Neural cell adhesion molecules (NCAM) and NCAM-PSA expression in neuroendocrine lung tumors

Neural cell adhesion molecules (NCAM) represent specific markers of neuroendocrine (NE) differentiation in lung cancer. Because the polysialic acid form (NCAM-PSA) has reduced adhesion properties, we hypothesized that NCAM-PSA expression could favor metastatic spread. Immunostaining of NCAM and NCAM-PSA were therefore compared in 120 NE lung tumors, including 17 typical carcinoids, 3 atypical carcinoids, 30 large cell NE carcinomas and 70 small cell lung carcinomas, as compared with 25 adenocarcinomas and 25 squamous cell carcinomas. Neural cell adhesion molecules were negative in adenocarcinomas and squamous cell carcinomas but were constantly expressed in all NE tumors from typical carcinoids to small cell lung carcinomas. NCAM-PSA expression was significantly more frequent in high-grade tumors, with 24 of 30 positive cases in large cell NE carcinomas and 65 of 70 positive cases in small cell lung carcinoma, than in carcinoids with 10 of 17 and 2 of 3 positive cases in typical carcinoids and atypical carcinoids, respectively. The neural cell adhesion molecule-polysialic acid form scores of staining were significantly higher in high-grade as compared with low-grade tumors (p = 0.002), and were correlated with nodal spread (p = 0.04) and metastasis (p = 0.016) across histologic classes but not in individual tumor type. We conclude that NCAM-PSA connotes poor differentiation and aggressive clinical behavior in the spectrum of NE lung tumors, but cannot be regarded as a prognostic factor in individual tumor classes.     

Apoptosis-related factors p53, Bcl2, and Bax in neuroendocrine lung tumors

Neuroendocrine (NE) lung tumors comprise four classes of progressive aggressiveness for which proliferation and apoptosis rates could both contribute to their distinctive behavior. As p53 mutations may favor escape from apoptosis through changes in Bcl2-Bax expression balance, which are survival and apoptotic genes, respectively, we studied 121 NE lung tumors (16 typical carcinoids (TC), 5 atypical carcinoids (AC), 29 large-cell NE carcinomas (LCNECs), and 71 small-cell lung carcinomas (SCLCs) using immunohistochemistry. We quantified apoptosis by terminal-deoxynucleotidyl-transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) in 31 of these cases. There was a significant increase of p53 mutant immunophenotype (defined as immunoreactivity with at least two antibodies for at least 20% of tumor cells) between atypical/typical carcinoids group and the LCNEC/SCLC group (P = 0.0003). There was an inverse correlation (P < 0.0001) between the scores of Bax and Bcl2 expression in individual tumors and a significant inversion of the Bcl2. Bax ratio between low-grade (typical and atypical carcinoids) and high-grade (LCNECs and SCLCs) tumors with a predominant Bax expression in the first group and predominant Bcl2 expression in the second. Whereas carcinoids had variable apoptotic indexes, LCNECs had high indexes (1.3 to 6.8%), Bcl2 overexpression, Bax down-regulation, and Bcl2.Bax ratio > 1 correlated with lower apoptotic index in both LCNEC and the pool of LCNECs and SCLCs (P < 0.05) and a lower survival rate in the group of atypical and typical carcinoids and LCNECs (P < 0.002). The highest levels of Bcl2 expression and Bcl2.Bax ratios were associated with p53 mutant immunophenotype (P = 0.02). Our results suggest that aggressiveness in NE lung tumors could be linked, in addition to proliferation, to apoptosis-related factors.     

