy was useless in 5 cases (9.2%), especially in the beginning and due to poor technique. All procedures were carried out with 18 and 19 G needles and under CT guidance, after standard scanning. The posterior approach was initially used, for both right (15%) and left (7.4%) lesions, but 3 pneumothoraces occurred. At present, we prefer transhepatic approach for the right adrenal gland: this access route is, in our experience, the safest and quickest. Left adrenal masses were approached anteriorly through the left hepatic lobe; when possible, in other patients, we used an oblique posterior transrenal approach, even though macroscopic hematuria occurred in 2 patients, without sequelae. We never used trans-splenic approach, even though this access has been described in literature for pancreatic masses. Transhepatic and transrenal CT-guided biopsy for adrenal masses in cancer patients provides, in our opinion, a correct and unquestionable diagnosis of possible metastasis, also for lesions smaller than 3 cm.     

肾上腺创伤的CT表现

目的 探讨肾上腺损伤(AGT)的CT表现特征.方法 回顾性分析1712例因腹部钝伤行CT检查的患者中AGT患者的CT检查结果.结果 1712例中,共发现AGT 29例(1.7%),右侧损伤23例,左侧3例,双侧3例,共32个病灶.主要CT表现:(1)肾上腺血肿:22例25个病灶,呈孤立立圆形或卵圆形肿块,平扫为高密度或混杂密度,三期动态增强扫描均无强化,肿块周围见推移张开的肾上腺肢体,呈弧形线状明显强化.(2)肾上腺肿胀:4例,表现为受损部肾上腺肢体肿胀,体积增大.(3)肾上腺弥漫性出血:3例,肾上腺被出血包埋,正常肾上腺结构消失.1例伴对比剂外溢,手术证实为肾上腺碎裂伴活动性出血.伴随征象主要包括伤侧肾上腺周围条纹状出血浸润影,膈肌脚增粗等.合并其他胸腹部脏器损伤25例.结论 AGT具有特征性CT表现,采用合理扫描技术并正确认识AGT的CT征象有助于避免漏诊和误诊.     

State-of-the-art adrenal imaging.

The adrenal gland is a common site of disease, and detection of adrenal masses has increased with the expanding use of cross-sectional imaging. Radiology is playing a critical role in not only the detection of adrenal abnormalities but in characterizing them as benign or malignant. The purpose of the article is to illustrate and describe the appropriate radiologic work-up for diseases affecting the adrenal gland. The work-up of a suspected hyperfunctioning adrenal mass (pheochromocytoma and aldosteronoma) should start with appropriate biochemical screening tests followed by thin-collimation computed tomography (CT). If results of CT are not diagnostic, magnetic resonance (MR) and nuclear medicine imaging examinations should be performed. CT has become the study of choice to differentiate a benign adenoma from a metastasis in the oncology patient. If the attenuation of the adrenal gland is over 10 HU at nonenhanced CT, contrast material-enhanced CT should be performed and washout calculated. Over 50% washout of contrast material on a 10-minute delayed CT scan is diagnostic of an adenoma. For adrenal lesions that are indeterminate at CT in the oncology patient, chemical shift MR imaging or adrenal biopsy should be performed. Certain features can be used by the radiologist to establish a definitive diagnosis for most adrenal masses (including carcinoma, infections, and hemorrhage) based on imaging findings alone.     

Disseminated histoplasmosis: abdominal CT findings in 16 patients

Since the onset of the AIDS epidemic, disseminated Histoplasma capsulatum infection has been reported with much greater frequency in both endemic and nonendemic areas. Abdominal CT scans of 16 patients with disseminated histoplasmosis were reviewed retrospectively to identify radiologic features of this disease. The diagnosis was confirmed by autopsy (three patients), bone marrow biopsy (10 patients), lymph node biopsy (three patients), bronchoscopic biopsy (three patients), liver biopsy (two patients), and/or colonoscopic biopsy (one patient). Fourteen patients had serologic evidence of human immunodeficiency virus infection. Disseminated histoplasmosis was either the only initial manifestation of AIDS (seven patients) or was accompanied simultaneously by cytomegalovirus infection (four patients), or Kaposi sarcoma, Toxoplasma encephalitis, or cryptosporidiosis (one patient each). Abdominal CT findings included hepatomegaly (63%); splenomegaly (38%); diffuse splenic hypottenuation (19%); bilateral adrenal enlargement or hypoattenuating masses (13%); and enlarged lymph nodes with homogeneous soft-tissue density (44%), diffuse or central low density (13%), or both (19%). Histoplasmosis should be included in the differential diagnosis when abdominal CT scans show such nonspecific findings as hepatomegaly, splenomegaly, enlarged soft-tissue-density or hypoattenuating lymph nodes, or adrenal enlargement or masses in an immunodeficient patient. An uncommon but possibly specific CT finding in histoplasmosis is diffuse splenic hypoattenuation.     

