[Solid pseudopapillary neoplasm. Report of three cases and review of the literature]. / Neoplasia sólida pseudopapilar. Reporte de tres casos y revisión de la literatura.

Background: Solid pseudopapillary neoplasm, or Frantz-Gruber tumor, is a diagnostic challenge for the surgical pathologist. It is classified by the WHO as a malignant epithelial tumor of the pancreas, its prevalence is low, it occurs in only 1 to 2% of all malignant tumors of the pancreas, it usually affects mainly young women, its origin is still unclear, it is generally It presents as a solitary, encapsulated lesion, without invasion of peripancreatic tissues with rare cases of metastasis, which is why it is considered a low-grade malignant tumor by the WHO. The objective of this article is to present three clinical cases and to evaluate the epidemiology, clinical manifestations, morphology and immunohistochemical expression of the tumor in a review of the bibliography, as well as to compare it with the cases already reported on the subject. Clinical case: Three cases of Frantz tumor were diagnosed by the pathology department of a tertiary hospital are presented, which correspond to two women aged 17 and 34, as well as a 52-year-old man whose presentation by age and sex is rare. Conclusions: After the bibliographical review and the analysis of the cases presented, we verified the difficulty to make a correct diagnosis, since its presence is rare in the daily practice of the surgical pathologist. The morphological patterns of the solid pseudopapillary tumor are varied and can often be reminiscent of neuroendocrine tumors of the pancreas, whose presentation rate is higher.

[Histological diagnosis of strongyloidiasis in the Medical Unit of High Specialty of Puebla]. / Diagnóstico histológico de estrongiloidiasis en la Unidad Médica de Alta Especialidad de Puebla.

Background: Strongyloides stercolaris is one of the most important intestinal nematodes due to its worldwide distribution. It's estimated that it affects 50 to 100 million people in 70 countries of the world. In a large percentage of cases it is asymptomatic, however, patients with immunosuppression may present more serious symptoms. The life cycle of this parasite comprises two phases: one as a free-living organism and the other as a parasite. The objective of this case report is to describe the histological findings compatible with this parasitosis and the importance of recognizing them in order to provide adequate and timely treatment. Case report: This is a 37-year-old male patient who began his condition in December 2018, with an acute respiratory condition that occurs after a diarrheal event. Due to the initial evolution, the presumptive diagnosis of Crohn's disease was made, treated with prednisone without showing improvement. During follow-up, stomach and duodenal biopsies were performed, among others, which allowed the detection of S. stercolaris, which was managed with ivermectin. Conclusions: The case presented agrees with what is referred to in the consulted literature, as it demonstrates the wide spectrum of clinical manifestations, the relationship with immunosuppression states and how frequent it is to make a first-instance erroneous diagnosis. Likewise, it exemplifies the difficulty involved in making the diagnosis of a parasitosis through histological study, due to the particularities of the parasite itself, as well as the little familiarity that the surgical pathologist may have due to how unusual this pathology is outside of tropical environments.

Introducción: Strongyloides stercolaris es uno de los nematodos intestinales de mayor importancia debido a su distribución mundial. Se estima que afecta a 50-100 millones de personas en 70 países del mundo. En un amplio porcentaje de los casos cursa de forma asintomática, pero los individuos con inmunosupresión pueden presentar cuadros más graves. El ciclo de vida de este parásito comprende dos fases: una como organismo de vida libre y otra como parásito. El objetivo del presente reporte de caso es describir los hallazgos histológicos compatibles con esta parasitosis y la importancia de reconocerlos con la finalidad de proporcionar un tratamiento adecuado y oportuno. Caso clínico: Varón de 37 años que inicia su padecimiento en diciembre de 2018, con un cuadro respiratorio agudo que se presenta posterior a un evento diarreico. Debido a la evolución que presentó inicialmente, se realizó el diagnóstico presuntivo de enfermedad de Crohn y fue tratado con prednisona, sin mostrar mejoría. Durante el seguimiento se realizaron, entre otras, biopsias de estómago y de duodeno, que permitieron la detección de S. stercolaris y fue manejado con ivermectina. Conclusiones: El caso presentado concuerda con lo referido en la literatura consultada, pues demuestra el amplio espectro de manifestaciones clínicas, la relación con estados de inmunosupresión y lo frecuente que es realizar un diagnóstico erróneo de primera instancia. Así mismo, ejemplifica la dificultad que implica el realizar el diagnóstico de una parasitosis mediante el estudio histológico, debido a las particularidades del propio parásito, así como por la poca familiaridad que puede tener el patólogo quirúrgico debido a lo inusual que es esta patología fuera de ambientes tropicales.

Author Correction: Temperature Chaos, Memory Effect, and Domain Fluctuations in the Spiral Antiferromagnet Dy.

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Temperature Chaos, Memory Effect, and Domain Fluctuations in the Spiral Antiferromagnet Dy.

The spiral antiferromagnetic phase of polycrystalline dysprosium between 140 K and the Néel temperature at 178 K and its domain wall (DW) dynamics were investigated using high-resolution ultrasonic spectroscopy. Two kinetic processes of quasi-static DW motion occur under non-isothermal and isothermal conditions. A "fast" process is proportional to the rate of the temperature change and results in a new category of anelastic phenomena: magnetic transient ultrasonic internal friction (IF). This IF, related to fast moving magnetic DWs, decays rapidly after interruptions of cooling/heating cycles. A second, "slow" kinetic process is seen as logarithmic IF relaxation under isothermal conditions. This second process is glass-like and results in memory and temperature chaos effects. Low-frequency thermal fluctuations of DWs, previously detected by X-ray photon correlation spectroscopy, are related to critical fluctuations with Brownian motion-like dynamics of DWs.

Magnetic Domain Walls and Macroscopic Magnetization-Related Elastic and Anelastic Effects during Premartensitic Transition in Ni2MnGa.

The temperature and field dependences of internal friction and Young´s modulus are studied using a high-resolution ultrasonic (90 kHz) technique in stoichiometric ferromagnetic Ni2MnGa shape memory alloy close to the premartensitic transformation temperature, TPM, in the demagnetized state and under moderate fields. Several new effects observed like an apparent Young´s modulus softening close to TPM under moderate fields, instead of the hardening outside this range, as well as existing controversies in the apparent elastic and anelastic properties of Ni2MnGa close to TPM are explained by microeddy and macroeddy current relaxations that to date have been disregarded.