Primary, pure, large-cell neuroendocrine carcinoma of the urinary bladder

We report what to our knowledge is the first case in the English-language literature of a primary, pure, undifferentiated large-cell neuroendocrine carcinoma of the urinary bladder. To date, only one case of a large-cell neuroendocrine carcinoma was reported, and it was associated with an adenocarcinoma most likely of urachal origin. On the other hand, slightly more than 100 cases of undifferentiated small-cell carcinoma of the urinary bladder were reported, approximately one-half of which were associated with poorly differentiated transitional-cell carcinoma of the conventional type. The patient in our case was a 73-year-old man with a history of prostatic cancer treated with radiation therapy. He presented with hematuria, leading to the discovery of a solitary tumor on the dorsal wall of the urinary bladder. A diagnosis of large-cell neuroendocrine carcinoma was made, supported by immunohistochemical reactivity for chromogranin, neuron-specific enolase, and synaptophysin; a variety of other hormonal markers of neuroendocrine tumors were negative. The radical cystoprostatectomy and bilateral pelvic lymphadenectomy specimen showed a transmurally invasive tumor, without regional lymph node metastases. The patient died 2 months after surgery, and the autopsy revealed disseminated metastases histologically identical to the urinary bladder neoplasm. Awareness of the occurrence of large-cell neuroendocrine carcinoma of the urinary bladder seems to be important because of the possible aggressive outcome associated with this tumor and because of differential diagnostic considerations, which include malignant lymphoma and metastasis from another primary, especially in tumors occurring in a pure form.     

Unbalanced chromosomal aberrations in neuroendocrine lung tumors as detected by comparative genomic hybridization

Typical and atypical carcinoids (TC, ATC) and small (SCLC) and large cell neuroendocrine carcinomas (LCNEC) constitute the spectrum of neuroendocrine lung tumors. Chromosomal aberrations have not been studied in LCNEC and only rarely in carcinoids. Only SCLCs have been investigated frequently for chromosomal aberrations. We compared three typical and four atypical carcinoids, one atypical carcinoid/SCLC mixed type, three SCLC, and three LCNEC for chromosomal gains and losses using comparative genomic hybridization. Typical carcinoids showed either no changes or only few chromosomal gains. Atypical carcinoids appeared genetically heterogeneous: One case had no aberrations, and three cases had few aberrations; two of them showed a deletion of 11q. SCLC and LCNEC were characterized by many gains and losses, especially similar changes of 3p, 5q, 5p, and 13q. Although ATC resemble LCNEC morphologically, there were no similarities at the genetic level. We have found a reciprocal relationship of prognosis and the amount of aberrations. TCs and ATCs with few chromosomal changes have the best prognosis, whereas SCLCs and LCNECs were generally characterized by a great amount of aberrations and worst prognosis. There was no unbalanced aberration common in all types of neuroendocrine tumors of the lung.     

CD45 (leukocyte common antigen) immunoreactivity in metastatic undifferentiated and neuroendocrine carcinoma: a potential diagnostic pitfall

Leukocyte common antigen (CD45/LCA) and keratin expression are generally mutually exclusive in diagnostic surgical pathology. CD45 reactivity is a reliable indicator of the hematolymphoid nature of a tumor, whereas keratin reactivity is typical of epithelial differentiation (carcinomas and some sarcomas). Some lymphomas, however, might lack detectable CD45 expression, whereas occasional ones might express keratins. CD45 immunoreactivity has been considered exquisitely specific for hematopoietic cells. We report three undifferentiated or neuroendocrine carcinomas that showed membrane-associated immunoreactivity for CD45 in addition to showing distinctive keratin cocktail (AE1/AE3) and epithelial membrane antigen reactivity (all cases); also, keratin 7 was demonstrated in one case and keratin 19 in another. Two cases were lymph node metastases of undifferentiated carcinomas, one of them from the lungs and the other of an unknown origin; the former case showed neuroendocrine features. The third case represented a pulmonary large-cell undifferentiated carcinoma. These cases were negative for lineage-specific leukocyte antigens and did not show clonal immunoglobulin heavy-chain gene rearrangements. Electron microscopic studies demonstrated desmosomes and keratin-like tonofilaments in all three cases, thus confirming the epithelial nature of these tumors. The exceptional membrane staining for CD45 seen in these undifferentiated carcinomas might be comparable to experimentally detected incorporation of leukocyte antigens into the cell membranes of nonleukocytic cells in a leukocyte-rich environment. This rare diagnostic pitfall should be considered in the diagnostic surgical pathology of undifferentiated tumors. It is best avoided by employing a panel of leukocyte and epithelial antigens and by use of electron microscopy, if possible.     

