Positron emission tomography in well differentiated fetal adenocarcinoma of the lung

A 47-year-old woman with a 20 pack-year history of cigarette smoking presented with a chest x-ray demonstrating a left upper lobe lung density. Computed tomography of the chest showed a 3-cm lobulated mass in the apical left upper lobe. The lesion demonstrated intense focal uptake on FDG-PET scanning. The patient underwent left upper lobectomy. Pathology demonstrated the histologic and immunohistochemical findings of a well differentiated fetal adenocarcinoma (WDFA). The intense FDG-PET uptake and abundant glycogen stores associated with WDFA may be the result of its embryonic derivation and differential expression of glucose transporter proteins.     

Simultaneous FDG PET+/Glut1+ lung and FDG PET−/Glut1− subcarinal lymph node metastases from prostate cancer

A 78-year-old man with a history of prostate cancer and a rise in PSA presented with a new left lung mass, detected on computed tomography (CT). Positron emission tomography (PET)–CT (PET–CT) scan with 18-F fluorodeoxyglucose glucose revealed intense uptake in the lung mass without any other areas of abnormal uptake. Surgical resection of the mass and mediastinal lymph node dissection revealed metastatic adenocarcinoma from prostate cancer in the left lung mass (tumor size 5 cm) as well as in a subcarinal lymph node (tumor size 1.9 cm), which were identical on hematoxylin and eosin stains with a Gleason score of 8. The size of the subcarinal lymph node metastasis could not explain its non-visualization on PET. Glut1 stains of the lung mass were positive with moderate (2+ out of maximum 3+) reactivity in 95% of the carcinoma cells, whereas Glut1 stains of the subcarinal lymph node were negative with faint (1+ out of maximum 3+) reactivity in ca. 30% of the carcinoma cells. The low Glut1 expression in the subcarinal lymph node is the most likely explanation for its non-visualization on PET.     

18F-FDG-PET/CT findings in primary pulmonary mixed squamous cell and glandular papilloma

A 55-year-old female had an abnormal shadow on chest radiograph. Computed tomography (CT) revealed a 26-mm tumor mass in the left upper lobe. No malignant findings were obtained by bronchoscopic cytology or histopathological diagnostics, but on positron emission tomography with 18F-fluorodeoxyglucose (FDG-PET) examination the maximum SUV was 9.01 in accordance with the tumor mass shadow on CT. Video-assisted thoracoscopic surgery was performed as clinically suspected of lung cancer, and the diagnosis was pulmonary mixed squamous cell and glandular papilloma (PMSGP). Primary PMSGP is extremely rare, and this is the first to describe the PET findings of this disease.     

Accuracy of the plain radiograph in the detection of aortopulmonary lymphadenopathy

Detection of aortopulmonary window lymph node enlargement by chest radiography was assessed in 67 patients with bronchogenic carcinoma. All patients underwent computed tomography (CT). Surgical confirmation of the radiographic and CT findings was available in all patients with lymph node size smaller than 2.5 cm in diameter on CT (47 patients) and in 6 of 20 patients with nodes greater than 2.5 cm in diameter. Forty-one had normal-sized and 26 had enlarged (greater than 1.5 cm diameter) aortopulmonary nodes. Lymphadenopathy was detected on the chest radiograph in 21 of the 26 patients with enlarged nodes. It was wrongly suspected in one of the 41 patients with normal-sized aortopulmonary nodes on CT. Three patients with lymphadenopathy had a normal aortopulmonary window on the chest radiograph. In these patients, the nodes measured 1.6-2.6 cm in diameter. In two patients with enlarged nodes and in two with normal-sized nodes, the aortopulmonary window could not be assessed on the radiograph because it was obscured by concomitant atelectasis and obstructive pneumonitis of the left upper lobe. We conclude that in the absence of left upper lobe atelectasis, chest radiography has a high sensitivity (87%) and specificity (97%) in detecting aortopulmonary lymph nodes larger than 1.5 cm in diameter. In only one patient was metastatic disease detected at surgery in a node smaller than 1.5 cm diameter.     

Ring appearance on Tc-99m MIBI thoracic SPECTs and increased uptake on Tc-99m HMDP thoracic SPECTs in a pulmonary mass of small cell carcinoma

Tc-99m MIBI is taken up avidly by viable tumor tissue and does not accumulate in the necrotic carcinoma. We present a patient who underwent Tc-99m MIBI and Tc-99m HMDP thoracic SPECTs: a large area of increased MIBI uptake with central photopenia (ring appearance) in the right upper lung localizes bone imaging agent and does not localize multiple areas of intense uptake in the metastatic hilar mediastinum lymph nodes. Rapid growth of tumor cells in the lung leading to central necrosis/ischemia accounts for bone imaging agent localization in the tumor, as well as the ring-appearance of lung mass on Tc-99m MIBI imaging. These findings may reflect less viability of the lung tumor as compared with intense MIBI uptake in hilar/mediastinal lymph node uptake without bone agent localization.     

