[Macro-microscopic comparative study of gallbladder lesions in La Plata (Argentina)]. / Estudio comparativo macro-microscópico de las lesiones vesiculares en La Plata (Argentina).

The histogenesis of the gallbladder carcinoma is under controversy Some authors emphasize the polyp-cancer sequence, whereas others relate the adenocarcinoma with metaplastic and dysplastic changes. It is important to examine immediately the characteristics of the mucosa, in order for guidance to the surgeon at the operating room. With the purpose of correlating the macro-microscopic findings of gallbladder lesions, we studied 306 gallbladder specimens extended and fixed in formaline. We considered: Age, sex, lithiasis, dimensions of the specimens and macroscopic patterns of the mucosal surface. Longitudinal samples were taken for histological examination. Two hundred and thirty seven cases corresponded to female sex (77.4%) and 69 to male sex (22.5%) with an average age of 44 years. Among the microscopic findings, we found gastric metaplasia in 43% of the cases, intestinal metaplasia in 10.8%, low grade dysplasia in 11.8% and high grade dysplasia in 1.6%, and 2 cases of clinically unsuspected invasive carcinomas (0.6%). An association between chronic colecistitis, lithiasis and epithelial changes was confirmed, but the relation between each one of the macroscopic patterns proposed and the histological findings is statistically significant only in the cases of atrophy, probably owing to the overlapping of microscopic findings in the different macroscopic patterns.

[Early flat colorectal cancer]. / Cáncer recto colónico temprano plano.

We report three cases of flat early colorectal carcinoma which were detected during the examination of 51 surgical specimens of colorectal resection. Two of them were endoscopically diagnosed, but the smallest one was not seen in the luminal instrumental examination. From the bibliographic analysis and our own experience we deduce the importance of flat lesions in the development of early colorectal carcinoma, either originated from pre-existent adenoma or de novo. Flat variants of adenoma, and presumably flush or depressed ones, must be considered as important factors in the early sequence adenoma-cancer. An appropriate endoscopic equipment with employment of additional staining techniques (such as carmine indigo and methylene blue) and the correct investigation during inflation-deflation procedures facilitates the identification of small lesions, their eradication and prevention from advanced forms of colorectal carcinoma.

[Systematic study of gastrectomy specimens for cancer, in search of synchronous carcinomas]. / Estudio sistematico de piezas de gastrectomia por cáncer en búsqueda de carcinomas sincrónicos.

Multiple carcinomas were searched in 50 successive gastrectomies, 17 females (34%) 33 males (66%) from 40 to 83 years old. Macroscopic handling of the specimens included pinning on a board, fresh, half-fixed and completely fixed examination, not only by naked eye but also through a magnifying glass. The stomach were totally studied, according to Japanese method. A satisfactory slide was obtained from each block, stained with H.E. and examined by each of the authors. Synchronous tumors were found in 4 cases (8%), 3 males and one female. Compared to the main lesion, two cases showed a proximal tumor, one case showed a distal tumor, and the last one showed two tumors, one of them proximal and the other distal. Three tumors were macroscopically and two were microscopically detected. Two of them coexisted with advanced carcinoma and three with early carcinoma. Four of them were located in mucosa with intestinal metaplasia. Histologically, four cases belong to the same type of the original tumor, and one of them did not coincide. We conclude that stomachs resected for cancer must be thoroughly and methodically studied before and after fixation. We suggest that resection must include the whole mucosa with intestinal metaplasia, in order to avoid leaving a synchronous tumor in the gastric stump.

[Current significance of polypectomy of the upper gastrointestinal tract]. / Significación actual de la polipectomía del tracto gastrointestinal superior.