Lymphocytes in host defense against Pneumocystis carinii

To determine the neuroendocrine (NE) features of thymic epithelial tumor, immunohistochemistry and electron microscopy studies were performed on eight NE tumors (thymic carcinoids) and 26 non-NE tumors (nine thymic carcinomas, five atypical thymomas, and 12 thymomas other than lymphocytic thymoma). Immunohistochemical studies were performed with antibodies against general markers for NE cells (synaptophysin, alpha subunit of a guanine nucleotide-binding protein, Go, and small-cell lung carcinoma cluster 1 antigen), and a broad panel of antibodies for hormonal substances. Thymic carcinoid showed synchronous diffuse immunoreactivity for the three NE markers and contained cells that were positive for a variety of hormonal products: human chorionic gonadotropin (hCG) alpha-subunit (eight of eight), hCG beta-subunit (three of eight), adrenocorticotropic hormone (ACTH) (three of eight), calcitonin (two of eight), calcitonin gene-related peptide (two of eight), and serotonin (one of eight). Conversely, although positivity for NE markers was neither synchronous nor diffuse in non-NE tumors, seven of nine thymic carcinomas, three of five atypical thymomas (focal or dispersed distribution), and none of the five thymomas were positive for at least two of these NE markers. A small number of neoplastic cells were positive for hCGalpha-subunit or ACTH in three thymic carcinomas and one atypical thymoma. Ultrastructurally, dense core granules (DCG) were much more frequent in thymic carcinoid, but several DCG-like granules were identified in 12 of 13 non-NE tumors with or without immunoexpression of NE markers. The presence of focal or dispersed NE cells in thymic carcinoma and atypical thymoma may reflect multidirectional differentiation within the tumor, which, like cytological atypia, epithelial CD5 expression, and lack of immature T cell infiltration, may be another feature of this group at thymic tumors.     

Neuroendocrine carcinomas of the larynx

Neuroendocrine carcinomas of the larynx are uncommon tumors. They include typical carcinoid tumors, atypical carcinoid tumors and small cell neuroendocrine carcinomas. The diagnosis is based on light microscopy which demonstrate evidence of neurosecretory granules, and on histochemical and immunohistochemical investigations. The histogenesis, treatment and prognosis factors are discussed.     

Genotator: a workbench for sequence annotation

The clinical, pathological, and immunohistochemical features of six cases of metastatic neuroendocrine and carcinoid tumors to the thyroid simulating medullary thyroid carcinoma (MTC) are described. The patients were women between the ages of 24 and 70 years who, without symptoms or significant past medical histories, presented with either a single mass or multiple thyroid nodules. The primary source of the tumor was only discovered on follow-up. Two of the neoplasms were classical carcinoid tumors, one was a carcinoid predominantly composed of large cells, another showed a prominent oval to spindle cell component, and the two remaining cases were atypical carcinoid/high-grade neuroendocrine carcinomas. The immunohistochemical profile was inconsistent with MTC in that all tumors were negative for calcitonin and only two were focally positive for carcinoembryonic antigen (CEA). A variable pattern of staining for other neuroendocrine and epithelial markers was obtained in each case. Despite the morphologic and immunohistochemical similarities with MTC, the diagnosis of a metastatic neuroendocrine tumor to the thyroid should be favored in the presence of a predominantly interstitial pattern of spread; occurrence of multiple tumor foci; folliculotropism; rosette formations with lumen and cuticular borders; and lack of immunoreactivity for calcitonin and CEA. The differential diagnosis between MTC and metastatic neuroendocrine carcinoma to the thyroid is of importance because of the vast differences in treatment and prognosis.     

