Arguments for a histogenetic classification of lung carcinomas

Taking into consideration the common origin of lung carcinomas from the basal-intermediate cells of covering epithelia of bronchi and bronchioles (which have preserved their ability to divide and differentiate under different stimuli), and the development of tumors in at least two phases, the main histogenetic characteristics of lung carcinomas are discussed. There are pointed out the various and multiple promoting factors acting at the level of proliferating cell foci resulted from the initiating action of chemical carcinogens and the varied deepness of the cellular changes induced. Under these conditions, the malignantly transformed cells may remain poorly differentiated, like during the histogenesis of macrocellular carcinomas (which might be influenced in the course of proliferation, within some limits, by active factors), they may preserve the stereotype of cylindrocubic development, like during the formation of cylindrocubic carcinomas (bronchiolo-alveolar cell carcinomas included), or may suffer metaplastic changes and form subsequently epidermoid carcinomas; the inclusion of Kultschitzky-APUD cells within proliferating foci may lead to bronchial carcinoids or to microcellular carcinomas. The particular forms of lung carcinomas (giant celled, adenocystic, mucoepidermoid) histogenetically reflect the mixed or concomitant stereotypical evolutions of basal cells while preserving some secretory possibilities.     

Ultrastructure of macrocellular (large cell) carcinomas of the lung

The electronmicroscopic investigation of five lung tumors histodiagnosed as macrocellular carcinomas showed the ultrastructural monomorphism of large, variedly shaped neoplastic cells, lack of intercellular junctions, voluminous nuclei with many indentations of nuclear membrane, dispersed euchromatin, large and multiple nucleoli, and nuclear bodies. A reduced number of cytoplasmic organelles was characteristic for these cells, represented mainly by mitochondria, rare rough endoplasmic reticulum, free ribosomes rare Golgi vesicles and flattened tubules, and a various amount of tonofilaments. These features characterized the poorly differentiated proliferation forming these tumors. The elements of differential diagnosis from other poorly differentiated lung tumors (epidermoid and cylindrocubic) are discussed, allowing the consideration of this proliferation type with repressed differentiation and maturation as a real one in the framework of lung carcinomas.     

Diagnosis and typing of lung carcinomas by cytopathologic methods. A review of 108 cases

A correlative review was made of the type of cytology specimens (sputum, bronchial washing and bronchial brushing) together with the corresponding histopathologic specimens of 108 patients. One hundred patients had primary pulmonary carcinomas diagnosed histopathologically (84) or clinically (16); 5 had carcinomas metastatic to the lungs and 3 had apparently false-positive cytologic results for lung cancer. The correlative review was used to determine the diagnostic reliability of pulmonary cytopathologic techniques in the detection and classification of lung carcinomas (i.e., the sensitivity and accuracy). The overall sensitivities of sputum, bronchial washing and bronchial brushing cytology were 60%, 66% and 77%, respectively (p less than 0.05). Bronchial brushing had a higher sensitivity (80%) for peripheral and metastatic lesions than did sputum (37%) or bronchial washing (60%). The overall accuracies of sputum, bronchial washing and bronchial brushing cytology were 79%, 75% and 76%, respectively, which is not statistically different. Regardless of the sampling methods, cytologic typing of squamous-cell and small-cell carcinomas was highly accurate but was less satisfactory for the other types of lung carcinomas. In the 16 cases in which endoscopic biopsies were either not attempted or gave negative results, one or more pulmonary cytologic specimens showed malignant cells. It is concluded that: (1) pulmonary cytopathologic techniques have excellent sensitivity and accuracy in the diagnosis of lung carcinomas; (2) they may establish the diagnosis of pulmonary carcinomas when endoscopic biopsies give negative results; and (3) they are particularly helpful in cases in which endoscopic biopsies suffer from a low yield (peripheral lesions) or create a considerable danger to the patients (iatrogenic hemorrhage).     

Giant cell carcinoma of the lung. A quantitative and histogenetic analysis of eight new cases

An analysis of the so-called giant cell carcinoma of the lung was performed in the light of eight new cases (five macrocellular and three cylindrocubic carcinomas) with different proportions of giant cells, and of a quantitative study of giant cells within the structure of 60 lung carcinomas, fifteen of each basic type of proliferation. Taking into account these data and those of the literature, it was concluded that giant cell carcinomas do not form either a basic type or a variant (subtype) of one of the lung carcinoma types, as suggested by WHO's typing (macrocellular). They represent, in author's conception, only particular forms of neoplastic proliferation in the lung, in which special conditions arising during the prolonged promotion phase influence mitosis, differentiation and/or maturation and modulation of cells composing the proliferating neoplastic foci. The large variations in the amount of giant cells also reflect these intervening actions.     

