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PubMed1982

Histological evaluation of the nodules resected in the treatment of pulmonary metastatic disease.

During an 18 month period, 41 patients who had previously had a primary tumor removed, underwent 60 operations for resection of newly detected radiographic pulmonary nodules. Primary tumors included 16 osteogenic sarcomas, 9 malignant melanomas, 12 soft tissue sarcomas, 1 Ewing's sarcoma, 2 adenocarcinomas of the rectum, and 1 testicular teratocarcinoma. One hundred and eight-one pulmonary specimens were submitted for pathologic examination and 149 discrete nodules were found in these specimens by the pathologist (83%). Metastases represented 76-100% of nodules removed in 68% of the operations, 51-75% of nodules in 12%, 26-50% of nodules in 14%, and less than 25% of nodules in 6% of the cases. Metastatic disease was found in 90% of cases where nodules were greater than or equal of 0.5 cm in diameter, while metastases were found in on 33% of cases where the largest nodules removed were less than 0.5 cm. In only two cases did the histology of the pulmonary metastases differ from that of the primary tumor. We conclude that although benign lesions cannot be distinguished from metastases except by resection, nodules less than 0.5 cm in diameter probably should be observed for a further increase in size prior to operation.

Adenocarcinoma↗

PubMed2004

Sinorhizobium meliloti metabolism in the root nodule: a proteomic perspective.

The proteome of the model symbiotic bacterium, Sinorhizobium meliloti was examined to determine the enzymatic reactions and cell processes that occur when S. meliloti occupies the root nodules of Medicago truncatula and Melilotus alba. The proteomes of the nodule bacteria were compared to that of S. meliloti grown under laboratory cultured conditions as an additional control. All the detectable protein spots on the two-dimensional (2-D) gels between pH 4-7 were analyzed. In total, the identity of proteins in 1545 spots from 2-D gels was determined using peptide mass fingerprinting. There were clear differences in the proteome of nodule bacteria and cultured bacteria and putative nodule-specific and nodule suppressed proteins were identified. The data were analyzed using metabolic pathway prediction programs and used to review the biochemical and genetic studies that had been done previously on S. meliloti over several decades. There was a broad congruency between the proteomic and biochemical data when the overall pathways of central carbon and nitrogen metabolism were considered. A selective suite of ABC-type transporters was present in nodule bacteria that were biased towards the transport of amino acids and inorganic ions (P and Fe) suggesting that a highly specialized nutrient exchange was occurring between the nodule bacteria and the host. Proteins prominent in nodule bacteria were those involved in the pathways for vitamin synthesis and stress-related processes (chaperoning, heat shock, detoxification of reactive oxygen species, regulation of stress and osmo-regulation). Some of these proteins were found only in nodule bacteria. These results show the extent of the shift in metabolism that occurs when S. meliloti invades legume plants and establishes a nitrogen fixing symbiosis.

Biological Transport↗

PubMed1997

Phosphoenolpyruvate carboxylase protein kinase from soybean root nodules: partial purification, characterization, and up/down-regulation by photosynthate supply from the shoots.

Phosphoenolpyruvate carboxylase (PEPC) kinase was partially purified about 3000-fold from soybean root nodules by a fast-protein liquid chromatography protocol. This protein-serine kinase has an apparent native molecular mass of about 30,000 as estimated by size-exclusion chromatography. Following electrophoresis of this partially purified PEPC-kinase preparation in a denaturing gel containing dephospho maize leaf PEPC as substrate, the in situ renaturation and assay of protein kinase activity revealed two, PEPC-dependent kinase polypeptides with molecular masses of about 32 and 37 kDa. The approximately 32-kDa polypeptide was significantly more active than the approximately 37-kDa catalytic subunit. The activity of this partially purified PEPC kinase, and a less purified sample, was Ca2+-insensitive. This protein kinase preparation was able to phosphorylate purified PEPCs from soybean nodules, maize leaves, and a sorghum recombinant C4 PEPC. In contrast, this PEPC kinase was unable to phosphorylate a phosphorylation-site mutant form of sorghum C4 PEPC (S8Y), two other soybean nodule phosphoproteins [nodulin-26 and nodulin-100 (sucrose synthase)], bovine serum albumin, and histone III-S. Following in vitro phosphorylation of purified dephospho soybean nodule PEPC from stem-girdled plants by the partially purified nodule PEPC kinase, the former's activity and sensitivity to L-malate inhibition increased and decreased, respectively. Notably, the Ca2+-independent PEPC kinase activity in nodules from illuminated plants was markedly greater than that in nodules harvested from plants subjected to stem girdling or prolonged darkness. Furthermore, the kinase activity in nodules was controlled reversibly by illumination and extended darkness pretreatments of the parent plants, suggesting that photosynthate supply from the shoots is likely responsible for these striking changes in PEPC kinase activity observed in planta in the legume nodule.