The expression of keratins, vimentin, neurofilament proteins, smooth muscle actin, neuron-specific enolase, and synaptophysin in tumors of the specific glands in the canine anal region

Eight canine tumors originating from specific glandular structures in the anal region, as well as metastatic tumor tissue of two of these cases (case Nos. 7, 8), were immunohistochemically analyzed using various monoclonal antibodies (MoAbs) directed against human keratin types, vimentin, neurofilament proteins, and alpha-smooth muscle actin. These tumors also were stained for the broad-spectrum neuroendocrine markers neuron-specific enolase (NSE) and synaptophysin. In histologically normal canine anal structures, alpha-smooth muscle actin and NSE antibodies stained basally localized (probably myoepithelial) cells in the anal glands and the anal sac glands. NSE staining also was present in a limited number of luminal cells in both anal glands and anal sac glands. Synaptophysin labeling was not observed in any of these glandular structures. Histologically, the tumors were differentiated into well- and moderately differentiated perianal gland tumors (n = 5) and carcinomas without perianal gland differentiation (n = 3), corresponding to the so-called apocrine carcinomas of the anal region. Immunohistochemically, the perianal gland tumors could be differentiated from the carcinomas by marked differences in staining pattern with the various keratin MoAbs, particularly MoAbs directed against human keratin types 7 and 18. The keratin-staining characteristics of the carcinomas suggest a glandular luminal cell origin. Metastases of the carcinomas showed loss of some keratin-staining characteristics as compared with the primary tumor. Staining for NSE was only observed in solitary cells and small cell clusters in the carcinomas and their metastases, whereas the alpha-smooth muscle actin antibody did not react with the carcinoma cells. None of the tumors stained for neurofilament proteins or synaptophysin. An unequivocal neuroendocrine nature of the carcinomas could not be substantiated by our immunohistochemical study, although the presence of a population of neuroendocrine cells within these neoplasms seems likely. Because the immunohistochemical features of the carcinomas with respect to various keratin MoAbs and NSE are similar to those of the anal glands and the anal sac glands, both these glands might be considered as site of origin of these carcinomas.     

Altered retinoblastoma and p53 protein status in non-small cell carcinoma of the lung: potential synergistic effects on prognosis

Routinely processed pathological specimens from 119 patients with stage I and II adenocarcinomas or squamous cell carcinomas were examined by immunohistochemical analysis for altered retinoblastoma (RB) and/or p53 protein expression. Absent RB nuclear staining (RB-) indicating loss of RB function occurred in 19 (16%) of the cases studied, whereas expression of a putative mutant p53 nuclear protein (p53(+)) was found in 54 (45%) of the tumors. The median survival was 39 versus 12 months for patients with RB+ and RB- tumors, respectively (P = 0.05 by log rank analysis). Similarly, the median survival was 41 months for patients whose tumors had no expression of mutant p53 (p53(-)) compared with 24 months for individuals with p53 (+) tumors (P = 0.01). These differences in survival, however, were not statistically significant by multivariate analysis. Nevertheless, individuals with RB-/p53(+) tumors had a significantly shorter median survival (12 months) than those with RB+/p53(-) tumors (41 months), as determined by both log rank and multivariate analyses (P = 0.005 and 0.03, respectively). In addition, 66 large cell carcinomas from all stages were examined. Again, a more significant difference in survival (48 versus 8 months) was found between patients with RB+/p53(-) versus RB-/p53(+) tumors (P = 0. 006). These results suggest that RB and p53 status might be used synergistically as prognostic factors in a subset of non-small cell lung carcinomas.     

Analysis of bcl-2 expression in normal, inflamed, dysplastic nasopharyngeal epithelia, and nasopharyngeal carcinoma: association with p53 expression

Differentiation between benign and malignant adrenocortical neoplasms is made using a combination of clinical and pathologic parameters. Despite these parameters, it is still difficult to predict the biologic potential of some tumors. Forty adrenocortical lesions, including 10 hyperplasias, 10 adenomas, 12 carcinomas and eight metastatic/recurrent adrenocortical carcinomas were studied for the expression of MiB-1, p53, and the retinoblastoma gene product (RB) utilizing immunohistochemical techniques. The mean tumor proliferating fraction (TPF), expressed as the number of MiB-1-positive nuclei per 1,000 tumor cells, was 14.9 in adenomas, 31.5 in hyperplasias, 208.1 in carcinomas and 166.1 in recurrent or metastatic disease. None of the 20 benign lesions had a TPF of > 80, and only one of the 20 malignancies had a TPF of < 80. Nine of the 20 carcinomas were positive for p53. None of the benign lesions were p53 positive. Thirty-nine cases, including benign and malignant ones, were RB positive, and one was uninterpretable. We conclude that prognostic markers can be of great assistance in recognizing adrenocortical carcinomas. High TPF (> 80), as measured by staining with MiB-1, and positive p53 strongly correlate with malignant behavior and therefore may be useful in distinguishing benign from malignant adrenal lesions. Staining for RB does not appear to be a helpful technique.     