Chromium content of normal and pathologically altered lung tissue

Flameless atomic absorption spectrophotometry was used to determine the chromium (Cr) content of samples taken at autopsy from the lungs, bronchi, and regional hilar lymph nodes of 50 randomly selected patients from urban and rural areas; these patients were not known to have been excessively exposed to Cr. On the average, the Cr concentration in the lungs of patients younger than 40 yr of age was approximately 2 μg/g; for patients over 40, the average Cr values were between 5 and 15 μg/g dry wt. The highest values were found in samples from the apex of the lung. The Cr concentration in lung and lymph nodes increased in proportion to age and the degree of anthracosis. Chromium content in the bronchial wall was very low in all cases. Chromium values up to ten times greater as compared to age-matched average values were found in scarred lung tissue, probably caused by a postinflammatory lymph vessel blockade. Slightly elevated Cr values were found in smokers' lungs. Chromium values in tissue from primary lung carcinomas (n=9) were lower than those in neighboring lung tissue. Based on the results of this study the amount of Cr of lung and bronchial tissue does not appear to be associated with the induction of bronchial carcinoma.     

Determining deposition sites of inhaled lung particles and their effect on clearance

An essential component of lung defense is clearance of particulates and infectious vectors from the mucus membrane of the tracheobronchial tree and the alveolar regions of the lung. To partition clearance between these areas we determined the bronchial branching pattern, the anatomical sites of particle deposition, and subsequent clearance in the same animal. Using a 2.85-microns particle tagged with 57Co for inhalation and deposition in the sheep lung, we followed clearance via a series of computer-stored gamma-scintillation lung images. The same sheep was reinhaled, and the particle distributions for both inhalations were compared. After the animals were killed, the bronchial branching pattern and length of the bronchial tree were documented. The number of particles depositing in all bronchi down to 1 mm diam was determined by scintillation counting, and the number in respiratory bronchioles and alveoli was microscopically counted. We conclude that particles deposited in bronchi greater than or equal to 1 mm diam clear in 2-4 h postdeposition. Bronchi distal to 1-mm-diam bronchi and alveoli clear evenly over 72 h, and the number of particles equal to the tracheobronchial deposition cleared after 45 h.     

Flow cytometric measurement of p53 protein expression and DNA content in paraffin-embedded tissue from bronchial carcinomas

The nuclear protein p53 has been measured in archival lung cancer biopsies. The monoclonal antibody PAb 1801, which recognizes human p53, was used. After immunostaining, the nuclei prepared from paraffin-embedded tissue were stained with propidium iodide for simultaneous measurement of DNA content; 17 of 24 lung cancers were p53 positive. The S-phase fraction in positive tumors was 22.9 +/- 6.4%, as compared to 13.6 +/- 6.1% in negative tumors (P less than 0.02). In ten of the positive tumors (two small cell carcinomas and eight non-small cell carcinomas), the p53 expression varied through cell cycle, whereas in seven tumors (five small cell carcinomas and two non-small cell carcinomas), no such variation of p53 expression was observed. Freezing the nuclear suspensions did not substantially reduce the p53 signals. Control experiments with the SV40-transformed human foreskin fibroblast cell line HSF4-T12 showed that the enzymatic digestion utilized to dissociate paraffin-embedded tissue did not significantly reduce p53 fluorescence. Immunohistochemical staining of biopsy specimens indicated that only cancer cells were overexpressing p53. In conclusion, using the monoclonal antibody PAb 1801, p53 is detectable in cell nuclei prepared from paraffin-embedded bronchial carcinoma biopsies. P53 positive tumors have increased proliferative activity compared to p53 negative tumors. Furthermore, the lack of cell cycle variation of p53 in small cell carcinomas indicates that this pattern may be related to high-grade malignancy.     

Lung pathogenesis. V. The stereotype development of bronchial and lobular pathological reactions (a systemic approach)

Taking into account the present data upon the general stereotyping of different pathological processes of various nature challenged by the extremely numerous environmental actions, a structural analysis of the peculiarities presented by such reactions at the lung level, mainly on bronchial and lobular structures, was attempted. It was shown that the first damaged structures and their behaviour impose the peculiarities of the subsequently developed reactions which manifest a certain stereotyping, different when bronchi or lobules are the first lesioned. Relationships between bronchial and lobular lesions were also analysed and pointed out their role in the development of the whole complex process of the lung. This special aspect of lung complex pathogenesis was also emphasized.     