Animals↗

PubMed1990

Either of two nod gene loci can complement the nodulation defect of a nod deletion mutant of Rhizobium leguminosarum bv viciae.

A deletion mutant of Rhizobium leguminosarum biovar viciae lacking the host-specific nodulation (nod) gene region (nodFEL nodMNT and nodO) but retaining the other nod genes (nodD nodABCIJ) was unable to nodulate peas or Vicia hirsuta, although it did induce root hair deformation. The mutant appeared to be blocked in its ability to induce infection threads and could be rescued for nodulation of V. hirsuta in mixed inoculation experiments with an exopolysaccharide deficient mutant (which is also Nod-). The nodulation deficiency of the deletion mutant strain could be partially restored by plasmids carrying the nodFE, nodFEL or nodFELMNT genes but not by nodLMN. Surprisingly, the mutant strain could also be complemented with a plasmid that did not carry any of the nodFELMNT genes but which did carry the nodO gene on a 30 kb cloned region of DNA. Using appropriate mutations it was established that nodO is essential for nodulation in the absence of nodFE. Thus, either of two independent nod gene regions can complement the deletion mutant for nodulation of V. hirsuta. Similar observations were made for pea nodulation except that nodL was required in addition to nodO for nodulation in the absence of the nodFE genes. These observations show that nodulation can occur via either of two pathways encoded by non-homologous genes.

Fabaceae↗

PubMed1986

Mineralized bone nodules formed in vitro from enzymatically released rat calvaria cell populations.

Single-cell suspensions obtained from sequential enzymatic digestions of fetal rat calvaria were grown in long-term culture in the presence of ascorbic acid, Na beta-glycerophosphate, and dexamethasone to determine the capacity of these populations to form mineralized bone. In cultures of osteoblastlike cells grown in the presence of ascorbic acid and beta-glycerophosphate or ascorbic acid alone, three-dimensional nodules (approximately 75 micron thick) covered by polygonal cells resembling osteoblasts could be detected 3 days after confluency. The nodules became macroscopic (up to 3 mm in diameter) after a further 3-4 days. Only in the presence of organic phosphate did they mineralize. Nodules did not develop without ascorbic acid in the medium. Dexamethasone caused a significant increase in the number of nodules. Histologically, nodules resembled woven bone and the cells covering the nodules stained strongly for alkaline phosphatase. Immunolabeling with specific antibodies demonstrated intense staining for type I collagen that was mineral-associated, a weaker staining for type III collagen and osteonectin, and undetectable staining for type II collagen. Nodules did not develop from population I and the number of nodules formed by populations II-V bore a linear relationship to the number of cells plated (r = .99). The results indicate that enzymatically released calvaria cells can form mineralized bone nodules in vitro in the presence of ascorbic acid and organic phosphate.

Animals↗

PubMed1987

Characterization of the proteolytic compartment in rat hepatocyte nodules.

Persistent liver nodules (hepatocyte nodules, neoplastic nodules) were produced in rat liver by intermittent feeding with 2-acetylaminofluorene. Dense bodies (secondary lysosomes) were purified and characterized from the nodules. The purity of the dense body fraction was 90%. The levels of various lysosomal enzyme activities were lower in these dense bodies in comparison with dense bodies from control liver. Similarly, protein degradation was 50% lower in dense bodies from liver nodules than in control liver. The number of autophagic vacuoles (AVs) in the nodular tissue increased considerably after 3 h vinblastine treatment. We have taken advantage of this expansion in an effort to isolate these organelles from liver nodules. Autophagic vacuoles have been isolated recently from liver and kidney but not from putatively premalignant liver nodules. Fraction purity of AVs from liver nodules was 95%. As with dense bodies, AVs from nodular tissue displayed lower activities of proteinases and lower rates of protein degradation when compared with their counterparts from normal liver tissue. Accordingly, the lower rate of overall protein degradation in liver nodules can be ascribed to a decrease in lysosomal activity. A diminished autophagic sequestration capacity is the most plausible explanation for the decreased rate of proteolysis in cells. This could conceivably give these nodular cells a growth advantage and assist in their selective outgrowth as well as in their transformation from neoplastic into true cancer cells.

