Ability of low-dose helical CT to distinguish between benign and malignant noncalcified lung nodules

STUDY OBJECTIVES: Low-dose helical CT scanning identifies early stage lung malignancies and also a large proportion of lung nodules of uncertain diagnostic and prognostic significance (ie, indeterminate nodules). The sensitivity, specificity, and predictive value of these indeterminate nodules detected by CT scanning as part of a lung cancer screening program is largely unknown. We therefore calculated the sensitivity, specificity, and predictive values of CT-detected lung nodules that were followed up at least 18 months. DESIGN: Single-arm screening trial with longitudinal follow-up. SETTING: Rural areas of United States, from 2000 to 2004. PARTICIPANTS: Former and current nuclear weapons workers, >/= 45 years old, including smokers and never-smokers, with variable exposure to occupational lung carcinogens. INTERVENTIONS: A total of 4,401 participants were CT scanned for lung cancer with an initial full chest low-dose CT scan, interval CT scans at 3, 6, and 12 months for indeterminate lung nodules (eg, nodules not immediately suspicious for lung cancer), and a 18-month, full-chest, low-dose incidence CT scan. RESULTS: We achieved follow-up for a minimum of 18 months for > 95% of 807 participants with indeterminate or suspicious lung nodules. Only 3 of 727 indeterminate nodules were identified as being malignant during the subsequent 18 months. The radiologist's designation of a nodule as suspicious had a sensitivity of 84.2% and a specificity of 96.6%. Given a prior probability of lung cancer of 2.4%, positive and negative predictive values were 37.2% and 99.6%. Overall, we detected 33 primary lung cancers, including 19 stage I cancers, 5 stage II cancers, 7 stage III-IV cancers, and 3 limited-stage small cell cancers. CONCLUSIONS: Helical CT scanning detects many indeterminate nodules, but few are malignant. CT scanning has high sensitivity and specificity to detect early lung cancer. The problem of false-positive results in helical CT scanning is limited and can be rationally managed. Current CT follow-up recommendations are supported.     

Proposal of a diagnostic algorithm for intraductal ultrasonography to distinguish between benign and malignant biliary strictures

To reexamine the recognizability of intraductal ultrasonography (IDUS) findings from an imaging database and propose a novel algorithm for clinical application. IDUS images of 102 patients who had undergone IDUS examinations for indeterminate causes of common bile duct dilation were independently reviewed by two endoscopists. The strength of the inter-rater agreement between the endoscopists was analyzed using Cohen's kappa (κ). An algorithm was implemented by arranging the IDUS characteristics according to their recognizability. The proposed algorithm was evaluated by examining the inter-rater agreement and diagnostic accuracy before and after the use of the algorithm. The strength of the inter-rater agreement was good for common bile duct stones with or without acoustic shadowing; intraluminal tumors; or bile duct wall thicknesses of more than or equal to 9 mm (κ > 0.8); followed by intraluminal hypoechoic nodules without common bile duct stone characteristics (κ = 0.771); and finally eccentric wall thickening, outer layer disruption, irregular mucosa, and destructed mural layers (κ: 0.595–0.419). Our algorithm improved the strength of inter-rater agreement with a diagnostic accuracy of 81.4%. We proposed an algorithm according to the recognizability of IDUS characteristics, and it can be used by endoscopists to evaluate such characteristics and determine the cause of biliary obstruction.     

Nuclear magnetic resonance spectroscopy of plasma to distinguish between malignant and benign diseases causing jaundice and cholestasis

The sera of 51 patients with malignant (n=25) and benign (n=26) hepatopancreatobiliary disorders were analysed by¹H magnetic resonance spectroscopy (NMR) in order to distinguish between malignant and benign diseases causing jaundice and/or cholestasis. Macromolecular linewidths were determined both manually and automatically with a computed analysis, and both methylene (CH₂) and methyl (CH₃) resonances were evaluated. The mean linewidth of the CH₃ peak was significantly narrower in the patients with malignant disease than in the patients with benign disease both in the manual and computed analyses, but no significant differences in the CH₂ peak were detected. Diagnostic sensitivity and specificity of the CH₃ peak determined in the computed analysis were 92% and 27% respectively. In the light of the current study, it seems obvious that because overlap between benign and malignant groups was too great,¹H NMR spectroscopy of plasma is not of practical value in distinguishing between benign and malignant causes of jaundice and/or cholestasis.     

CA19-9 antigen levels can distinguish between benign and malignant pancreaticobiliary disease

BACKGROUND:CA19-9 is a carbohydrate tumor-associated antigen which is frequently upregulated in pancreatobiliary neoplasia.However,it may also be elevated in patients with jaundice in the absence of a tumor due to biliary obstruction,and in other non-hepato-pancreatico-biliary conditions.This study aimed to evaluate whether CA19-9 levels could accurately differentiate between benign and malignant pancreatobiliary disease.METHODS:All patients referred to a single surgeon for investigation of pancreaticobilia...     