SELF-HEALING PSEUDOCANCERS OF THE SKIN

It is believed that a group of self-healing tumors which clinically and microscopically may be confused with squamous cell carcinomas are all variants of one entity, although there are certain differences between the members of the group. The clinical, as well as the histologic evaluation of these tumors is necessary to differentiate them from true squamous cell carcinomas. Some should be treated for cosmetic purposes since the scars following self-healing may be more unsightly than those caused by treatment.     

Extravascular sources of lung angiotensin peptide synthesis in idiopathic pulmonary fibrosis

Previous work from this laboratory demonstrated de novo synthesis of angiotensin (ANG) peptides by apoptotic pulmonary alveolar epithelial cells (AEC) and by lung myofibroblasts in vitro and in bleomycin-treated rats. To determine whether these same cell types also synthesize ANG peptides de novo within the fibrotic human lung in situ, we subjected paraffin sections of normal and fibrotic (idiopathic pulmonary fibrosis, IPF) human lung to immunohistochemistry (IHC) and in situ hybridization to detect ANG peptides and angiotensinogen (AGT) mRNA. These were analyzed both alone and in combination with cell-specific markers of AEC [monoclonal antibody (MAb) MNF-116] and myofibroblasts [alpha-smooth muscle actin (alpha-SMA) MAb] and an in situ DNA end labeling (ISEL) method to detect apoptosis. In normal human lung, IHC detected AGT protein in smooth muscle underlying normal bronchi and vessels, but not elsewhere. Real-time RT-PCR and Western blotting revealed that AGT mRNA and protein were 21-fold and 3.6-fold more abundant, respectively, in IPF lung biopsies relative to biopsies of normal human lung (both P < 0.05). In IPF lung, both AGT protein and mRNA were detected in AEC that double-labeled with MAb MNF-116 and with ISEL, suggesting AGT expression by apoptotic epithelia in situ. AGT protein and mRNA also colocalized to myofibroblast foci detected by alpha-SMA MAb, but AGT mRNA was not detected in smooth muscle. These data are consistent with earlier data from isolated human lung cells in vitro and bleomycin-induced rat lung fibrosis models, and they suggest that apoptotic AEC and myofibroblasts constitute key sources of locally derived ANG peptides in the IPF lung.     

Dry mass, DNA and non-histone protein determinations in lung cancer cells

Summary Cell nuclei from two biopsies of bronchial mucosa, seven squamous-cell carcinomas and six small-cell carcinomas of the lung were investigated. DNA and non-histone protein (NHP) content were simultaneously determined in Feulgen—Naphthol Yellow S-stained smears by means of multiple plug cytophotometry. In addition, the nuclear dry mass of cells originating from the same populations was measured by interference microscopy.DNA histograms of carcinomas were characterized by DNA stemlines being situated in the diploid range in four out of six small-cell carcinomas and in the hyperdiploid to hypertetraploid range in six out of seven squamous-cell carcinomas.Polyploid values (up to 8 c) were seldom found in small-cell carcinomas whereas squamous-cell carcinomas showed a broader dispersion approaching the 16 c level.The similarity of the NHP distributions with the DNA histograms was more marked in small-cell carcinomas than in the squamous-cell carcinomas. In comparison with the NHP distributions of normal bronchial epithelial cells, those of carcinomas were shifted to higher values. The increased NHP content was found to be a more prominent sign of malignancy in small-cell carcinomas than the DNA mass. The increase in nuclear dry mass in carcinomas was mainly caused by the accumulation of NHP in tumour cell nuclei.     

Diagnostic significance of flow cytometric DNA analysis applied for the detection of cancer cells in bronchial washing fluid

Since both DNA aneuploidy and increased proliferative activity are important characteristics of malignant neoplasms, flow cytometric (FCM) analysis was used to examine the cell content in bronchial washing samples obtained via fiberoptic bronchoscopy from 73 patients. The results were compared with the results of histology and conventional cytology. The patients included 30 with bronchial carcinomas, 12 with bronchopneumonia and 31 with no evidence of lung disease. Of the 30 patients with histologically confirmed lung cancers, 25 showed either aneuploid stem lines (19 cases) or high levels of proliferation (6 cases) as determined by analysis of cell-cycle stages. The same rate of cancer cell detection was obtained by cytology. In the 43 cases with neither histologic nor clinical evidence of malignancy, FCM data yielded 5 false-positive results, as compared to 4 erroneous suspicions of cancer by cytology. From these data, it is concluded that FCM measurements of both DNA ploidy and proliferative activity may complement conventional cytology in the recognition of bronchial carcinomas.     