A massive renal epithelioid angiomyolipoma with multiple metastatic lymph nodes

A 47-year-old man presented with dull pain in the left upper abdomen for 1 year. Computed tomograph (CT) examination revealed a very large heterogeneously enhancing mass in the left kidney, measuring up to 28 cm. The mass was accompanied by several enlarged lymph nodes in the peri-aortic region. Radical nephrectomy was performed and pathologic evaluation revealed sheets of epithelioid cells and piecemeal necrosis consistent with malignant epithelioid angiomyolipoma (EAML) with regional lymph node metastases. The tumor cells were strongly positive for human melanosome-associated protein (HMB-45) on immunohistochemical staining. There was neither metastasis nor recurrence 2 years postoperatively. EAML is a rare tumor of mesenchymal tissue with potential for aggressive behavior. If this neoplasm is suspected based on CT features, EAML should be confirmed by pathology and immunohistochemistry.     

CT evaluation of mediastinal lymph nodes in lung cancer: influence of the lobar site of the primary neoplasm

Previous reports have shown differences in the ability of CT to detect mediastinal lymph nodes, depending on the precise mediastinal location of the nodes. Poorest correlation between findings on CT and findings at autopsy has been described for left-sided lymph nodes, particularly those in the left peribronchial region (American Thoracic Society node station 10L), suggesting that cancers of the left lung might be less well staged by CT than cancers of the right lung. The relationship between the accuracy of mediastinal lymph node staging and the location of the primary lung cancer was examined in a retrospective study. In 103 patients with non-small-cell bronchogenic carcinoma who had preoperative CT evaluation of the mediastinum, the accuracy of preoperative staging was 81% for tumors of the right lung (70 patients) and 97% for tumors of the left lung (33 patients). The conclusion is that cancers of the left lung are staged at least as accurately as cancers of the right lung, despite the fact that left-sided mediastinal nodes are depicted more poorly on CT. Subcarinal and crossover (contralateral) nodal metastases and a low prevalence of metastasis involving only region 10L were the most important factors minimizing staging differences based on the site of the primary tumor.     

Primary adrenocortical carcinoma: CT evaluation with clinical correlation

Clinical histories and CT findings were reviewed in 38 patients with primary adrenocortical carcinomas. The primary tumors exhibited central areas of low attenuation representing tumor necrosis (n = 26), irregular contrast enhancement (n = 16), detectable calcification (n = 9), and a thin, capsulelike rim surrounding the tumor (n = 7). Tumors metastasized to liver (n = 9), lung (n = 5), and lymph nodes (n = 5). In eight of nine cases of liver metastasis the primary tumor arose in the left adrenal gland. Evidence of endocrinopathy was present in each of nine patients with lesions 6 cm or less in diameter, but in only two of seven adults with lesions exceeding 15 cm in diameter. We conclude that, contrary to established concepts, adrenocortical carcinoma may present as a smooth, homogeneous, functioning mass 6 cm or less in diameter on CT.     

Giant benign solitary fibrous tumor of the pleura: PET/CT findings

A chest radiograph revealed a large left lower hemithorax mass in a 48-year-old nonsmoker woman with chronic cough and dyspnea. Whole-body contrast-enhanced PET/CT confirmed a large mass with relatively uniform mild FDG uptake (standardized uptake value=1.8). No signs of infiltration, pleural effusion, significant regional lymph nodes, or extrathoracic lesions were seen. A presumptive diagnosis of a probable benign solitary fibrous tumor of the pleura (SFTP) was considered. SFTP was confirmed at surgery. Few reported cases have described the PET/CT findings of SFTPs.     

Lymphoscintigraphy in early-stage non-small cell lung cancer with technetium-99m nanocolloids and hybrid SPECT/CT: a pilot project

Objective

The goal of our study was to determine if lymph node activity could be visualized using a hybrid single-photon emission computed tomography/computed tomography (SPECT/CT) scanner with two commonly used colloidal lymphatic radiotracers—^99mTc-antimony sulfide colloid (ASC) and ^99mTc-filtered sulfur colloid (FSC) in the setting of low-stage non-small cell lung cancer (NSCLC).

