Morphological characteristics, classifications and difficulties in the use of diagnostic criteria for serrated lesions of the large intestine

Abstract: Introduction Colorectal carcinoma (CRC) is the most common gastrointestinal neoplasm in the world, accounting for 15% of cancer-related deaths. This condition is related to different molecular pathways, among them the recently described serrated pathway, whose characteristic entities, serrated lesions, have undergone important changes in their names and diagnostic criteria in the past thirty years. The multiplicity of denominations and criteria over the last years may be responsible for the low interobserver concordance (IOC) described in the literature. Objectives: The present study aims to describe the evolution in classification of serrated lesions, based on the last three publications of theWorld Health Organization (WHO) and the reproducibility of these criteria by pathologists, based on the evaluation of the IOC. Methods: A search was conducted in the PubMed, ResearchGate and Portal Capes databases, with the following terms: sessile serrated lesion; serrated lesions; serrated adenoma; interobserver concordance; andreproducibility.Articlespublished since 1990were researched. Results and Discussion: The classification of serrated lesions in the past thirty years showed different denominations and diagnostic criteria. The reproducibility and IOC of these criteria in the literature, based on the kappa coefficient, varied in most studies, from very poor to moderate. Conclusions: Interobserver concordance and the reproducibility of microscopic criteria may represent a limitation for the diagnosis andappropriatemanagementof these lesions. It is necessary to investigate diagnostic tools to improve the performance of the pathologist's evaluation, for better concordance, and, consequently, adequate diagnosis and treatment. (AU)

Recurrent non-functioning pituitary adenomas: a review on the new pathological classification, management guidelines and treatment options.

At least 50% of surgically resected non-functioning pituitary adenomas (NFPA) recur. Either early or late adjuvant radiotherapy is highly efficacious in controlling recurrent NFPA but associates potentially burdensome complications like hypopituitarism, vascular complications or secondary neoplasm. Reoperation is indicated in bulky tumor rests compressing the optic pathway. To date, no standardized medical therapy is available for recurrent NFPA although cabergoline and temozolomide show promising results. Guidelines on the management of recurrent NFPAs are now available. The new 2017 WHO pituitary tumor classification, based on immunohistochemistry and transcription factor assessment, identifies a group of aggressive NFPA variants that may benefit from earlier adjuvant therapy. Nevertheless, NFPA patients exhibit a reduced overall life expectancy largely due to hypopituitarism and treatment-related morbidity. The management of recurrent NFPA benefits from a multidisciplinary teamwork of surgeons, endocrinologists, radiation oncologists, ophthalmologists, pathologists and neuro-radiologists in order to provide individualized therapy and anticipate deterioration.

Adenoma de células basales parotídeo: reporte de un caso, manejo terapéutico y revisión de la literatura / Basal cell adehoma of the parotid gland: report of a case, therapeutic management and review of the literature

El adenoma de células basales de las glándulas salivares es un tipo deadenoma de aparición infrecuente. La localización más habitual es la superficie de la glándula parótida. Suele debutar clínicamente como una masa fi rme y desplazable de crecimiento lento, asintomática, que puede distinguirse a la palpación en el examen clínico. Afecta más a las mujeres, entre 35 y 80 años. Histológicamente: se observan cordonesy trabéculas de células epiteliales delimitadas por células basaloides y formaciones microquísticas, sin componente mixocondroide del tumormixto, como el presente caso. Se puede dividir en cuatro subtipos atendiendoa su morfología: sólido, tubular, trabecular y membranoso. El tratamiento preferido es la escisión quirúrgica conservadora que incluyeun reborde o margen de tejido normal no afectado. Describimos un caso clínico de adenoma de células basales de la glándula parótida; el hallazgo de esta patología en particular, es muy rara y poco documentada, además realizamos una revisión de la literatura y discutimos el manejo terapéutico y conservador de esta rara enfermedad.