Radiolabeled somatostatin analog scintigraphy in oncology and immune diseases: an overview

[111In-DTPA-D-Phe1]-octreotide is a new radiopharmaceutical with a great potential for the visualization of somatostatin receptor-positive tumors, granulomas, and diseases in which activated leukocytes play a role. The overall sensitivity of [111In-DTPA-D-Phe1]-octreotide scintigraphy to localize neuroendocrine tumors is high. In several neuroendocrine tumor types, inclusion of somatostatin receptor imaging in the localization or staging procedure may be very rewarding, either in terms of cost-effectiveness, patient management, or quality of life. In our opinion, this holds true for patients with carcinoids, gastrinomas, paragangliomas, small-cell lung carcinoma, and selected cases of patients with insulinomas. The value of [111In-DTPA-D-Phe1]-octreotide scintigraphy in patients with other tumors, such as breast cancer, malignant lymphomas, or in patients with granulomatous diseases, has to be established.     

Aggressive forms of gastric neuroendocrine tumors in multiple endocrine neoplasia type I

In recent classifications of gastric endocrine tumors, tumors arising in patients with multiple endocrine neoplasia type 1 (MEN-1) are regarded to be regulated by the concomitant hypergastrinemia resulting from to pancreatic or, most commonly, duodenal gastrinomas and to have a benign behavior. In this article, we report on two cases of MEN-1 gastric neuroendocrine tumors having a fatal course. Case 1 was a young male with hyperparathyroidism and Zollinger-Ellison syndrome and with florid development of multiple gastric carcinoids and multiple duodenal gastrinomas. Metastases occurred in the liver, of exclusive gastric origin, in periduodenal lymph nodes, of exclusive duodenal origin, and in perigastric lymph nodes, of mixed origin. The patient died 48 months after diagnosis. Case 2 was an adult female patient with hyperparathyroidism, adrenocortical disorders, and gastric tumors but no hypergastrinemia. The patient died 3 months after tumor diagnosis. At autopsy, the stomach showed multiple benign carcinoids and two independent neuroendocrine carcinomas not reported before in MEN-1 and massively metastatizing to lymph nodes, liver, and peritoneum. Multiple islet cell tumors mostly producing pancreatic polypeptide were found, whereas gastrinomas were seen in neither the pancreas nor the duodenum. Allelic losses at the MEN-1 gene locus in chromosome 11q13, the mechanism responsible for tumor development in MEN-1 syndrome, were demonstrated in the carcinoid tumors of case 1 and in the neuroendocrine carcinoma of case 2. We conclude that gastric neuroendocrine tumors in patients with MEN-1 may have a poor outcome, they have the same genetic mechanism as MEN-1 tumors in other organs, and they may be independent of the trophic effect of hypergastrinemia.     

DNA cytophotometry and prognosis in typical and atypical bronchopulmonary carcinoids. A clinicomorphologic study of 100 neuroendocrine lung tumors

Surgical material obtained from 100 patients with typical carcinoids (TC) and atypical carcinoids (AC) of the lung (including 100 primary, four residual tumors, and four lymph node or distant metastases) was investigated by conventional histology and scanning DNA cytophotometry. Of the 60 TC (96%), 58 exhibited euploid DNA histograms compared with only 20 (50%) of the 40 AC. The morphologic findings were related to the patients' survival (median observation period, 9 years). Statistical analyses disclosed the histologic type of disease (TC versus AC) and the DNA content of tumors (euploid versus aneuploid) to affect prognosis significantly (p < 0.001). Deaths resulting from tumor were exclusively observed among patients with atypical (eight of 40) or DNA aneuploid carcinoids (eight of 22). Six patients were alive with persistent tumor manifestations 3 to 20 years after initial diagnosis, four with DNA diploid primary carcinoids. The presence of lymph node metastases alone was not associated with poor prognosis as long as the primary tumor or the related metastases showed a diploid DNA content. DNA cytophotometry thus might be regarded as an adjunctive prognostic criterion in individual carcinoid cases.     

