Pancreatic intraductal papillary mucinous neoplasm evolving into adenocarcinoma. Continual follow-up necessary.

We report a 62-year-old female with chronic pancreatitis after three episodes of severe acute pancreatitis. In 2008, an uneven main pancreatic duct (MPD) of 16 mm was found during an abdominal ultrasound. The follow-up was not continued until 2020, when a dilation of 27 mm of the MPD was discovered at magnetic resonance imaging (MRI). In 2022, another radiological test was carried out showing a dilation of the MPD of 40 mm with an intraductal tumoral lesion of 30 mm at the head of the pancreas). An echo-endoscopy was carried out and a pancreatic-duodenal tumour with a mixed pattern was discovered. Atypic cells were observed at the fine needle punction. A total duodenopancreatectomy was successfully carried out. In the anatomopathological macroscopic study a 14 cm-multi-cystic neoformation was seen and a solid tumour was discovered at the head of the pancreas that infiltrated the wall of the duodenum. In the longitudinal cross-section of the pancreatic body the MPD was seen to be severely dilated. A focal adenocarcinoma in a intraductal papillary mucinous neoplasm (IPMN) was finally diagnosed. Pancreatic lesions are usually asymptomatic and are detected by chance during other imaging tests. The IPMN rates of malignancy have been reported of between 19 to 30%. The management of pancreatic cystic lesions still represents a clinical challenge. As always, the multi-disciplinary management is mandatory in this type of tumour.

An Unusual Case of Desmoplastic Melanoma With Monster Cells Imitating an Atypical Fibroxanthoma.

Numerous cells with very large and irregular nuclei ("monster" cells) have not hitherto been reported in desmoplastic melanoma (DM). Their prognostic significance in melanomas is a matter of debate, although some authors have associated them with more aggressive tumor behavior. We report a mixed DM on the scalp of an 88-year-old woman imitating an atypical fibroxanthoma. Tumor cells stained positive for SOX10, S100, and cyclin D1; BRAF mutation status was negative, and fluorescence in situ hybridization analysis showed copy number gains in 11q13 (cyclin D1) and 6p25 (RREB1), and loss in 6q23 (MYB). Cyclin D1 amplification is associated with poor prognosis in melanoma.

Mitotic count: A need for standardization / Recuento mitótico: una necesidad de estandarización

PURPOSE: The mitotic count (MC), number of mitosis per unit area, is a very important parameter frequently used for classification and grading of some tumors. Traditionally, the MC has been expressed in terms of number of mitoses per high power field. The size of the field of view can vary greatly among different microscopes. In order to avoid under or overestimation of mitotic count, a conversion needs to be made. METHODS: A simple formula based on a simple rule of three has been devised to standardize the mitotic count to the reference area by multiplying the number of mitotic figures by a correction factor which has been calculated for the most frequently used microscopes and various common tumors. RESULTS AND CONCLUSIONS: We propose this simple method, which involves only a single multiplication, to standardize the mitotic count to the reference area

OBJETIVO: El recuento mitótico o número de mitosis por unidad de área, es un parámetro muy importante utilizado frecuentemente para clasificar y estadificar ciertos tumores. Tradicionalmente se ha expresado el recuento mitótico en términos de número de mitosis por campos de alta frecuencia. El tamaño del campo de visión puede variar ampliamente entre los diferentes microscopios. A fin de evitar la infraestimación o sobreestimación del recuento mitótico, debe realizarse una conversión. MÉTODOS: Por medio de una simple regla de tres, se ha obtenido una fórmula simple para estandarizar el recuento mitótico. Multiplicando el número de mitosis por un factor de corrección, se obtiene el recuento mitótico estandarizado al área de referencia. Se han calculado los factores de corrección para los microscopios más habituales y para los diferentes tumores comunes. RESULTADOS Y CONCLUSIONES: Proponemos este método simple (únicamente uno por multiplicación) para estandarizar el recuento mitótico con respecto al área de referencia

Mitotic count: A need for standardization.

PURPOSE: The mitotic count (MC), number of mitosis per unit area, is a very important parameter frequently used for classification and grading of some tumors. Traditionally, the MC has been expressed in terms of number of mitoses per high power field. The size of the field of view can vary greatly among different microscopes. In order to avoid under or overestimation of mitotic count, a conversion needs to be made. METHODS: A simple formula based on a simple rule of three has been devised to standardize the mitotic count to the reference area by multiplying the number of mitotic figures by a correction factor which has been calculated for the most frequently used microscopes and various common tumors. RESULTS AND CONCLUSIONS: We propose this simple method, which involves only a single multiplication, to standardize the mitotic count to the reference area.