Basal cell adenoma of the salivary glands is a rarely seen type of adenoma.Its most frequent location is the surface of the parotid gland. Itusually appears as a fi rm, mobile, slow-growing asymptomatic mass,which can be detected by palpation during clinical examination. Itis more prevalent in women between the age of 35 and 80 years.Histologically, cords and trabeculae of epithelial cells bounded bybasaloid cells and microcystic formations are visible, without themyxochondroid component of mixed tumors, as in the present case.The basal cell adenoma can be divided into four subtypes based onmorphology: solid, tubular, trabecular and membranous. The treatmentof choice is conservative surgical excision that includes a rimor margin of normal uninvolved tissue. We describe a clinical case ofbasal cell adenoma of the parotid gland, a particular disease that isvery rarely found and seldom documented. We also perform a reviewof the literature and discuss the conservative therapeutic managementof this unusual disease.

[Pituitary tumors: 10 years of experience]. / Adenomas hipofisarios: análisis de la casuística de 10 años.

INTRODUCTION: Pituitary tumors comprise a quarter of the intracranial neoplasms and the adenomas represent the highest percentage of them. They are benign, but they can be invasive and they have an impact in morbidity and mortality. OBJECTIVE: To analyze the clinical features of pituitary adenomas tumors, and create a computerized registry to improve strategies for diagnosis and monitoring of these patients. METHODS: A retrospective, descriptive analysis of 102 medical records of a total of 191 patients who attended the endocrinology service from 2003 to 2014 .The variables were analyzed by the corresponding descriptive statistics. The SPSS 11.5 was used. RESULTS: 63% were women, and (74.4%) had age from 25-60 years. 54% were nonfunctioning adenomas, 28% to prolactinomas, 11.8% and 6.2% somatotropinomas corticotropinomas. In all types the female group was predominant, except nonfunctioning. Of the nonfunctioning adenomas 79% were macroadenomas, prolactinomas 52% were microadenomas and surgery was performed in 37% of them. The somatotropinomas, 80% were macroadenomas, 80% of patients and 40% radiotherapy was operated. In corticotropinomas, both micro and macroadenomas were submitted by the same percentage (50%) and all of them underwent surgery. CONCLUSION: The findings are consistent with the literature in terms of frequency and age of onset of adenomas. We suggest the development of a registry to optimize the monitoring and treatment of patients, research and scientific publication.

Introducción: Los tumores hipofisarios comprenden la cuarta parte de las neoplasias intracraneales y los adenomas son el mayor porcentaje de ellos. Son de naturaleza benigna, pero pueden ser invasivos y producir impacto en la morbi-mortalidad. Objetivo: analizar las características clínicas de los pacientes con diagnóstico de adenomas hipofisarios y crear un registro computarizado para mejorar las estrategias de diagnóstico y seguimiento de estos pacientes. Metodología: Se realizó un análisis retrospectivo, descriptivo, de 102 historias clínicas sobre un total de 191 pacientes que concurrieron al servicio de endocrinología desde el año 2003 al 2014 . Las variables fueron analizadas mediante las correspondientes estadísticas descriptivas. Se utilizó el programa SPSS 11.5. Resultados: El 63% fueron mujeres, y el mayor porcentaje etario entre 25-60 años (74.4%). El 54% correspondió a adenomas no funcionantes, el 28% a prolactinomas, el 11.8% somatotropinomas y el 6.2% corticotropinomas. En todos los tipos el grupo femenino fue mayoritario, excepto en los no funcionantes. De los adenomas no funcionantes el 79% fueron macroadenomas, los prolactinomas el 52% fueron microadenomas y se realizó cirugía en el 37% de ellos. Los somatotropinomas, en el 80% fueron macroadenomas, se operó el 80% de los pacientes y radioterapia al 40%. En los corticotropinomas, tanto micro como macroadenomas se presentaron en igual porcentaje (50%) y todos ellos recibieron tratamiento quirúrgico. Conclusión: Los hallazgos coinciden con la literatura en cuanto a frecuencia y edad de presentación de los adenomas. Consideramos valioso la elaboración de un registro que nos permita optimizar el seguimiento y tratamiento de los pacientes, la investigación y divulgación científica.

Aromatase P450 expression in human pituitary adenomas.