Methods

Patients undergoing CT-guided percutaneous lung biopsies for clinically suspected early-stage lung cancer were randomized to peri-lesional injection of 37 MBq (0.5 mL) of either ASC or FSC. SPECT/CT of the thorax was performed at either 1, 2, or 3 h post-injection. The images were reviewed to determine if lymph node activity separate from the injection site could be identified.

Results

24 patients were included. Lymph node activity was identified in 50 % of patients. A total of 15 lymph nodes with activity were visualized including 5 ipsilateral hilar, 6 ipsilateral mediastinal, and 4 distant locations. No contralateral mediastinal or hilar activity was visualized. There was a tendency to improved visualization with ASC and the longer 3 h wait time. Most patients also demonstrated significant pleural, tracheobronchial, and/or systemic activity.

Conclusions

SPECT/CT imaging can demonstrate lymph node activity separate from the injection site in at least some low-stage NSCLC patients with a perilesional injection of ^99mTc nanocolloid tracers. Further investigation into the role of pre-operative lymphoscintigraphy with SPECT/CT in patients with lung cancer is warranted.     

Evaluation of the "N" factor in nonsmall cell lung cancer. Correlation between computerized tomography and pathologic anatomy

PURPOSE: To evaluate the role of CT in identifying other morphological signs of metastatic lymph node involvement from non small cell bronchogenic carcinoma. This is done to improve N staging, a critical step in this disease. In fact, since diameter is the only criterion used to distinguish normal form abnormal lymph nodes, medistinal CT only has 80% diagnostic accuracy. MATERIAL AND METHODS: 137 patients with known or suspected lung cancer were examined with Helical CT during early and late arterial phases (2 min delay, 3 mm thickness, 5 mm interslice gap) to depict node characteristics. Mediastinal lymph nodes, located according to the American Thoracic Society mapping, were considered normal when they were not visible or, if visible, less than 1 cm in diameter and of homogeneous density; lymph nodes over 1 cm in diameter and homogeneous density were considered reactive. A lymph node was considered metastatic when, independent of size, the following signs were found: central hypodensity; hyperdense thin/thick rim, with nodules within; hyperdense strands or diffuse hyperdensity in perinodal adipose tissue. The tumor site was also considered. RESULTS: Seventy patients were excluded because they were inoperable. Sixty-five of the remaining 67 patients were operated on, 1 underwent mediastinoscopy and another one mediastinoscopy followed by surgery. Based on the above CT signs, 46 patients were staged as N0, 61 as N1 and 15 as N2. In 44/46 N0 patients there was agreement between anatomical and pathologic findings; 3 of the 44 patients had lymph nodes over 1 cm in diameter and with homogeneous density. Micrometastases to mediastinal lymph nodes (N2) were found at histology in 2/46 patients (CT false negatives). In the 6 N1 and the 15 N2 patients there was complete agreement between anatomical and pathologic findings; in particular, 9 N2 patients had lymph nodes less than 1 cm in diameter with signs of metastasis and 4 had lymph nodes over 1 cm in diameter with signs of metastasis and 2 had lymph nodes either over or less than 1 cm. In all N2 patients the tumor histotype and the mediastinal location were also considered relative to the lesion site. DISCUSSION: A closer correlation was found with node morphology and density than with size. Indeed, CT sensitivity, specificity and diagnostic accuracy were 97, 100 and 97%, respectively, for the former versus 52, 93 and 77% for the latter. Adenocarcinoma was the predominant histotype (70.5%) in N2 patients. Metastases to node region 4 were predominant in right upper lobe carcinomas while node region 5 was predominant in left upper lobe lesions. CONCLUSIONS: Other criteria can be associated with size to improve CT diagnostic accuracy in N staging. Technique optimization plays a major role particularly in the late, thin slice, examination phase.     

Tangential vs. defined radiotherapy in early breast cancer treatment without axillary lymph node dissection

Purpose

Recent studies have demonstrated low regional recurrence rates in early-stage breast cancer omitting axillary lymph node dissection (ALND) in patients who have positive nodes in sentinel lymph node dissection (SLND). This finding has triggered an active discussion about the effect of radiotherapy within this approach. The purpose of this study was to analyze the dose distribution in the axilla in standard tangential radiotherapy (SRT) for breast cancer and the effects on normal tissue exposure when anatomic level I–III axillary lymph node areas are included in the tangential radiotherapy field configuration.

