Advances and controversies in the classification and grading of pituitary tumors.

BACKGROUND: Pituitary tumors are common lesions, and they represent the second most frequent primary brain tumor. Their classification has undergone several changes over time. The World Health Organization conducts periodic expert review/consensus meetings and publishes the results as recommendations for changes in classification, based on advances in molecular and genetic advances. This paper summarizes the results of the 2017 WHO Classification, which recommends several important changes. PURPOSE: This paper provides a review of the major changes and issues leading to an understanding of the basis for a new pituitary tumor classification. They include the rejection and modification of prior conceptual and pathological characteristics of these neoplasms. There is also considerable concern related to invasive and recurrent pituitary tumors which follow a less benign course than the typical pituitary adenoma. METHODS: A review of the outcome data for the previously designated "atypical" pituitary tumor category revealed that the former criteria were not adequate to support their ability to predict with accuracy the clinical course of a given tumor. A similar review was accomplished regarding the role of the p53 tumor suppressor mutation. Again, there was no reliable contribution of p53 status to tumor aggressiveness. Other changes have occurred regarding the cytogenetic lineage of the various subtypes of pituitary adenoma. The transcription factors Pit-1, SF-1, and TPit play a major role in determining tumor subtypes and have become part of the classification criteria. RESULTS: These advances now help provide the background for more reliable and consistent classification of pituitary adenomas. Further definition of aggressive characteristics such as cavernous sinus and dural invasion remain to be considered in the quest to make more accurate prognostic projections based on histopathological analysis. CONCLUSIONS: The 2017 WHO Classification of Pituitary Tumors provides a more solid basis for accurate and reliable prognostic assessment of these lesions. Further progress undoubtedly will be made as the recommendations of this update are incorporated in to routine use.

Associação do methimazole e do ondansetron à quimioterapia com cisplatina em cães submetidos a quatro diferentes protocolos de fluidoterapia / Association of methimazole and ondansetron to cisplatin chemotherapy in dogs submitted to four different fluid therapy protocols

Utilizaram-se 12 cães, machos, distribuídos em quatro grupos (G) experimentais, selecionados de acordo com o tempo de fluidoterapia com solução fisiológica 0,9 por cento: G1 (sem fluidoterapia), G2 (uma hora de fluidoterapia antes da cisplatina), G3 (uma hora de fluidoterapia antes da cisplatina e uma hora após) e G4 (duas horas de fluidoterapia antes da cisplatina e uma após). Todos os animais receberam a cisplatina (70mg/m²), pela via intravenosa, sendo os ciclos de quimioterapia realizados em intervalos de três semanas, num total de três ciclos. O ondansetron (0,4mg/kg) foi administrado pela via intravenosa, a cada oito horas, no dia da quimioterapia e, a seguir, a cada 12 horas, por dois dias. O methimazole (40mg/kg) foi pela via oral, 30 minutos antes da cisplatina e quatro horas após. Avaliaram-se os parâmetros hematológicos, bioquímicos, urinários e dosagem de tiroxina e triiodotironina a cada sete dias até o término do experimento. Esse protocolo foi eficaz e seguro em cães que permaneceram sob fluidoterapia durante duas a três horas. Os animais que não receberam fluidoterapia e os que ficaram somente uma hora sob infusão intravenosa de solução fisiológica apresentaram alterações que resultaram em não-recomendação do protocolo.

Twelve male dogs were divided in four experimental groups (G), which were selected according to the time of 0.9 percent saline fluid therapy: G1 (without saline therapy), G2 (an hour of saline therapy before receiving cisplatin), G3 (an hour of saline therapy before receiving cisplatin and one hour after) and G4 (two hours of saline therapy before receiving cisplatin and one hour after). All the animals received 70mg/m² cisplatin, via intravenous, and the chemotherapy cycles were accomplished in intervals of three weeks, in a total of three cycles. Ondansetron (0.4mg/kg) was administered via intravenous, every 8 hours, on the day of the chemotherapy and, from that, every 12 hours for two days. Methimazole (40mg/kg) was orally administered 30 minutes before the cisplatin injection and four hours after. The hematological, biochemical and urinary parameters and dosages of tiroxin and triiodotironine were evaluated every seven days until the end of the experiment. This protocol was effective and safe in the animals that stayed for a period of two or three hours receiving saline therapy, because they did not present clinical and laboratory alterations of the use of chemotherapy. The animals that did not receive saline therapy and those that received infusion of physiologic solution via IV only during one hour presented alterations that made unfeasible the use of this protocol.