Estrogen has been shown to play an important role in pituitary tumor pathogenesis. In humans, this biosynthesis is mediated by aromatase, an enzyme that converts androgens to estrogens. Just a few studies about aromatase expression in human pituitary gland, both in normal and pathological ones, are found in the literature. This study aimed to assess aromatase enzyme expression in human pituitary adenomas and associate it with gender, tumor size and tumor subtype. We conducted a cross-sectional study, reviewed clinical data and surgical specimens of consecutive 65 patients (35 women and 30 men) with anatomopathologic diagnosis of pituitary adenoma who underwent adenomectomy at a neurosurgical referral center in southern Brazil. Immunohistochemistry was performed to assess aromatase expression and define tumor subtype, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) to estimate aromatase gene expression. Mean patient age was 45.6 (±13.3) years (range, 18 to 73 years), 86.2% of our samples were macroadenomas while 13.8% were classified as microadenomas. Based on clinical and immunohistochemical data, 23 (35.4%) patients had non-functioning adenomas, 19 (29.2%) had somatotroph adenomas (acromegaly), 12 (18.5%) had lactotroph adenomas (hyperprolactinemic syndrome), and 11 (16.9%) had corticotroph adenomas (Cushing's disease). Immunohistochemical analysis was performed in 59 cases, and 58 (98.3%) showed no aromatase expression. Quantification by qRT-PCR was performed in 43 samples, and 36 (83.7%) revealed no gene expression. Among tumor specimens examined by both techniques (37 cases), 30 showed no gene or protein expression (concordance index, 0.81). It is possible to mention that aromatase expression was lost in most pituitary adenomas, regardless of gender, tumor subtype, or tumor size.

Adenomas invasores, presentación de caso, revisión de la literatura y propuesta de clasificación según su extensión / Invasive adenomas, case report, literature review and proposal for classification according to their extensión

Los adenomas hipofisiarios invasores constituyen una patología de baja frecuencia dentro de los tumores del sistema nervioso central, su nombre hace referencia a aquellas lesiones que se extienden hacia estructuras adyacentes a la región selar y que en algunas ocasiones pueden alcanzar tamaños gigantes. Representan un importante reto quirúrgico considerando la posibilidad de daño de las estructuras comprometidas o rodeadas por el tumor. Son lesiones que se manifiestan de forma tardía y generalmente más por su efecto compresivo que por un compromiso hormonal secundario. Existen múltiples clasificaciones partiendo de la extensión del tumor, además de las que hacen referencia a las características histológicas. En este artículo se exponen los sistemas de clasificación así como algunos de los abordajes reportados en la literatura. Se muestra el caso de una de nuestras pacientes a quien se le diagnosticó tardíamente un adenoma invasor de gran tamaño, después de varios años de cursar con importantes alteraciones del comportamiento y quien posteriormente fue llevada a cirugía para resección del tumor por vía transcranial. Se expone la complejidad anatómica de la región selar y se propone un nuevo sistema de clasificación que contempla el compromiso diferencial de espacios y estructuras neurales y vasculares adyacentes a la región selar con el fin de guiar a los cirujanos sobre los procedimientos quirúrgicos más adecuados y disponibles en el momento.

Invasive pituitary adenomas constitute a low-frequency disease within the central nervous system tumors, the name refers to those lesions involving adjacent structures to the sellar region and who can reach giant sizes. The invasive adenomas represent a major challenge considering surgical morbidity due to the commitment of structures that may be involved given the extent of these lesions. These tumors usually are belatedly manifested and their manifestations are most often secondary to the compressive effect than hormonal involvement. There are multiple classifications based on the extent of the tumor, besides those that referring to the histologic features. This article shows a case of a patient who was diagnosed lately, with a big invasive adenoma who had had major behavioral disturbances in previous years and was subsequently taken to surgery for resection of the tumor. We present the anatomical complexity of the sellar region and we propose a new classification system to guide surgeons on the surgical procedure most suitable and available at the time.

Endoscopic endonasal transsphenoidal surgery: surgical results of 228 pituitary adenomas treated in a pituitary center.