Role of Mycoplasma pneumoniae in acute respiratory-tract infections in Saudi paediatric patients

The expression of RB and bcl-2 proteins was investigated in 135 thyroid carcinomas (130 papillary carcinomas and five follicular carcinomas) by the immunohistochemical technique with RB and bcl-2 monoclonal antibodies. The results were as follows: 1) RB protein nuclear staining was shown in 117 of the 135 thyroid carcinomas (87%). Bcl-2 protein staining was shown in 82 of the carcinomas (61%). 2) There was a higher incidence of recurrence in RB-negative cases than in RB-positive cases (chi 2 test p = 0.001). But there is no significant relationship between the incidence of recurrence and the results of bcl-2 staining (chi 2 test p = 0.287). 3) The expression of RB protein was related to age and clinical N and M categories. Bcl-2 protein expression was related to clinical T categories. 4) The 10-year overall survival rate for RB-positive patients was higher than that for negative patients (long-rank test p < 0.0001). But the survival rate was not associated with bcl-2 expression (log-rank test p = 0.3). Our results suggest that assessment of RB protein expression by the immunohistochemical technique may be useful to determine the possibility of recurrence and to predict the outcome of thyroid carcinomas. We think that assessment of RB protein expression by the immunohistochemical technique can be applied as a more sensitive prognostic factor.     

Quantitation of endopeptidase 24.11 and endopeptidase 24.15 in human blood leukocytes

In order to know the involvement of multiple gene alterations in the pathogenesis of human lung cancer, we examined the genes of K-, H-ras (codons 12, 13, 61), p53(exons 5-9) and the retinoblastoma susceptibility gene (RB)(exons 20-22) using the polymerase chain reaction/single-strand conformation polymorphism method in 32 human lung cancer cell lines (5 squamous-cell carcinomas, 10 adenocarcinomas, 3 large-cell carcinomas, 14 small-cell carcinomas). In 18 non-small-cell lung cancer lines, gene alterations were found in 4 for K-ras (22%), none for H-ras (0%), 4 for p53 (22%) and none for the RB (0%) gene. In 14 small-cell lung cancer (SCLC) lines, no gene alterations were found in K-ras (0%), or H-ras (0%), but 6 were found for p53 (43%) and 3 for the RB (21%) gene. Coincident abnormalities of K-ras and p53, or K-ras and RB genes were not found in any cell lines, and those of the p53 and RB genes were found in only 2 SCLC lines. No association was observed between these three gene alterations and N-myc amplification. Although the above three genes may be involved to some extent in the pathogenesis of lung cancer, more factors are required for its development.     

Localization of MOC-1 cell surface antigen in small-cell lung carcinoma cell lines: an immunohistochemical and immunoelectron microscopic study

Expression of cell surface antigens of the neural cell adhesion molecule (N-CAM) class was recently shown to be shared by both fetal and neoplastic neuroendocrine cells, including those of the lung. We investigated the expression and localization of MOC-1 antigen on small-cell (neuroendocrine) lung carcinoma cell lines with immunohistochemical methods at the light (LM) and electron microscopy (EM) level and by Western blot. At LM level, using monoclonal antibody (MAb) MOC-1 with the ABC method and immunofluorescence, positive staining was observed on surfaces of cells from all tumor lines examined. Strongest immunostaining was found on cell surfaces of pulmonary small-cell carcinoma-derived cell line NCI-H69 with the majority of cells showing positive staining. An adherent variant of NCI-H69 cell line, H69V, exhibited positive staining in about 60% of cells, whereas only occasional cells of NCI-H727 cell line derived from pulmonary carcinoid tumor were positive for MOC-1 antigen. Western blot analysis confirmed these findings, showing a strong MOC-1-specific band in cell extracts of NCI-H69, with weaker band densities for H69V and NCI-H727. Immunoelectron microscopy (IEM) revealed that MOC-1 was not uniformly distributed on the outer surface of plasma membrane; immunogold particles appeared concentrated in areas of thick cell surface "fuzz" coating, surface microvilli, and in areas of cell-cell contact. In some cells, areas of plasma membrane invaginations and a few intracytoplasmic vesicles were also labeled, suggesting endocytosis. Surface labeling for SEM confirmed the finding of more dense labeling over the microvilli, cell membrane folds, and in areas of cell-cell contact. The cell lines derived from pulmonary neuroendocrine cell tumors can provide a useful model to study the role and function of neural adhesion molecules in pulmonary neoplasia and during lung development.     