Patients and methods

We prospectively analyzed the dosimetric treatment plans from 51 consecutive women with early-stage breast cancer undergoing radiotherapy. We compared and analyzed the SRT and the defined radiotherapy (DRT) methods for each patient. The clinical target volume (CTV) of SRT included the breast tissue without specific contouring of lymph node areas, whereas the CTV of DRT included the level I–III lymph node areas.

Results

We evaluated the dose given in SRT covering the axillary lymph node areas of level I–III as contoured in DRT. The mean V_D95?% of the entire level I–III lymph node area in SRT was 50.28?% (range, 37.31–63.24?%), V_D45 Gy was 70.1?% (54.8–85.4?%), and V_D40 Gy was 83.5?% (72.3–94.8?%). A significant difference was observed between lung dose and heart toxicity in SRT vs. DRT. The V_20 Gy and V_30 Gy of the right and the left lung in DRT were significantly higher in DRT than in SRT (p?<?0.001). The mean heart dose in SRT was significantly lower (3.93 vs. 4.72 Gy, p?=?0.005).

Conclusion

We demonstrated a relevant dose exposure of the axilla in SRT that should substantially reduce local recurrences. Furthermore, we demonstrated a significant increase in lung and heart exposure when including the axillary lymph nodes regions in the tangential radiotherapy field set-up.     

Lung metastases manifesting as pulmonary infarction by mucin and tumor embolization: radiographic, high-resolution CT, and pathologic findings.

We present a case of lung metastasis manifesting as lung infarction by mucin and tumor embolization. The radiograph and high-resolution CT showed multiple focal consolidations with ground glass attenuation in subpleural areas of both lungs. Diagnosis was made by open lung biopsy, which revealed pulmonary infarction caused by intravascular adenocarcinoma with numerous mucus emboli in pulmonary arteries. Subpleurally located consolidations on high-resolution CT correlated well with the histologic findings of lung infarction by mucin and tumor emboli.     

Determining the cause of pulmonary atelectasis: a comparison of plain radiography and CT

In a retrospective analysis of 50 patients with segmental or lobar atelectasis of the lung, chest radiographs and CT studies were compared for their abilities to distinguish whether a centrally obstructing tumor was the cause. This was done to help define the role of CT in evaluating patients with atelectasis. Atelectasis was caused by an obstructing tumor in 27 cases and a variety of other conditions in 23. The chest radiograph correctly identified an obstructing tumor as the cause of atelectasis in 24 of 27 patients on the basis of the presence of a central hilar mass or obvious bronchial abnormality; there was 89% sensitivity and 96% specificity with a 12% false-negative rate and a 4% false-positive rate. CT correctly identified all 27 obstructing carcinomas on the basis of the presence of either a central bronchial abnormality or a central hilar mass; there was 100% sensitivity and 87% specificity with a 0% false-negative rate and a 10% false-positive rate. Absence of air bronchograms or the presence of mucus-filled bronchi within the atelectatic lung were secondary CT findings that also favored the presence of an obstructing tumor. Although the chest radiograph was more specific than CT for tumor as the cause of atelectasis (96% vs 87%, respectively), it was less sensitive than CT for tumor (89% vs 100%, respectively) resulting in missed tumor diagnoses. CT identified all cases caused by obstructing tumor and successfully excluded obstructing tumor in most of the remaining cases, with an acceptable number of false-positive tumor diagnoses (10%). CT should be performed when the cause of segmental or lobar atelectasis cannot be established with certainty on the basis of the chest radiograph.     

甲状腺髓样癌的CT表现及病理基础

目的：探讨甲状腺髓样癌（MTC）的CT表现特点和病理基础。方法：回顾性分析了28例经手术病理证实的MTC的CT表现，并与病理所见作对照研究。结果：肿瘤侵及一叶甲状腺22例，双叶6例。5例密度不均匀，23例表现为均匀低密度实质性占位（弥漫型19例）；25例增强扫描，17例原发灶轻度强化。淋巴结转移20例，其中行增强扫描的18例转移淋巴结多强化明显。对照病理，5例密度不均匀者镜下见囊变坏死（3例）或肿块内夹有未被侵犯的甲状腺组织（2例），而23密度均匀者未见上述改变，肿瘤组织中细胞分布大致均匀紧密，转移淋巴结内血管丰富。结论：MTC的CT表现以弥漫性均匀低密度肿块、轻度增强、多累及一叶甲状腺为特点，转移淋巴结以强化为特征。     