Pituitary tumors are challenging tumors in the sellar region. Surgical approaches to the pituitary have undergone numerous refinements over the last 100 years. The introduction of the endoscope have revolutionized pituitary surgery. The aim of this study is to report the results of a consecutive series of patients undergoing pituitary surgery using a pure endoscopic endonasal approach and to evaluate the efficacy and safety of this procedure. We reviewed the data of 228 consecutive patients who underwent endonasal transsphenoidal adenoma removal over an 10-year period. Pre- and post-operative hormonal status (at least 3 months after surgery) were analyzed and compared with clinical parameters presented by the patients. Tumor removal rate, endocrinological outcomes, and complications were retrospectively assessed in 228 patients with pituitary adenomas who underwent 251 procedures between December 1998 and December 2007. There were 93 nonfunctioning adenomas, 58 growth hormone-secreting, 41 prolactin-secreting, 28 adrenocorticotropin hormone secreting, 7 FSH-LH secreting and 1 thyroid-stimulating hormone-secreting adenomas. Gross total removal was achieved in 79.3% of the cases after a median follow-up of 61.5 months. The remission results for patients with nonfunctioning adenomas was 83% and for functioning adenomas were 76.3% (70.6% for GH hormone-secreting, 85.3% for prolactin hormone-secreting, 71.4% for ACTH hormone-secreting, 85.7% for FSH-LH hormone-secreting and 100% for TSH hormone-secreting), with no recurrence at the time of the last follow-up. Post-operative complications were present in 35 (13.9%) cases. The most frequent complications were temporary and permanent diabetes insipidus (six and two cases, respectively), syndrome of inappropriate antidiuretic hormone secretion (two cases) and CSF leaks (eight cases). There was no death related to the procedure in this series. The endoscopic endonasal approach for resection of pituitary adenomas, provides acceptable results representing a safe alternative procedure to the microscopic approach. This less invasive method, associated with a small number of complications, provides excellent tumor removal rates and represents an important tool for the achievement of good results in the pituitary surgery, mainly for the complete removal of large adenomas.

Class distinction between follicular adenomas and follicular carcinomas of the thyroid gland on the basis of their signature expression.

BACKGROUND: Nodules of the thyroid gland are observed frequently in patients who undergo ultrasound studies. The majority of these nodules are benign, corresponding to goiters or adenomas, and only a small fraction corresponds to carcinomas. Among thyroid tumors, the diagnosis of follicular adenocarcinomas by preoperative fine-needle aspiration biopsy is a major challenge, because it requires inspection of the entire capsule to differentiate it from adenoma. Consequently, large numbers of patients undergo unnecessary thyroidectomy. METHODS: Using data from gene expression analysis, the authors applied Fisher linear discriminant analysis and searched for expression signatures of individual samples of adenomas and follicular carcinomas that could be used as molecular classifiers for the precise classification of malignant and nonmalignant lesions. RESULTS: Fourteen trios of genes were described that fulfilled the criteria for the correct classification of 100% of samples. The robustness of these trios was verified by using leave-1-out cross-validation and bootstrap analyses. The results demonstrated that, by combining trios, better classifiers could be generated that correctly classified >92% of samples. CONCLUSIONS: The strategy of classifiers based on individual signatures was a useful strategy for distinguishing between samples with very similar expression profiles.

Tumorigênese hipofisária / Pituitary tumorigenesis

Os tumores hipofisários, adenomas na sua quase totalidade, representam de 10 por cento a 15 por cento das neoplasias intracranianas (1) e são encontrados em até 27 por cento de autópsias não selecionadas, como achado incidental (2). Morfologicamente são classificados em microadenomas (< 1cm de diâmetro) e macroadenomas, que podem ser circunscritos, invasivos e/ou expansivos. Do ponto de vista funcional, são divididos em adenomas secretores (de PRL, GH, ACTH, TSH, LH e FSH, podendo co-secretar dois ou mais hormônios) e clinicamente não secretores ou "não funcionantes". O diagnóstico é feito pelo fenótipo da hipersecreção (acromegalia, Cushing etc.) e, nos macroadenomas com efeito de massa, por hipopituitarismo e/ou distúrbios neurológicos, onde predominam as queixas visuais e cefaléia. Quanto aos mecanismos de tumorigênese hipofisária, a disputa entre causa primária hipotalâmica versus hipofisária ganhou força a favor da segunda graças às evidências da monoclonalidade dos tumores, juntamente com outros argumentos como a ausência de tecido hiperplásico circundando o adenoma cirurgicamente removido e a relativa independência do controle hipotalâmico. No entanto, admite-se que um papel permissivo do hipotálamo é importante para a progressão tumoral. Muitos mecanismos moleculares envolvidos na tumorigenese hipofisária já foram desvendados, incluindo oncogenes, genes supressores tumorais e fatores de crescimento, e serão descritos neste artigo de revisão.