Eosinophilic granulomas of the lung. Histopathology of three cases

Three cases of eosinophilic granuloma of the lung were histopathologically analyzed on surgical materials (two resections and lung biopsy). The analysis insisted upon the cell components of pulmonary lesions, histiocytic and eosinocytic accumulations involving lobular air spaces, alveolar walls and interlobular areas, and forming bullae by histiocytic enzymic activity and lipid dysmetabolism; the fibrotic evolution of the lesions varied from case to case. The lesional histogenesis is discussed in the light of recent electronmicroscropic, histochemical and immunopathological data, stress being laid upon the local influence on the development of the process.     

Sputum cytology of metastatic carcinoma of the lung.

The cytopathology of 47 cases of metastatic carcinoma of the lung and of 28 cases of recurrent or metastatic bronchogenic carcinoma is reviewed. The diagnostic yield was better for recurrent than for metastatic carcinoma but overall was comparable to that of primary bronchogenic carcinomas. The metastatic tumors were located in all areas of the lung and included single as well as multiple lesions. The positive yield did not differ significantly in relation to any of the pathologic features but was somewhat higher if the metastases were large and centrally located. A definite differentiation of the metastatic tumors, usually adenocarcinomas, from new primary bronchogenic carcinomas is often possible particularly if the cytopathology can be compared with that of the primary lesion. Specific cytologic features include the relative lack of cohesion and the formation of columns in metastatic breast carcinomas, the formation of larger cohesive well circumscribed nodules composed of tall columnar cells in metastatic colon carcinomas, clear cell features in some metastatic adenocarcinomas of the kidney, and the small cell size and uniform, regular nuclear features in the often cytologically well differentiated metastatic carcinomas of the prostate.     

BRONCHIAL CARCINOMA—Lobar Distribution of Lesions in 250 Cases

In a study of the lobar distribution of tumors in 250 consecutive cases of primary bronchial cancer, it was noted that 130 of the tumors originated in the upper lobes, 11 in the right middle lobe, and 49 in the lower lobes. Some 40 arose in the main bronchi, and most of the remainder were either “hilar” or unspecified in anatomic location.There was no apparent correlation of the lobar site of these tumors with the lobar location of childhood pneumonic lesions as observed in another group of patients in the same hospital.     

Pharmacological factors influencing permeability of the bronchial microcirculation.

The bronchial microcirculation is organized as a network of interconnected superficial and deep small blood vessels that extend throughout the bronchial tree. The close proximity of the bronchial venules to the origin of the pulmonary lymphatics suggests a role in fluid balance in the lung. The responsiveness of the venous segment of this network to agents influencing permeability clearly indicates a role in the genesis of certain types of noncardiogenic interstitial edema. The responsiveness of the venous segment of the bronchial circulation to neural and humoral stimuli raises the possibility of a significant role in the distribution of blood flow between the mucosa and peribronchial space. Such control may play a significant role in heat and water exchange between blood and air. Thus, these observations indicate that the bronchial microcirculation is involved with aspects of pulmonary function other than the nutrition of the bronchi, nerves, pleura, and large pulmonary blood vessels.     

Calcitonin gene-related peptide and the lung: neuronal coexistence with substance P, release by capsaicin and vasodilatory effect