Diagnostic value of ultrasonography to distinguish between benign and malignant lesions in the management of thyroid nodules.

OBJECTIVE: We analyzed the sonographic characteristics of thyroid nodules and assessed the diagnostic value of ultrasonography in order to distinguish between benign and malignant lesions in terms of the management of thyroid nodules. DESIGN: We retrospectively analyzed the sonographic features of thyroid nodules in 580 patients who had been examined with fine-needle aspiration cytology or who underwent surgery for a thyroid nodule. The sonographic features that suggested malignancy include microcalcifications, an irregular or microlobulated margin, marked hypoechogenicity, and a shape that was taller than it was wide. The presence of one or more of these features indicated classification as category 3 (malignant). The absence of all of these features indicated classification as category 2 (benign). Presence of an anechogenic cystic nodule was classified as category 1 (benign). MAIN OUTCOME: Of 124 lesions classified as category 3, 60 of the lesions were malignant. Of 418 lesions classified as category 1 or 2, 409 were benign. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy based on the sonographic classification method were 87.0%, 86.5%, 48.4%, 97.8%, and 86.5%, respectively. CONCLUSIONS: Our results identified this sonographic classification as a useful tool in the differentiation of malignant nodules from benign nodules. In view of the high negative predictive value of sonographic classification, a more aggressive approach is recommended only for category 3 nodules.     

Distinguishing benign from malignant euadrenal masses

STUDY OBJECTIVE: To determine the efficacy of 131I-6-beta-iodomethylnorcholesterol (NP-59) adrenal scintigraphy in distinguishing benign from malignant euadrenal masses. DESIGN: Case series of patients with incidentally discovered unilateral, euadrenal masses. SETTING: Referral-based nuclear medicine clinics at university and affiliated Veterans Administration medical centers. PATIENTS: Consecutive sample of 119 euadrenal patients with unilateral adrenal masses discovered on computed tomographic (CT) scans for reasons other than suspected adrenal disease. INTERVENTIONS: Adrenal scintiscans done using 1 mCi of NP-59 intravenously, and gamma camera imaging 5 to 7 days later. MEASUREMENTS AND MAIN RESULTS: Mean lesion diameter was 3.3 +/- 1.9 cm (SD) (95% CI: 2.9 to 3.6 cm). In 76 patients, NP-59 uptake lateralized to the abnormal adrenal seen on CT scans (concordant imaging), and in all of these patients, a diagnosis of adenoma was made by needle-aspiration biopsy, adrenalectomy, or extended follow-up with repeat CT scans that were unchanged at 6 months or later. Twenty-six patients had absent or markedly reduced NP-59 uptake in the glands identified as abnormal on CT scans (discordant imaging). These adrenal masses proved to be metastatic malignancies in 19 patients, primary adrenal neoplasms other than adenoma in 4, and adrenal cysts in 3. Bilateral, symmetric accumulation of NP-59 was seen in 17 patients, in whom the adrenal masses were shown to be metastatic malignancies in 2, and adenomas in 6 (the lesions in these cases being 2 cm or less in diameter), and lesions not truly involving the adrenal in the rest (periadrenal metastases in 4 and pseudoadrenal masses in 5). Sensitivity was 76% (26 of 34 patients; CI, 58% to 88%); specificity, 100% (85 of 85 patients; CI, 95% to 100%), and accuracy, 93% (111 of 119 patients: CI, 88% to 98%). CONCLUSIONS: Functional NP-59 scintigraphy can be used to accurately and noninvasively characterize many euadrenal masses; concordance of CT and NP-59 scans can be used to exclude the presence of a malignancy or other space-occupying adrenal lesion.     

Application of artificial intelligence using a novel EUS-based convolutional neural network model to identify and distinguish benign and malignant hepatic masses

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Case of solitary necrotic nodule of the liver difficult to distinguish from malignant hepatoma]

In a 72 years old woman, abdominal computed tomography (CT) disclosed multicentric hypervascular tumor in S4 of the liver, and it was T1.T2 by the MRI, and a high signal was presented together. Stenosis was shown by ERCP at the same site. Cholangiocellular carcinoma was suspected before operation, but malignant change was not recognized by frozen section, so the operation was finished. Later, a diagnosis of solitary necrotic nodule of the liver was established by pathological diagnosis. Solitary necrotic nodule of the liver is a benign tumor.     