[Nested variant Transitional Cell Carcinoma. Report of two cases and bibliographic review.] / El carcinoma urotelial variante en nidos(NESTED). Presentación de dos casos y revisión de la literatura.

OBJECTIVE: Nested type transitional cell carcinoma of the bladder is a rare histological variant among bladder tumors. Although clinical presentation is similar to the other bladder tumors, its macroscopic appearance may be equivocally benign, with submucosal growing which is difficult to detect on cystoscopy, so that diagnosis may be delayed. METHODS: We present the characteristics of nested type transitional cell carcinoma and review the differential diagnosis for this entity with possible counterfeiters. RESULTS: In this article, we report two cases of nested type transitional cell carcinoma that presents, in one of them, all three growing patterns. CONCLUSIONS: Microscopically nested transitional cell carcinoma is characterized by a cell distribution forming nests and tubules. They generally present low cytologic atypia simulating a low grade urothelial carcinoma, or benign bladder lesions such as von Brunn nests or nefrogenic adenoma.

El carcinoma urotelial variante en nidos (NESTED). Presentación de dos casos y revisión de la literatura / Nested variant Transitional Cell Carcinoma. Report of two cases and bibliographic review

OBJETIVO: El carcinoma urotelial de vejiga tipo "nested" o en nidos es una variante histológica rara dentro de los tumores uroteliales de vejiga. Aunque las manifestaciones clínicas son semejantes a los demás tumores de vejiga, su apariencia macroscópica puede ser equívocamente benigna, con crecimiento submucoso difícil de detectar en la cistoscopia, lo que puede retrasar el diagnóstico. MÉTODO: presentamos las características del carcinoma urotelial variante tipo nested y revisamos los diagnósticos diferenciales de esta entidad con sus posibles imitadores. RESULTADO: En este trabajo presentamos dos casos de carcinoma urotelial tipo nested que presentan, en uno de los casos, los tres patrones de crecimiento. CONCLUSIONES: Microscópicamente el carcinoma urotelial nested se caracteriza por la distribución celular en forma de nidos y túbulos. Generalmente presentan poca atipia citológica que simula un carcinoma urotelial de bajo grado, o lesiones vesicales benignas como los nidos de von Brunn o los adenomas nefrogénicos

OBJECTIVE: Nested type transitional cell carcinoma of the bladder is a rare histological variant among bladder tumors. Although clinical presentation is similar to the other bladder tumors, its macroscopic appearance may be equivocally benign, with submucosal growing which is difficult to detect on cystoscopy, so that diagnosis may be delayed. METHODS: We present the characteristics of nested type transitional cell carcinoma and review the differential diagnosis for this entity with possible counterfeiters. RESULTS: In this article, we report two cases of nested type transitional cell carcinoma that presents, in one of them, all three growing patterns. CONCLUSIONS: Microscopically nested transitional cell carcinoma is characterized by a cell distribution forming nests and tubules. They generally present low cytologic atypia simulating a low grade urothelial carcinoma, or benign bladder lesions such as von Brunn nests or nefrogenic adenoma

Planos conjugados y sistema de iluminación de Köhler en microscopía óptica / Conjugate planes and Köhler illumination in optical microscopy

Un adecuado conocimiento y comprensión del concepto de planos conjugados es de capital importancia en la utilización del microscopio por cuanto que desde hace ya bastante tiempo el diseño de los microscopios se basa en la correcta situación de sus dos conjuntos de planos conjugados. En 1893 August Köhler publicó el trabajo «Un nuevo sistema de iluminación en microfotografía» donde dio a conocer los fundamentos básicos de una técnica de iluminación que actualmente lleva su nombre. El conocimiento y aplicación de los principios del sistema de iluminación de Köhler constituye el elemento de mayor importancia en el correcto manejo de un microscopio. Dichos principios no siempre son bien conocidos y comprendidos por los usuarios del microscopio constituyendo una fuente frecuente de errores en microscopía, particularmente en microfotografía. En este artículo revisamos los principios básicos del concepto de planos conjugados y del sistema de iluminación de Köhler (AU)

Adequate knowledge and understanding of the concept of conjugate planes is of paramount importance in the use of the microscope and for a long time microscope design was based on the correct location of the two sets of conjugate planes. In 1893 August Köhler published the article «A new illumination system in microphotography» in which he introduced the basics of an illumination technique that now bears his name. The knowledge and application of the principles of the Köhler illumination system is the most important element in the proper handling of a microscope. These principles are not always well known or understood by the users of microscopes, frequently leading to errors in microscopy, particularly in photomicrography. This article reviews the basic principles of the concept of conjugate planes and Köhler illumination system (AU)