Adrenal gland hematomas in trauma patients

PURPOSE: To evaluate the frequency of detection of trauma-induced adrenal gland hematoma in current practice by using computed tomography (CT) and to correlate presence of adrenal hematoma with quantitative clinical indicators of injury severity. MATERIALS AND METHODS: The radiology information system and the trauma registry were searched for cases of adrenal hematoma detected at trauma CT during a 54-month period. CT images depicting adrenal masses with the published characteristics of adrenal hematoma were reviewed by readers who were unblinded to the initial interpretations. Injury severity score (ISS), associated injury, and patient outcome data were gleaned from the trauma registry. The control group comprised patients entered in the trauma registry during the study period who did not have a diagnosis of adrenal hematoma. RESULTS: Fifty-four adrenal hematomas were detected in 51 patients: 42 with right-gland, 12 with left-gland, and three with bilateral lesions. The hematomas were round or ovoid and had a mean maximum diameter of 2.8 cm +/- 0.7 (SD) and a mean attenuation of 52 HU +/- 12. Periadrenal stranding was seen with 48 (89%) hematomas. At follow-up CT, 32 of 35 hematomas had resolved or decreased in size and attenuation. One patient with adrenal hematoma had no other intraabdominal injuries. Compared with the 6,757 control patients, the 51 patients with adrenal hematoma had a higher mortality rate (10% vs 4%; P <.001, chi(2) test) and a higher mean ISS (25.2 vs 9.7; P <.01, t test). Adrenal hematoma was found in 24 (0.4%) of 5,665 trauma patients with an ISS of 0-19, as compared with six (5.0%) of 122 patients with an ISS of 40 or higher. CONCLUSION: Adrenal hematoma was detected in 51 (1.9%) of 2,692 trauma patients who underwent CT, or 0.8% of all patients (n = 6,808) entered in the trauma registry. Compared with the other trauma patients, the patients with adrenal hematomas had severe injuries associated with higher mortality.     

嗜铬细胞瘤伴双侧颈动脉体瘤影像表现并文献复习

目的 探讨1例肾上腺嗜铬细胞瘤（PCC）伴双侧颈动脉体瘤（CBT）的临床特征和影像学特点,以提高对此类病例的认识。 方法 回顾性分析1例经手术病理证实为肾上腺PCC伴双侧CBT的CT、MRI表现及临床病理特征,并复习相关文献。 结果 病人临床表现无特异性。右侧肾上腺PCC于平扫CT上密度较均一,增强后明显强化,内见低强化区。CBT于头颈部血管CT（CTA）上呈明显不均匀强化团块影,高分辨MRI（HR-MRI）呈混杂信号团块影,其内有多发血管流空信号。病理结果显示线粒体琥珀酸脱氢酶B（SDHB）（+）。 结论 肾上腺PCC合并双侧CBT临床罕见,其影像表现具有一定特征,SDHB（+）可能与病灶的多发性有关。     

Multiple adrenal masses: MRI tissue differentiation of pheochromocytoma and adenoma at 1.5 T

We present the case of 38-year-old hypertensive patient with bilateral adrenal masses and with clinical and biochemical suspicion of pheochromocytoma. Magnetic resonance imaging at 1.5 T established correct diagnosis of coexisting adrenal pheochromocytoma and adenoma (nonhyperfunctioning). The case supports the usefulness of MRI for definitive evaluation of bilateral adrenal masses in patients with suspicion of pheochromocytoma. Received 1 August 1995; Revision received 20 February 1996; Accepted 28 February 1996     

多层螺旋CT对双侧肾上腺疾病的诊断价值

目的探讨多层螺旋CT对双侧肾上腺疾病的临床诊断价值。资料与方法 34例双侧肾上腺疾病患者均行多层螺旋CT平扫,其中27例加行双期增强扫描,并行冠状面三维多平面重组(MPR)观察其影像学特征。结果 34例双侧肾上腺病变中,转移瘤20例,淋巴瘤4例,腺瘤3例,结核3例,嗜铬细胞瘤2例,皮质癌2例。转移瘤呈类圆形或不规则形,不均匀明显强化。淋巴瘤形态不规则,不均匀轻、中度强化。腺瘤边界清晰,平扫CT值<15 HU,中度强化。结核显示肾上腺弥漫性肿大、结核性肉芽肿形成及弥漫性钙化。嗜铬细胞瘤边界清晰,实性部分明显强化。皮质癌肿块较大,密度不均,强化明显但不均匀,可累及周围组织。结论多层螺旋CT是双侧肾上腺病变的首选检查方法。     

Thoracic wall involvement by Hodgkin disease and non-Hodgkin lymphoma: CT evaluation

Thoracic computed tomographic (CT) scans of 250 patients with newly diagnosed or recurrent lymphoma revealed thoracic wall involvement in 24 patients (11 with Hodgkin disease, 13 with non-Hodgkin lymphoma). Thoracic wall involvement occurred without contiguous mediastinal or parenchymal involvement in 17 patients. Of these, 13 patients had masses beneath the pectoralis muscles or within the breast, and four had masses arising from the ribs. Five additional patients had mediastinal masses with thymic involvement and parasternal extension through the thoracic wall. Pulmonary parenchymal lymphoma with thoracic wall invasion was noted in the remaining two patients. In five of nine patients receiving radiation therapy, treatment plans were modified by CT demonstration of thoracic wall lymphoma.