[Heart valves (anatomo-pathologic study of 1139 cases]. / Válvulas cardíacas (estudio anatomopatológico de 1139 casos).

We review the pathological specimens sent to the Pathology Department from January 1983 to June 1988 that belonged to 7567 patients. For this study we have selected specimens from 1139 patients (15.05% of the total), who were submitted to valvular replacement surgery. We analyzed 1037 "native" valves and 186 prosthesis. Rheumatic fever was confirmed in 68% of "native" valves. The remaining 32% includes a group in which this etiology was not confirmed by histology in spite of the clinical diagnosis. The leading cause of biological prosthesis replacement was dysfunction caused by calcification and fibrosis, and for mechanical prosthesis it was thrombosis. Included in this study are 747 patients who received 836 heterologous valves of bovine pericardium, fabricated at the "Instituto Nacional de Cardiología (INC)". The price of imported mechanical prosthesis is superior to the price of the prosthesis manufactured at INC. The difference varies between 1400% and 4000% depending on mechanical prosthesis type. The survival rate of the receiving patients of the INC implants was 82.2%, and the dysfunction rate of these prosthesis was 3.38% for the period studied, four and a half years.

[Primary non-Hodgkin's lymphoma of the lung]. / Linfoma no Hodgkin pulmonar primario.

A case of small and large cells non Hodgkin lymphoma with an unusual involvement of the lung is presented. The tumor was located in the inferior lower lobe of the right lung and coincided with hemorrhagic pleural effusion. The cytopathological study of the fluid was negative for neoplastic cells, so were the aspiration biopsy of the lung and the pleural biopsy. The transmission and scanning electron microscopic study of the pleural fluid demonstrated lymphoid atypical cells. The patient was treated by resection of the lower right lobe and pleurectomy. The difficulties in the differential diagnosis of this type on non Hodgkin lymphoma are discussed. The importance of scanning and transmission electron microscopy is stressed when the light cytologic studies are negative in processes suggestive of being neoplasms. After one year of the lobectomy and treatment with vincristine-epirubicin-cyclophosphamide and methyl-prednisolone, the patient is in good condition without evidence of neoplastic activity.

[Prevention of coronary atherosclerosis. (V). Prevalence of non-stenotic atheromatous rigidity in men accidentally killed in Mexico City]. / Prevención de la aterosclerosis coronaria. (V). Prevalencia de rigidez ateromatosa no estenótica en hombres muertos accidentalmente en la ciudad de México.

The presence of rigid coronary arterial segments was detected during a survey for coronary atherosclerosis in men who died of violent causes. These lesions which traditionally are considered of non-clinical significance, in the absence of stenosis are probably responsible of the clinical and electrocardiographical abnormalities as seen in patients with "normal" coronary arteries using coronary angiography, the best current procedure for the detection of isolated coronary atherosclerosis. We propose these lesions are to be considered as functional lesions and consequently that these lesions should be considered by both, the pathologist and the clinician. Our hypothesis is to be tested in the near future when new diagnostic advances with the possibility of detection of coronary pathology in vivo, appear. The prevalence of these abnormalities in different age-groups as well as the topography are presented. The concordance of these lesions with coronary stenosis is also presented.

Is atherosclerosis increasing in Mexico City?

This report compares quantitative measures of atherosclerosis in aortas and coronaries from autopsies of deceased men from Mexico City collected during 1960 to 1964 and 1986 to 1987. The comparison of lesions in two different time periods provides an opportunity for determining whether the extent of atherosclerosis has changed over time in Mexico City. Three pathologists independently evaluated the extent of fatty streaks (FS), fibrous plaques (FP), calcified plaques (CA), and complicated lesions (CO) in 165 aortas and 120 sets of coronary arteries collected during 1986 to 1987 for comparison with similar gradings of 128 aortas and coronary arteries from the International Atherosclerosis Project in 1960 to 1964. Neither FS nor more advanced lesions differed significantly in either the descending thoracic or abdominal aorta between the two collection periods. In contrast, there were more extensive FP and raised atherosclerotic lesions (RL = FP + CA + CO) in the coronary artery segments evaluated in the younger age groups in 1986 to 1987 versus 1960 to 1964. Additional analyses, based on 75 pairs of aortas and 32 pairs of coronary arteries from age-matched cases, all regraded by the team of pathologists after blind coding, showed more FS in both aortic segments and more extensive involvement with RL in the three main branches of the coronary arteries in the more recent study. An overview of our findings suggests that atherosclerosis, particularly in the coronary arteries, is increasing in Mexico City. This hypothesis merits careful testing in parallel with consideration of possible changes in the risk factors that could be responsible for changes in extent of lesions.