The occurrence and distribution of calcitonin gene-related peptide (CGRP) in the lower airways was studied by means of immunohistochemistry and radioimmunoassay (RIA) in combination with high performance liquid chromatography (HPLC). CGRP-like immunoreactivity (-LI) was observed in nerves from the epiglottis down to peripheral bronchi in rat, cat and guinea pig and also in human bronchi. Double staining revealed colocalization of CGRP-LI and substance P (SP)-LI in cell bodies of nodose and jugular ganglia as well as in axons and nerve terminals of the airways. Systemic capsaicin pretreatment induced a marked loss of the CGRP- and SP-immunoreactive (-IR) nerves in the lower airways. CGRP-IR was also present in epithelial endocrine cells and neuroepithelial bodies. The content of CGRP-LI as measured with RIA in guinea pig bronchi was significantly lower after capsaicin pretreatment. Analysis of human bronchial extracts revealed that CGRP-LI coeluted with synthetic human CGRP on HPLC. In the isolated perfused guinea pig lung capsaicin exposure caused overflow of CGRP-LI suggesting release from peripheral branches of sensory nerves. Both in vivo experiments in the guinea pig measuring insufflation pressure as well as in vitro studies on isolated guinea pig and human bronchi showed that whereas tachykinins contracted bronchial smooth muscle no contractile or relaxing effect was elicited by human or rat CGRP. However, CGRP caused relaxation of serotonin precontracted guinea pig and human pulmonary arteries. In conclusion, the presence and release of CGRP-LI from capsaicin sensitive nerves in the lower airways adds another possible mediator, in addition to tachykinins, of vascular reactions upon sensory nerve irritation.     

Diagnosis of bronchial carcinoma on sections of paraffin-embedded sputum. Sensitivity and specificity of an alternative to routine cytology.

The diagnostic accuracy of sputum cytology for the diagnosis of bronchial carcinoma using paraffin-embedded, serially sectioned and hematoxylin and eosin-stained specimens was tested in 4,297 sputum samples from 1,889 patients, 219 of whom had bronchial carcinoma. The diagnostic sensitivity depended mainly on the number of investigated samples and was 85.4% with three sufficient sputa. The sensitivity was not influenced by the histologic types, location or TNM stage of the tumor. The specificity of the method was 99.5%. In three cases localization of sputum cytologically diagnosed bronchial carcinomas was not possible immediately (occult carcinomas, pTx); in two of these cases the bronchial carcinomas were located during follow-up. The third patient died without verification of the cytologic diagnosis. According to our results, sputum cytology on serial sections is a valuable instrument for mass screening of high-risk groups for the early detection of bronchial carcinoma. Lower sensitivities of sputum cytology in mass screening programs for the early diagnosis of lung cancer are discussed critically.     

Frequent HIN-1 promoter methylation and lack of expression in multiple human tumor types

HIN-1 (high in normal-1) is a candidate tumor suppressor identified as a gene silenced by methylation in the majority of breast carcinomas. HIN-1 is highly expressed in the mammary gland, trachea, lung, prostate, pancreas, and salivary gland, and in the lung, its expression is primarily restricted to bronchial epithelial cells. In this report, we show that, correlating with the secretory nature of HIN-1, high levels of HIN-1 protein are detected in bronchial lavage, saliva, plasma, and serum. To determine if, similar to breast carcinomas, HIN-1 is also silenced in tumors originating from other organs with high HIN-1 expression, we analyzed its expression and promoter methylation status in lung, prostate, and pancreatic carcinomas. Nearly all prostate and a significant fraction of lung and pancreatic carcinomas showed HIN-1 hypermethylation, and the majority of lung and prostate tumors lacked HIN-1 expression. In lung carcinomas, the degree of HIN-1 methylation differed among tumor subtypes (P = 0.02), with the highest level of HIN-1 methylation observed in squamous cell carcinomas and the lowest in small cell lung cancer. In lung adenocarcinomas, the expression of HIN-1 correlated with cellular differentiation status. Hypermethylation of the HIN-1 promoter was also frequently observed in normal tissue adjacent to tumors but not in normal tissue from noncancer patients, implying that HIN-1 promoter methylation may be a marker of premalignant changes. Thus, silencing of HIN-1 expression and methylation of its promoter occurs in multiple human cancer types, suggesting that elimination of HIN-1 function may contribute to several forms of epithelial tumorigenesis.     

Nuclear DNA in histologic sections from squamous-cell carcinoma and adenocarcinoma of the lung

The nuclear DNA content in morphologically identified tumor cells was analyzed in 4-micron histologic sections from 58 patients with lung carcinoma who survived for at least five years. Thirty-three of the carcinomas were invasive squamous bronchial carcinomas and 25 were pulmonary adenocarcinomas. In all squamous carcinomas, the majority of tumor cells were found to exhibit DNA values exceeding the normal tetraploid and/or diploid region. In contrast, some of the pulmonary adenocarcinomas were found to be composed of a majority of tumor cells with DNA values in the normal diploid region. The results indicate that invasive squamous bronchial carcinomas, in general, are tumors with aneuploid DNA patterns indicative of a high malignant potential and that malignancy grading based on DNA measurements does not add any significant prognostic information to that obtained by morphologic diagnosis.