2-Acetylaminofluorene↗

PubMed1999

Localization of H(+)-ATPases in soybean root nodules.

The localization of H(+)-ATPases in soybean (Glycine max L. cv. Stevens) nodules was investigated using antibodies against both P-type and V-type enzymes. Immunoblots of peribacteroid membrane (PBM) proteins using antibodies against tobacco and Arabidopsis H(+)-ATPases detected a single immunoreactive band at approximately 100 kDa. These antibodies recognized a protein of similar relative molecular mass in the crude microsomal fraction from soybean nodules and uninoculated roots. The amount of this protein was greater in PBM from mature nodules than in younger nodules. Immunolocalization of P-type ATPases using silver enhancement of colloidal-gold labelling at the light-microscopy level showed signal distributed around the periphery of non-infected cells in both the nodule cortex and nodule parenchyma. In the central nitrogen-fixing zone of the nodule, staining was present in both the infected and uninfected cells. Examination of nodule sections using confocal microscopy and fluorescence staining showed an immunofluorescent signal clearly visible around the periphery of individual symbiosomes which appeared as vesicles distributed throughout the infected cells of the central zone. Electron-microscopic examination of immunogold-labelled sections shows that P-type ATPase antigens were present on the PBM of both newly formed, single-bacteroid symbiosomes just released from infection threads, and on the PBM of mature symbiosomes containing two to four bacteroids. Immunogold labelling using antibody against the B-subunit of V-type ATPase from oat failed to detect this protein on symbiosome membranes. Only a very faint signal with this antibody was detected on Western blots of purified PBM. During nodule development, fusion of small symbiosomes to form larger ones containing multiple bacteroids was observed. Fusion was preceded by the formation of cone-like extensions of the PBM, allowing the membrane to make contact with the adjoining membrane of another symbiosome. We conclude that the major H(+)-ATPase on the PBM of soybean is a P-type enzyme with homology to other such enzymes in plants. In vivo, this enzyme is likely to play a critical role in the regulation of nutrient exchange between legume and bacteroids.

Microscopy, Electron↗

PubMed2004

Optimizing the surgical management of lung nodules in children with osteosarcoma: thoracoscopy for biopsies, thoracotomy for resections.

BACKGROUND: The goal of this study was to assess the role of thoracoscopy (TS) and thoracotomy (TT) in the management of lung nodules in children with osteosarcoma. METHODS: Charts of 16 osteosarcoma patients undergoing surgery for lung nodules were retrospectively analyzed for a correlation between nodule localization at CT scan, findings at surgery, and pathology. RESULTS: Fourteen TSs were performed in 10 children, eight of which were converted: two for technical problems, and six for inconsistency between CT scan and intraoperative findings. In three converted cases, TT allowed detection of more nodules than CT scan and/or TS. Eight TTs were performed as primary intention in seven children, in one as secondary surgery after a previous TS. In three cases, TT detected more nodules than CT scan. Overall, TT detected more nodules than CT scan in seven of 16 cases (sensitivity, 56.2%), six of whom had a predicted bilateral involvement. Neoplastic tissue was present in lung samples of all but three patients (86.4%). CONCLUSIONS: Lung nodules in osteosarcoma patients are usually metastases. CT scan is unreliable in detecting all the nodules, especially in the case of predicted bilateral involvement. If excision of all metastases is considered the goal of surgery, a TT approach should be chosen in patients with more than one thoracic nodule.

Adolescent↗

PubMed2006

Spatial and temporal organization of sucrose metabolism in Lotus japonicus nitrogen-fixing nodules suggests a role for the elusive alkaline/neutral invertase.