[Prevention of coronary atherosclerosis: (IV): Prevalence of aortic atherosclerosis in Mexico, D.F. Its relation to coronary atherosclerosis]. / Prevención de la aterosclerosis coronaria: (IV): Prevalencia de la aterosclerosis aórtica en México, D.F. su relación con la aterosclerosis coronaria.

The severity and prevalence of coronary and aortic atherosclerosis was studied in 174 subjects who died from violent causes in Mexico City. As in other geographic areas, fatty streaks were found early in life (12 years old). Fibrolipid plaques were present in the thoracic aorta at age 15 and at age 19 in the abdominal segment. Complicated lesions were detected in the aorta after age 25. Because of the obvious clinical significance we looked for severe aortic lesions in the abdominal bifurcation. The prevalence of severe lesions in the bifurcation was 0 between 15 to 24 years and raised to 23.3% in the 45-54 age group. A moderate correlation was found between the severity of coronary and aortic lesions. The discordance most often found was the presence of severe coronary lesions without severe aortic involvement.

[Prevention of coronary atherosclerosis. II: Topography and morphology of "protruding" lesions. Epidemiologic, diagnostic and therapeutic implications]. / Prevención de la aterosclerosis coronaria. II: Topografía y morfología de lesiones "protruyentes". Implicaciones epidemiológicas, diagnósticas y terapéuticas.

Topographic and morphologic aspects of coronary atherosclerotic "protruding" lesions were investigated in 119 accidental deaths in males living in Mexico City. Morphology and topography varied according to the arterial trunk studied and age. Left anterior descending and circumflex lesions were almost always confined to the initial 5 cms and if a lesion was present after the 3rd cm there was always a proximal lesion. Right coronary lesions occasionally were found distally even in the absence of proximal lesions. Third decade lesions were usually not calcified. Stenosis if present was rarely multivascular. Some fourth decade lesions were calcified; plurivascular stenosis was present in some cases. Fifth decade lesions show sequential stenotic lesions in the same vessel; calcium and plurivascular stenosis were often observed. However the features observed in the 3rd decade could be observed in the older subjects. Reference is made to lesions which are found in both the left main trunk and the left anterior descending. Epidemiological and clinical applications related with preventive programs are mentioned.

Intramitochondrial lamellar bodies in acute myeloblastic leukemia.

Intramitochondrial lamellar bodies were observed in three cases of acute myeloblastic leukemia. Two of the patients had M1 leukemia and the remaining patient M4 leukemia, by the FAB classification. In all three cases neoplastic cells contained dilated mitochondria that varied in size and shape and contained decreased numbers of cristae. Some mitochondria contained lamellar structures that resembled myelin figures and, occasionally, primary granules; these structures were more conspicuous in the central portion of the mitochondria. Regardless of the proliferating cell type (lymphoblasts, myeloblasts, or monoblasts), there are common ultrastructural changes that represent abnormal metabolic function, such as disorders of intramitochondrial protein synthesis. The exact meaning of these findings is not known; adequate interpretation will require further investigation of the biology of these neoplastic processes.

[Anatomopathologic and ultrastructural study of cardiac myxomas]. / Estudio anatomopatológico y ultraestructural de los mixomas cardíacos.

For clinicians, cardiac myxomas has been a diagnostic challenge. It may simulate a valvular disfunction. The present paper displays the morphologic aspects on 17 patients with the diagnosis of atrial myxoma. In 14 cases the tumor was located in the left atrium. In all the cases stellate shaped cells were seen within a myxoid matrix. The findings in this report support the idea that myxomas are tumors and not thrombi as it has been speculated in the literature. We also consider that the cell of origin of this neoplasm is a pluripotential cell which needs further studies.

[Prevalence of microscopic coronary atheroma in young adults from Mexico City]. / Prevalencia del ateroma coronario microscópico en adultos jóvenes de la Ciudad de México.

The prevalence of microscopic atheroma in the proximal left anterior descending coronary artery was studied in thirty young males aged 20 to 29 years, living in Mexico City, who died in urban accidents. All of them were either unemployed or labor workers with a socioeconomical status considered to be representative of the majority of young males living in Mexico City. It was found that coronary atheroma was present in 11 of them (33%) with variable degrees of luminal obstruction. In two of them the luminal obstruction was greater than 75%. The prevalence found in this group was significantly different to that found in younger and older males who also died in accidents. Since the prevalence of coronary atheroma was not related to ventricular hypertrophy, valvular or congenital heart disease our findings indicate that in Mexico City as in other geographical regions, coronary atherosclerosis is not an unusual finding in males in the third decade of life, with a low socioeconomical status.