[Pituitary tumorigenesis]. / Tumorigênese hipofisária.

Pituitary adenomas, almost invariably adenomas, account for 10% to 15% of all intracranial neoplasms and are incidentally detected in up to 27% of non selected autopsies. They are morphologically classified as microadenomas (diameter < 1 cm) or macroadenomas, which can be enclosed, invasive and/or expansive. Functionally, they are classified as secreting adenomas (PRL, GH, ACTH, TSH, LH, and FSH, and those co-secreting two or more hormones), and clinically non secreting or "non functioning" tumors. Diagnosis is based on the hypersecretion phenotype (acromegaly, Cushing, etc), and on mass effect of macroadenomas leading to neurological disturbances, mainly visual complaints and headache. Pituitary tumorigenesis mechanisms include those of primary hypothalamic versus pituitary origin, the latter is supported by evidence of pituitary adenoma monoclonality, as well as the absence of hyperplastic tissue surrounding the surgically removed tumor, and the relative independence of tumor hypothalamic control. Nevertheless, a permissive role of the hypothalamus on tumor progression is also postulated. Several molecular mechanisms involved in pituitary tumorigenesis have been unraveled including oncogenes, tumor suppressor genes and growth factors involved in neoplastic development, and will be described in this review.

Immunohistochemical detection of estrogen receptor alpha in pituitary adenomas and its correlation with cellular replication.

With the aim of evaluating the relationship between pituitary tumorigenesis and the presence of estrogen receptor-alpha (ERalpha) by immunohistochemistry (IH) and their relevance to patients' clinical presentation, hormonal phenotypes of adenomas, preoperative neuroimaging findings, and the index of cellular replication MIB-1, a study was conducted with material from 91 women and 67 men with pituitary adenomas. The patients had acromegaly (29.7%), Cushing's disease (14.6%), hyperprolactinemic syndrome (20.9%), and clinically nonfunctioning tumors (34.8%). Of the patients, 14.6% had microadenomas, 52.5% had macroadenomas with or without suprasellar growth, 28.5% had invasive macroadenomas and in 4.4% the adenoma was not visualized. IH showed that 43 were positive for growth hormone (GH), 16 for corticotropin (ACTH), 18 for prolactin (PRL), 18 for PRL+GH, 6 for luteinizing hormone (LH) and follicle-stimulating hormone (FSH), 15 had a plurihormonal reaction, and 42 had nonfunctioning adenomas. The presence of ERalpha was positive in 9/158 adenomas with a median value for the percentage of labeled cells of 42.89%, and in 6/16 controls (autopsy samples) with a median value for the percentage of labeled cells of 0.024%. ERalpha was significantly more prevalent in controls than in patients with adenomas (37.5 versus 5.7%; p = 0.001); however, the mean ERalpha concentration in adenomas was significantly greater than in controls (42.89 versus 0.024%; p < 0.001). No significant difference in the concentration of ERalpha was found across the clinical presentations, hormonal phenotypes or findings of preoperative CT. Among the ERalpha-positive adenomas, ERalpha values were significantly greater in invasive macroadenomas (80%) than in microadenomas (3.33%). MIB-1 values did not differ significantly between ERalpha-positive and -negative adenomas, nor did the correlation between ERalpha values and the MIB-1 index attain significance in the total sample, even when only ERalpha-positive adenomas and positive MIB-1 indexes were considered. It was concluded that, when present in pituitary tumors, ERalpha exhibits a high concentration, and is more common in nonfunctioning and invasive adenomas, but absent in ACTH-secreting ones.

[Gastric epithelial polyps (first part)]. / Pólipos epiteliales gástricos (primera parte).