Symbiotic nitrogen fixation (SNF) in legume nodules is a highly energy demanding process, fuelled by plant-supplied carbohydrates mainly in the form of sucrose. In this study, we have combined molecular and biochemical approaches in order to study the spatial and temporal organisation of sucrose metabolism in nitrogen-fixing nodules of the model legume Lotus japonicus, with an emphasis on the neglected role of alkaline/neutral invertase. For this purpose, a full-length cDNA clone coding for an alkaline/neutral invertase isoform, termed LjInv1, was identified in a L. japonicus mature nodule cDNA libraries. Alkaline/neutral invertase activity was also found to be the predominant invertase activity in mature nodules. Real-time reverse-transcription polymerase chain reaction analysis was used in order to study the temporal expression patterns of LjInv1 in parallel with genes encoding acid invertase and sucrose synthase (SuSy) isoforms, and enzymes involved in the subsequent hexose partitioning including hexokinase, phosphoglucomutase (PGM) and phosphoglucose isomerase (PGI). The spatial organisation of sucrose metabolism was studied by in situ localisation of LjInv1 transcripts and alkaline/neutral invertase activity, and SuSy protein during nodule development. Furthermore, the spatial organisation of hexose metabolism was investigated by histochemical localisation of hexokinase, PGM and PGI activities in mature nodules. The results considered together indicate that alkaline/neutral invertase could contribute to both the Glc-1-P and Glc-6-P pools in nodules, fuelling both biosynthetic processes and SNF. Furthermore, transcript profiling analysis revealed that genes coding for hexokinase and putative plastidic PGM and PGI isoforms are upregulated during the early stages of nodule development, while the levels of transcripts corresponding to cytosolic PGM and PGI isoforms remained similar to uninfected roots, indicating a possible role of LjInv1 in producing hexoses for starch production and other biosynthetic processes in developing nodules.

Amino Acid Sequence↗

PubMed1982

Rat mammary tumors from carcinogen-induced nodules and their responsiveness to ovariectomy.

The research objective was to determine whether DMBA-induced rat mammary tumors derived from transplanted mammary nodules differ in ovarian-responsiveness from tumors originating randomly from in situ mammary parenchyma. Nodule-derived tumors were from hyperplastic alveolar outgrowths in mammary fat pads, which were either first generation outgrowths (primary nodule outgrowths) or generations 3-6 of a tumorigenic nodule line (nodule outgrowth T18). Tumors were induced in primary outgrowths by secondary exposure to DMBA in vivo or in vitro. The nodule line was not re-exposed to DMBA because of its high oncogenicity (80-85%). Despite the histological similarity of the tumor derivatives, primary nodule outgrowths and the nodule outgrowth line developed a higher proportion of ovarian-independent to ovarian-dependent tumors (1:3 and 3:4 respectively) than did in situ mammary tissues (1:9). These results are consistent with the observation that nodule outgrowths were themselves ovarian-independent.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed2005

False-positive reduction in computer-aided diagnostic scheme for detecting nodules in chest radiographs by means of massive training artificial neural network.

RATIONALE AND OBJECTIVE: We developed a technique that uses a multiple massive-training artificial neural network (multi-MTANN) to reduce the number of false-positive results in a computer-aided diagnostic (CAD) scheme for detecting nodules in chest radiographs. MATERIALS AND METHODS: Our database consisted of 91 solitary pulmonary nodules, including 64 malignant nodules and 27 benign nodules, in 91 chest radiographs. With our current CAD scheme based on a difference-image technique and linear discriminant analysis, we achieved a sensitivity of 82.4%, with 4.5 false positives per image. We developed the multi-MTANN for further reduction of the false positive rate. An MTANN is a highly nonlinear filter that can be trained with input images and corresponding teaching images. To reduce the effects of background levels in chest radiographs, we applied a background-trend-correction technique, followed by contrast normalization, to the input images for the MTANN. For enhancement of nodules, the teaching image was designed to contain the distribution for a "likelihood of being a nodule." Six MTANNs in the multi-MTANN were trained by using typical nodules and six different types of non-nodules (false positives). RESULTS: Use of the trained multi-MTANN eliminated 68.3% of false-positive findings with a reduction of one true-positive result. The false-positive rate of our original CAD scheme was improved from 4.5 to 1.4 false positives per image, at an overall sensitivity of 81.3%. CONCLUSION: Use of a multi-MTANN substantially reduced the false-positive rate of our CAD scheme for lung nodule detection on chest radiographs, while maintaining a level of sensitivity.

False Positive Reactions↗

PubMed2005

Changes in ascorbate peroxidase, catalase, guaiacol peroxidase and superoxide dismutase activities in common bean (Phaseolus vulgaris) nodules under salt stress.