Subcarinal lymph node enlargement: radiographic findings and CT correlation

Detection of subcarinal lymph node enlargement on the posteroanterior chest radiograph was assessed in 90 patients who also had computed tomography (CT). Sixty of the 90 patients had normal-sized and 30 had enlarged (greater than 15 mm diameter) subcarinal lymph nodes on CT. An abnormality in the contour of the azygoesophageal recess interface was present on plain radiographs in only 23% of patients with lymphadenopathy; increased subcarinal opacity was present in 40%. The external surface of the medial wall of the right main-stem bronchus and bronchus intermedius was visible in 87% of patients with normal-sized lymph nodes but in only 27% of patients with lymphadenopathy. CT showed that the medial wall of the right main-stem and intermediate bronchi normally is delineated laterally by air within the bronchus and medially by lung or subcarinal fat. Nonvisualization may be due to replacement of lung or fat by enlarged nodes or tumor and may be helpful in assessing patients with suspected subcarinal adenopathy.     

Recurrence paralysis: computed tomographic analysis of intrathoracic findings]

The long and singular course of the inferior (recurrent) laryngeal nerve makes it very vulnerable to infiltration by tumors of various locations. In particular, mediastinal and pulmonary lesions must be considered in the case of left vocal chord palsy. Recurrent nerve paralysis caused by a tumor indicates advanced disease. We retrospectively reviewed the computed tomography (CT) findings in 29 patients with bronchogenic carcinoma or mediastinal tumors and recurrent nerve paralysis with respect to the site, size and extent of the tumor and the lymph node status. The review revealed a marked predominance of left upper lobe tumors with extensive lymph node metastases to the anterior mediastinum and the aortopulmonary window. The extent of mediastinal involvement exceeded the average involvement in a control group of 30 randomly selected patients with bronchogenic carcinoma at the time of presentation. In all patients CT demonstrated tumor tissue which could have caused the paralysis at one or more sites along the anatomical course of the recurrent nerve. In most cases the tumor was located at the aortic arch. The left paratracheal region, right paratracheal region and right pulmonary apex were affected in one case each. We conclude that in patients with cancer, CT is a suitable method for localizing a recurrent nerve lesion.     

Mediastinal lymph node detection and sizing at CT and autopsy

Although CT has assumed a major role in the preoperative evaluation of the mediastinum in patients with lung carcinoma, there is no consensus as to its accuracy or efficacy in this setting. A potential source of CT error is inaccurate detection or sizing of lymph nodes in particular mediastinal locations because of inadequate contrast with surrounding tissue or partial volume effects. We imaged five cadavers with CT and then meticulously dissected the mediastinal nodes. The nodes were measured and categorized by using the lymph node mapping scheme of the American Thoracic Society. The short axis nodal diameter was the best CT predictor of nodal volume. Excellent correlation was found between CT and autopsy for lymph node detection in right-sided mediastinal lymph nodes; poorer CT/autopsy correlation was found for left-sided lymph nodes, especially in the lower left peribronchial region. These findings suggest that CT may be less accurate in identifying left-sided mediastinal metastases.     

Imaging Findings of Castleman's Disease Localized in the Axilla: A Case Report

Castleman''s disease is a rare benign lymphoproliferative disorder of uncertain origin which most commonly involves the mediastinum but rarely affects the axilla. We report a case of localized Castleman''s disease involving the axillary lymph node. Mammography revealed a well-defined, homogeneously dense ovoid mass, 3 cm in size, in the left axilla, while gray-scale ultrasonography (US) demonstrated a well-defined, uniformly hypoechoic ovoid mass with good through transmission. Peripheral hypervascularity was observed at power Dopper US, and early rapid homogeneous enhancement at contrast-enhanced dynamic CT.     

胃肠道神经内分泌肿瘤的CT表现及病理基础

目的 分析胃肠道神经内分泌肿瘤(GEP-NETs)的CT表现及病理基础.方法 回顾性分析经病理证实的23例GEP-NETs的CT表现,并与病理结果进行对照研究.结果 23例患者中,20例CT检查发现病变,其中单纯胃肠壁增厚4例,单纯肿块形成6例,肿块并胃肠壁增厚10例,肿块最大径0.9~5.2 cm,平均(2.6±0.6)cm.CT平扫15例为均匀等密度,4例肿块内见小斑片状坏死低密度区,1例为高密度出血灶;增强扫描动脉期明显强化16例,中度强化4例.病变侵犯浆膜7例,肠系膜淋巴结肿大7例,肝脏转移2例.病理上该肿瘤位于黏膜下,呈浸润性生长,较小肿块表面肠黏膜常完整,较大者可形成溃疡,并可突破浆膜.结论 GEP-NETs病理基础决定其CT表现具有一定特征性,CT对判断该肿瘤的侵犯范围及转移情况起重要作用.