Ectopic ACTH secretion: a heterogeneous entity

OBJECTIVES: ACTH-secreting non-pituitary tumors are a rare cause of Cushing's disease. We report the clinical course, prognostic aspects and molecular analysis data in three patients for whom the diagnosis was confirmed but who had variable clinical features and laboratory results. CASE REPORTS: Patient n degree 1 had severe hypercorticism which rapidly progressed to death 13 months after diagnosis. In patient n degree 2, signs of hypercorticism severe, leading to death 5 years after discovery of the causal carcinoid tumor. Patient n degree 3 had moderate hypercorticism and has survived for more than 25 years. DISCUSSION: These 3 ectopic tumors are representative examples of a wide range of possible ACTH-secreting ectopic tumors. In highly malignant poorly-differentiated tumors such as small-cell anaplastic carcinomas, ACTH production is aberrant and poorly controlled, and thus not particularly effective. At the other extreme, typical benign bronchial carcinomas have a high degree of neuroendocrine differentiation and secrete ACTH in a well-controlled manner difficult to distinguish from corticotropic adenomas, further exaggerating the diagnostic pitfalls.     

Thyroidal oxyphilic tumors

Treatment of thyroidal oxyphilic (Hurthle cell) tumors is controversial due to difficulties in grading tumor malignancy. We classify these tumors into 3 histological subtypes: adenomas, atypical adenomas, and carcinomas. The purpose of this study was to find out whether this classification is a useful criterion for determination of the extent of surgery. Our retrospective study included 5 cases of adenoma, 2 of atypical adenoma and 13 of carcinoma. All histological specimens were revised and were stained immunohistochemically for thyroglobulin. All specimens were positive for thyroglobulin; staining for factor VIII was performed in cases in which the tumor had penetrated into blood vessels. Hemithyroidectomy was used for typical adenomas, while atypical adenomas were treated as carcinomas and total thyroidectomy was performed. 5 patients were treated with radioactive iodine. Taking into account the clinical results, we conclude that histological subtype is a useful guide for proper surgical management. Hemithyroidectomy is proper therapy for adenomas. The management of atypical adenomas was not determined as all were treated as carcinomas.     

Bronchial carcinoid tumors

Bronchial carcinoid tumors, termed (incorrectly) "bronchial adenomas" in the past, are uncommon pulmonary neoplasms. These tumors are currently classified as neuroendocrine in origin because of their potential to form and sometimes secrete a variety of chemical substances. Overall, approximately 75% of bronchial carcinoid tumors arise in the lobar bronchi, 10% occur in the main-stem bronchi, and 15% originate in the periphery of the lung. Well-differentiated carcinoid tumors constitute almost 90% of all bronchial carcinoids. Atypical carcinoid tumors have a higher malignant potential than do typical bronchial carcinoids. The carcinoid syndrome is rarely, if ever, associated with carcinoids limited to the tracheobronchial tree. Occasionally, Cushing's syndrome due to ectopic hormone production is caused by bronchial carcinoid tumors. More than 75% of bronchial carcinoids are detected on conventional posteroanterior chest roentgenograms. Computed tomography may help disclose small neoplasms that are occult on conventional roentgenography, particularly in the assessment of patients who have Cushing's syndrome due to ectopic hormone production. Pulmonary resection is the treatment of choice for bronchial carcinoids. The prognosis is related to the pathologic grade and stage of the tumor.