To analyse nodular antioxidant enzyme expression in response to salt stress, Phaseolus vulgaris genotype BAT477 was inoculated with reference strain CIAT899, and treated with 50 mM NaCl. Plant growth, nodulation and nitrogen fixing activity were analysed. Results showed that: (1) all parameters, particularly in nodules, were affected by salt treatments, and (2) confirmed preferential growth allocation to roots. The ARA was significantly decreased by salt treatments. Protein dosage confirmed that nodules were more affected by salt treatment than were roots. We analysed superoxide dismutase, catalase, ascorbate peroxidase and peroxidase in nodules, roots and a free rhizobial strain. Our results indicated that SOD and CAT nodular isozymes had bacterial and root origins. The SOD expressed the same CuZn, Fe and Mn SOD isoforms in nodules and roots, whereas in free rhizobia we found only one Fe and Mn SOD. APX and POX nodule and root profiles had only root origins, as no rhizobial band was detected. Under salt stress, plant growth, nitrogen fixation and activities of antioxidant defense enzymes in nodules were affected. Thus, these enzymes appear to preserve symbiosis from stress turned out that NaCl salinity lead to a differential regulation of distinct SOD and POX isoenzyme. So their levels in nodules appeared to be consistent with a symbiotic nitrogen fixing efficiency hypothesis, and they seem to function as the molecular mechanisms underlying the nodule response to salinity.

Ascorbate Peroxidases↗

PubMed2005

Physiological implications of trehalase from Phaseolus vulgaris root nodules: partial purification and characterization.

The purification and characterization of trehalase from common bean nodules as well as the role of this enzyme on growth, nodulation nitrogen fixation by examining the effects of the trehalase inhibitor validamycin A, was studied. Validamycin A did not affect plant and nodule mass, neither root trehalase and nitrogenase activity; however this treatment applied at the time of sowing increased nodule number about 16% and decreased nodule trehalase activity (16-fold) and the size of nodules. These results suggest that nodule trehalase activity of Phaseolus vulgaris could be involved in nodule formation and development. In addition, acid trehalase (EC 3.2.1.28) was purified from root nodules by fractionating ammonium sulfate, column chromatography on DEAE-sepharose and sephacryl S-300, and finally on native polyacrylamide gel electrophoresis. The purified homogeneous preparation of native acid trehalase exhibited a molecular mass of 42 and 45 kDa on SDS-PAGE. The enzyme has the optimum pH 3.9, Km of 0.109 mM, Vmax of 3630 nkat mg-1 protein and is relatively heat stable. Besides trehalose, it shows maximal activity with sucrose and maltose and, to a lesser degree melibiose, cellobiose and raffinose, and it does not hydrolyze on lactose and turanose. Acid trehalase was activated by Na+, Mn2+, Mg2+, Li+, Co2+, K+ and inhibited by Fe3+, Hg+ and EDTA.

Cations↗

PubMed1997

Incidence of lung nodules found in patients undergoing lung volume reduction.

BACKGROUND: The risk of lung cancer is increased with cigarette smoking and obstructive lung disease. Patients having a lung volume reduction operation represent a high-risk population for cancer. METHODS: Between March 1994 and December 1996, 281 patients underwent a lung volume reduction operation. All had severe obstructive lung disease with hyperinflation. The incidence of lung nodules and their management were addressed. RESULTS: Of the 281 patients, 39.5% had at least one lung nodule identified. Fifty-two nodules had typical benign calcification patterns. Of the remaining nodules, 78 were resected and 20 were followed up. Seventeen nodules resected were cancerous, of which 13 were primary lung cancers. Of the resected nodules there were 28 nodules not identified by the preoperative radiologic evaluation. CONCLUSIONS: Nodules are frequently seen in patients undergoing lung volume reduction operations. The overall incidence of cancer was 6.4%, with several only identified in the pathologic examination. Survival at short follow-up has been excellent for those with primary lung cancer. Nodules seen in this group of patients should be aggressively diagnosed and managed.

Aged↗

PubMed1998

The influence of bacterial species and intensity of infections on nodule formation in insects.

Nodulation is the predominant cellular immune reaction to bacterial infection in insects. Nodulation is a complex process involving an unknown number of discrete cellular actions. Currently, there is only limited information on the signal transduction mechanisms that result in nodulation. In older larvae of the tobacco hornworm, Manduca sexta, and of the tenebrionid beetle, Zophobas atratus, eicosanoids are involved in one or more steps in the overall process, and treating these insects with inhibitors of eicosanoid biosynthesis prior to bacterial infection severely impairs their ability to form nodules. In this paper we address more detailed questions on eicosanoid-mediated nodulation. The nodulation reaction to bacterial infection occurs in all larval stages we examined, specifically, second, third, and fourth instars of M. sexta. In both species, the number of nodules formed in response to bacterial infection is related in an exponential way to the number of bacterial cells in the infection. Nodulation is also not related to larval size. We also found that nodulation intensity varies according to the species of infecting bacteria.