The following is a statistical report regarding gastric polyps:Frequency determined through endoscopic examinations was 3.6%. The terms hyperplastic polyps and adenomas were used for the classification of epithelial polyps, considering the suprafoveal hyperplasias within the hyperplastic polyps, provided they were elevated lesions. Out of 2,283 polyps, 1,959 were hyperplastic (86%) and 324 were adenomas (14%). When analyzing 780 polyps, 86 (11%) were found to have the Nakamura III category. With regard to topography, in an examination of 2253 polyps, hyperplastic polyps were located as follows: 325 (17%) in the antrum, 1402 (73%) in the body and 202 (10%) in the fundus. Adenomas had a different distribution: 212 (65%) in the antrum, 100 (31%) in the body and 12 (4%) in the fundus. Out of 371 hyperplastic polyps examined, 49% were pediculate and 51% were sessile; on the contrary, 86 % of adenomas were sessile. The average age was 66.2 years in adenoma carriers, 58.5 in those having hyperplastic polyps, and 57.4 for suprafoveal hyperplasias. In 287 adenomas, 94.1% of carriers were over 40 years old. Out of 92 adenomas examined, 21.7% evidenced adenoma metaplasia and 72.8% evidenced metaplasia in adjacent areas. Only 5.5% had no metaplasia. In 105 hyperplastic polyps studied, intestinal metaplasia was found: 16.7% in the polyp and 60% in adjacent areas. No metaplasia was found in the remaining 23.3%. Average size of the adenomas was 14 mm and of hyperplastic polyps, 11 mm. A total of 195 adenomas were smaller than 10 mm. The percentage of malignization in 288 adenomas examined was closely related to their size: 214 (66%) smaller than 20 mm, had a malignization percentage of 7%; 74 (34%) larger than 20 mm, had 51% malignization, and 86.2% malignization was found in adenomas of over 40 mm.Global malignization percentage of adenomas was 18%. However, when adenomas with high grade dysplasia in the 4.1 category of the Viena classification (non-invasive high grade neoplasia) were considered, this percentage rose to 26%. Malignization of hyperplastic polyps was 0.8%. When gastric acidity was determined using the maximum stimulation method, out of 77 cases of patients with hyperplastic polyps, 55 (60%) had real achlorhydria, 10 (18%) hypochlorhydria, 11 (20%) normochlorhydria, and only 1 (4) hyperchlorhydria. D.A.B. was 1.97 mEql for hyperplastics and 1.60 mEql for adenomas. D.A.M. was 6.05 mEql for hyperplastics and 5.49 mEql for adenomas. Our experience as to normal cases showed 2.5 mEqh +/- 1.2 and 22 mEqh +/- 6, respectively, for D.A.B and D.A.M.

Pulmonary adenoma susceptibility 1 (Pas1) locus affects inflammatory response

Two outbred mouse lines, phenotypically selected for differential subcutaneous (s.c.) acute inflammatory response (AIR), were analysed for urethane-induced lung inflammatory response and susceptibility to lung tumorigenesis. AIRmin mice, which show a low response to s.c. acute inflammation, developed a persistent subacute lung inflammatory response and a 40-fold higher lung tumor multiplicity than did AIRmax mice, which are selected for high response to s.c. acute inflammation and showed a transient lung inflammatory response. A highly significant linkage disequilibrium pattern was observed in AIRmax and AIRmin mice at marker alleles located within a 452-kb pulmonary adenoma susceptibility 1 (Pas1) locus region, thus defining the location of gene candidacy for inflammatory response and for the biological effects of Pas1 in this region. AIRmin and AIRmax mice segregated by descent the Pas1s and Pas1r alleles, respectively, providing evidence for the involvement of the Pas1 locus in the inflammatory response. The 452-kb region contains Kras2 and four additional genes, including the lymphoid-restricted membrane protein (Lrmp) gene, whose Pro¨ Leu nonconservative variation was linked with inflammatory response and Pas1 allelotype. These results provide a model to explore the mechanism underlying inherited predisposition to lung cancer in the context of a link to inflammation.