E-cadherin and calretinin as immunocytochemical markers to differentiate malignant from benign serous effusions

AIM: To investigate the expressions of E-cadherin and calretinin in exfoliated cells of serous effusions and evaluate their values in distinguishing malignant effusions from benign ones. METHODS: Fresh serous effusion specimens were centrifuged and exfoliated cells were collected. Cells were then processed with a standardized procedure, including paraformaldehyde fixation, BSA-PBS solution washing and smears preparation. E-cadherin and calretinin were detected by immunocytochemistry (ICC). RESULTS: In the exfoliated cells of serous effusions, most of carcinoma cells only expressed E-cadherin, and most of mesothelial cells only expressed calretinin, and benign cells (lymphocytes and granulocytes) did not express either of them. For E-cadherin, 85.7% (30/35) of malignant effusions and 8.1% (3/37) of benign fluids were ICC-positive (P<0.001). The sensitivity of E-cadherin ICC in the diagnosis of malignant effusions was 85.7%, specificity 91.9%, and diagnostic rate 88.9%. For calretinin, 94.6% (35/37) of benign effusions and 11.4% (4/35) of malignant effusions were ICC-positive (P<0.001). The sensitivity of calretinin ICC in the diagnosis of benign effusions was 94.6%, specificity 88.6%, and diagnostic rate 91.7%. For diagnosis of benign and malignant effusions by combining E-cadherin ICC and calretinin ICC, the specificities were up to 100% and 97.1%, respectively. CONCLUSION: E-cadherin ICC and calretinin ICC are sensitive and specific in differential diagnosis of benign and malignant serous effusion specimens and specificities are evidently improved when both markers are combined.     

Melanosomal sequestration of cytotoxic drugs contributes to the intractability of malignant melanomas

Multidrug resistance mechanisms underlying the intractability of malignant melanomas remain largely unknown. In this study, we demonstrate that the development of multidrug resistance in melanomas involves subcellular sequestration of intracellular cytotoxic drugs such as cis-diaminedichloroplatinum II (cisplatin; CDDP). CDDP is initially sequestered in subcellular organelles such as melanosomes, which significantly reduces its nuclear localization when compared with nonmelanoma/KB-3-1 epidermoid carcinoma cells. The melanosomal accumulation of CDDP remarkably modulates melanogenesis through a pronounced increase in tyrosinase activity. The altered melanogenesis manifested an approximately 8-fold increase in both intracellular pigmentation and extracellular transport of melanosomes containing CDDP. Thus, our experiments provide evidence that melanosomes contribute to the refractory properties of melanoma cells by sequestering cytotoxic drugs and increasing melanosome-mediated drug export. Preventing melanosomal sequestration of cytotoxic drugs by inhibiting the functions of melanosomes may have great potential as an approach to improving the chemosensitivity of melanoma cells.     

A case of hepatic angiomyolipoma difficult to distinguish from hepatocellular carcinoma

We report a case of hepatic angiomyolipoma with uncommon clinical features. A 56-year-old man presented with a hepatic tumor in the caudate lobe. The tumor was hypoechoic on ultrasonography, showed early-phase hyperattenuation on enhanced computed tomography and did not absorb iron on superparamagnetic iron oxide-enhanced magnetic resonance imaging. Hepatocellular carcinoma was highly suspected, and the patient underwent hepatic resection. Histologically, the tumor was mainly composed of smooth muscle cells and contained small amounts of adipose cells and blood vessels. On immunohistochemical staining, the smooth muscle cells were positive for a melanocytic cell-specific monoclonal antibody. In cases with uncommon features of angiomyolipoma, it is quite difficult to distinguish angiomyolipoma from hepatocellular carcinoma.     

Leukocyte concentrations in discrimination of benign from malignant lung lesions

Malignant lung lesions are associated with significant changes in leukocyte concentrations. However, overlap of values between normal subjects and patients with cancer has limited the clinical utility of this determination. To decrease the overlap, 2,000 cells per differential determination were counted, and replicate automated cell counts were performed in blood samples obtained on different mornings between 7 and 9 A.M. Seventy-five patients who presented with undiagnosed lung lesions were analyzed. Benign and malignant lung lesions could be accurately distinguished by either relative granulocyte or lymphocyte counts. With 65.5 percent granulocytes as the cutoff, 86 percent of patients (38 of 44) proved to have lung cancer had higher values, and 97 percent of patients (30 of 31) with benign lesions had lower values. Likewise, with 28 percent lymphocytes as the cutoff, 87 percent of patients with lung cancer (39 of 44) had lower values, and 94 percent of patients (29 of 31) with benign disease had higher values. Relative monocyte counts were not different. Absolute leukocyte concentrations, although different for each group, had considerable overlap and thus were poor discriminators. These data suggest that precise analytical techniques and the use of relative leukocyte concentrations can improve the clinical utility of the leukocyte count as a discriminator of benign and malignant lung lesions.