Journal Article↗

PubMed2003

Removal of lead from contaminated water bodies using sea nodule as an adsorbent.

Adsorption of water soluble lead on polymetallic sea nodule has been studied in detail. Complete decontamination of lead is possible by appropriate sea nodule dosing. Adsorption is also dependent on pH and best adsorption is achieved at pH 6. Beyond pH 6, the desorption of lead from sea nodule surface is practically zero. Residual metal concentrations in the filtrate after adsorption is negligible. Both Freundlich and Langmuir isotherms may reasonably explain adsorption of lead on sea nodule. Chemically bound moisture plays a very crucial role in lead adsorption. Lead adsorptive capability of sea nodule is practically destroyed when calcined at a temperature of 900 degrees C. Lead loading capacity of sea nodule has been estimated at 440 mg of lead per gram of sea nodule. The performance of sea nodule as a lead adsorbent has been successfully tested over six simulated lead contaminated water systems. Lead loading capacity of sea nodule compares favorably with other adsorbents like activated carbon, ion exchange resin, anionic clay, granulated blast furnace slag and natural and treated zeolites.

Adsorption↗

PubMed2003

A Lotus japonicus beta-type carbonic anhydrase gene expression pattern suggests distinct physiological roles during nodule development.

A full-length cDNA clone, designated Ljca1, coding for a beta-type carbonic anhydrase (CA; EC: 4.2.1.1) was isolated from a Lotus japonicus nodule cDNA library. Semi-quantitative RT-PCR analysis revealed that Ljca1 codes for a nodule-specific CA, transcripts of which accumulate at maximum levels in young nodules at 14 days post-infection (d.p.i.). In situ hybridization and immunolocalization revealed that Ljca1 transcripts and LjCA1 polypeptides were present at high levels in all cell types of young nodules. In contrast, in mature nodules both transcripts and polypeptides were confined in a few cell layers of the nodules inner cortex. However, the central infected tissue of both young and mature nodules exhibited high CA activity, indicating the presence of additional CA isoforms of plant and/or microbial origin. This was supported by the finding that a putative Mesorhizobium loti CA gene was transiently expressed during nodule development. In addition, the temporal and spatial accumulation of phosphoenolpyruvate carboxylase (PEPC; EC: 4.1.1.31) was determined by semi-quantitative RT-PCR and immunolocalization. The results suggest that LjCA1 might fulfill different physiological needs during L. japonicus nodule development.

Amino Acid Sequence↗

PubMed2001

Identification of small lung nodules at autopsy: implications for lung cancer screening and overdiagnosis bias.

PURPOSE: Unsuspected cases of lung cancer are reported to be uncommon in autopsy series, and these data have been used to suggest that indolent tumors are rare and that overdiagnosis bias is not an important factor in lung cancer screening. The purpose of this study was to determine if a retrospective autopsy review is indeed accurate in identifying all small lung nodules on CT, and thus provide a true estimate of unsuspected lung tumors. MATERIALS AND METHODS: We identified all 1047 patients who had an autopsy at our institution from 1994 to 1998. We then reviewed the patients radiology records and found 187 patients with a thoracic CT within 2 months of the postmortem examination. All 187 CT reports were reviewed in order to identify patients with at least one pulmonary nodule. CT studies with reports that described a nodule(s) were then re-reviewed to confirm presence and location of the nodule(s). The CT findings were than compared to the autopsy report to determine if the postmortem examination indeed found the nodule(s). RESULTS: 28 autopsy patients had at least one pulmonary nodule identified on their thoracic CT no more than 2 months before death. Nineteen patients (68%) had nodule(s) recorded on the autopsy report, two ( approximately 10%) of which proved to have undiagnosed squamous cell carcinoma. Nine patients (22%) had no mention of pulmonary nodules seen on the CT recorded on their autopsy report. CONCLUSIONS: This study suggests autopsies do not identify all small pulmonary nodules found at CT. The true incidence of clinically insignificant lung cancer is thus uncertain, and overdiagnosis bias in lung cancer screening may be more important than previously recognized.

Adult↗