Author's experience about 70 endoscopic polipectomy of high gastrointestinal tract, realized on 53 patients during 1978-1983 period was evaluated. Esophaguel polyps incidence was 0.06% among 7.900 endoscopic studies; gastric polyps was 0.8% and duodenal was 0.03%. Diagnosis was radiologically suspected in 58%. Gastric antrum was the predominant localization (45.7%) and macroscopic Yamada types IV (32.8%) and III (30.0%) were found more frequently. Most of patients presented solitary polips (86.7%). 63.2% of pieces were under 10 mm in size and 35.2% between 10 - 20 mm. High frecuency of adenomas (23.5%) and a low one of hyperplasiogenic (7.3%) was the prominent finding; only one case of early gastric cancer was founded (1.5%). Neither adenoms or hyperplasiogenic polyps were founded on gastric fundus, and no direct relation between size and histopatologic type was observed. Only one hemorragic complication (1.4%) was present. Polips incidence on 800 consecutive auptopsy protocols in adults was 0.12%.

[Sporadic dysplastic nevus syndrome. ULtrastructural observations]. / Síndrome del nevus displásico esporádico. Observación ultraestructural.

A case of sporadic dysplastic nevus syndrome is presented, with light and electronic microscopy. The absence of macromelanosomes in the ultrastructural studies of the nevoid lesion supports the nosological identity of the disease (histological marker).

[Benign cutaneous fibrohistiocytoma. Morphological analysis of 176 cases]. / Fibrohistiocitoma benigno cutáneo. Análisis morfológico de 176 casos.

We report a review of the morphologic and topographic characteristics of 176 cases of cutaneous fibrous histiocytoma. We confirm its prevalence in females with greater incidence of location in the limbs. Among the morphologic varieties the most frequent is the fibro-collagenous. The most common differential diagnosis comprises dermatofibrosarcoma protuberans, atypical fibroxanthoma, malignant fibrous histiocytomas and idiopathic fibromatosis. Its histogenesis from mesenchymal immature elements and its tendency toward fibrohistiocytic differentiation is generally accepted.

[Basocellular epithelioma. Considerations on its histogenesis]. / Epitelioma basocelular. Consideraciones acerca de su histogénesis.

Twenty-nine cases of basal cell carcinoma were studied with immunoperoxidase techniques for the detection of carcinoembryonic antigen. Results presented in the text would indicate that a high percentage of basal cell carcinomas have sweat gland histogenetic origins and that this is independent of its morphologic features. The use of immunohistochemical techniques in the detection of biological markers demonstrates once again their value not only in identifying a disease but also in determining its histogenetic origins.

Occult papillary thyroid carcinoma at autopsy in La Plata, Argentina.

Although clinically evident thyroid carcinoma is not a frequent neoplasm (incidence 2.7 per 100,000 persons in La Plata, Argentina), occult carcinomas are present in a high proportion of the population, but there are marked differences along geographical lines. The purpose of the present study is to establish the prevalence of occult papillary thyroid carcinoma (OPC) in La Plata. Thyroid glands obtained from 100 consecutive adult necropsies were examined. The material was fixed in buffered formaldehyde at 4 degrees C, serially sectioned at 2 mm intervals, and routinely processed. Eleven thyroid glands contained OPC, corresponding in three cases to multiple lesions. Eight carcinomas were found in 59 men (13.6%) and three in 41 women (7.3%). The ages ranged from 26 to 78 years. The neoplasms varied in size from microscopic foci to 9 mm in diameter. The prevalence rate of OPC in the present study is lower than that found in Finland, Japan, and the US, and higher than for the rest of the series recorded.

Solid cell nests of the thyroid gland. Optic and immunohistochemical study at autopsies.

In order to establish the prevalence of solid cell nests (SCN) in adult thyroids, we studied 100 consecutive glands at necropsy. These were serially sectioned and stained with routine and immunoperoxidase techniques in order to detect calcitonin, carcinoembryonic antigen, thyroglobulin and keratin. SCN may be considered as normal thyroid gland components, and they share with C cells a common origin in the ultimobranchial body.

Early colorectal cancer--follow-up after endoscopic polypectomy.

Approximately 90% of correctly indicated endoscopic polypectomies for early colorectal cancer, whether invasive or not, are curative, provided strict criteria are adopted in the pathological evaluation of the resected specimen. Unrestricted time surveillance is mandatory since benign (more frequent) or malignant relapses appear in 30-40% of the patients.