Pólipos rectocolónicos: diagnóstico, tratamiento, revisión histológica y deguimiento / Rectocolonic polyps: diagnosis, treatment, histologic review and follow-up

Se efectúa un estudio restrospectivo sobre 499 pólipos rectocolónicos extirpados entre 1976 y 1989. Se tuvo en cuenta edad, sexo, localización topográfica, tamaño y forma e histología de pólipos extirpados. Se reexaminaron histológicamente 303 especímenes, ya que se descartaron 147 pólipos hiperplásicos y 49 por tratarse de material no aprovechable. La revisión histológica mostró importantes diferencias con el exámen primitivo. En los adenomas tubulares disminuyó la displasia moderada de 9,7 a 4,5%. No se halló displasia severa en este grupo. En los tubulovellosos se redujo la displasia severa de 6,3 a 3,1%. En 3 casos se halló seudoinvasión carcinomatosa en este grupo y también se encontró un carcinoma focal contra 3 hallazgos de invasión neoplásica en el estudio anterior. En los adenomas vellosos aumentaron las displasias leves y disminuyeron las severas. De los 15 pólipos informados como vellosos con adenocarcinoma se ocluyeron seis, 3 por seudoinvasión y 3 como afectados por displasia moderada. Se destacan los hallazgos de la revisión que mostró las mayores diferencias en las lesiones de alto grado de riesgo y la tendencia a una disminución en ese grado

Pólipos rectocolónicos: diagnóstico, tratamiento, revisión histológica y deguimiento / Rectocolonic polyps: diagnosis, treatment, histologic review and follow-up

Se efectúa un estudio restrospectivo sobre 499 pólipos rectocolónicos extirpados entre 1976 y 1989. Se tuvo en cuenta edad, sexo, localización topográfica, tamaño y forma e histología de pólipos extirpados. Se reexaminaron histológicamente 303 especímenes, ya que se descartaron 147 pólipos hiperplásicos y 49 por tratarse de material no aprovechable. La revisión histológica mostró importantes diferencias con el exámen primitivo. En los adenomas tubulares disminuyó la displasia moderada de 9,7 a 4,5%. No se halló displasia severa en este grupo. En los tubulovellosos se redujo la displasia severa de 6,3 a 3,1%. En 3 casos se halló seudoinvasión carcinomatosa en este grupo y también se encontró un carcinoma focal contra 3 hallazgos de invasión neoplásica en el estudio anterior. En los adenomas vellosos aumentaron las displasias leves y disminuyeron las severas. De los 15 pólipos informados como vellosos con adenocarcinoma se ocluyeron seis, 3 por seudoinvasión y 3 como afectados por displasia moderada. Se destacan los hallazgos de la revisión que mostró las mayores diferencias en las lesiones de alto grado de riesgo y la tendencia a una disminución en ese grado

Morphometric study of normal and adenomatous pituitary somatotrophs in humans.

Somatotrophs from ten pituitary adenomas were evaluated morphometrically by light and electron microscopy using the following parameters: a) nuclear, cytoplasmic and cell volumes; b) volume density, total volume, surface density, total surface and surface/volume ratio of secretory granules, mitochondria, rough endoplasmic reticulum and Golgi apparatus, and c) the number of secretory granules and mitochondria per micron3 of cytoplasm and per cell. The results were compared (p less than 0.05 and p less than 0.10) with those obtained from somatotrophs identified in five normal pituitaries. The data obtained indicate that: a) in the adenomas, the number of secretory granules per cell cannot be accurately evaluated from their apparent number in sectioned cell profiles; b) there are two basic sub-types of adenomatous somatotrophs defined according to the mean secretory granule diameter; cells in which granule diameter is inferior to 180 nm exhibit distinct morphological features such as nuclear pleomorphism, the presence of gross bundles of intermediate sized filaments or fibrous bodies in the cytoplasm and a variable number of secretory granules. Adenomas constituted mainly by these cells were found in younger patients, suggesting the more aggressive nature of these tumours, thus warranting close clinical follow-up of such patients; and c) in both types of adenomatous cells, the organelles directly involved in the secretory process, i.e., the rough endoplasmic reticulum and Golgi apparatus, are larger than in the control cells; however, the ratio between the surfaces of these two compartments does not differ among the three groups studied.