A novel in-vitro model of intervertebral disc degeneration using hyperphysiological loading.

Intervertebral disc (IVD) degeneration includes changes in tissue biomechanics, physical attributes, biochemical composition, disc microstructure, and cellularity, which can all affect the normal function of the IVD, and ultimately may lead to pain. The purpose of this research was to develop an in-vitro model of degeneration that includes the evaluation of physical, biomechanical, and structural parameters, and that does so over several load/recovery periods. Hyperphysiological loading was used as the degenerative initiator with three experimental groups employed using bovine coccygeal IVD specimens: Control; Single-Overload; and Double-Overload. An equilibrium stage comprising a static load followed by two load/recovery periods was followed by six further load/recovery periods. In the Control group all load/recovery periods were the same, comprising physiological cyclic loading. The overload groups differed in that hyperphysiological loading was applied during the 4th loading period (Single-Overload), or the 4th and 5th loading period (Double-Overload). Overloading led to a significant reduction in disc height compared to the Control group, which was not recovered in subsequent physiological load/recovery periods. However, there were no significant changes in stiffness. Overloading also led to significantly more microstructural damage compared to the Control group. Taking all outcome measures into account, the overload groups were evaluated as replicating clinically relevant aspects of moderate IVD degeneration. Further research into a potential dose-effect, and how more severe degeneration can be replicated would provide a model with the potential to evaluate new treatments and interventions for different stages of IVD degeneration.

In-vitro models of disc degeneration - A review of methods and clinical relevance.

The intervertebral disc (IVD) provides flexibility, acts as a shock absorber, and transmits load. Degeneration of the IVD includes alterations in the biomechanics, extracellular matrix (ECM), and cellular activity. These changes are not always perceived, however, IVD degeneration can lead to severe health problems including long-term disability. To understand the pathogenesis of IVD degeneration and suitable testing methods for emerging treatments and therapies, this review documents in-vitro models of IVD degeneration including physical disruption, hyperphysiological loading, ECM degradation by enzyme digestion, or a combination of these methods. This paper reviews and critically analyses the models of degeneration published since the year 2000 in either in human or animal specimens. The results are categorised in terms of the IVD biomechanics, physical attributes, ECM composition, tissue damage and cellularity to evaluate the models with respect to natural human degeneration, and to provide recommendations for clinically relevant models for the various stages of degeneration. There is no one model that replicates the wide range of degenerative changes that occur as part of normal degeneration. However, cyclic overloading replicates many aspects of degeneration, with the advantage of a dose-response allowing the tuning of damage initiated. Models of severe degeneration are currently lacking, but there is potential that combining cyclic overloading and enzymatic digestion will provide model that closely resembles human IVD degeneration. This will provide an effective way to investigate the effects of severe degeneration, and the evaluation of treatments for the IVD, which would generally be indicated at this advanced stage of degeneration.

Impact of an intervention for reducing waste through educational strategy: A Mexican case study, what works, and why?

Generation and inadequate management of solid waste constitute a global challenge. Projections for 2050 portend an annual increase of 3.40 billion tons of waste. This study assessed the impact of an environmental education intervention (EEI) aimed at reducing waste generation and fomenting pro-environmental behaviors in an academic public-health institution in Mexico. The EEI was implemented over 20 months using a model of behavior change. Using a mixed-method design (QUAN + qual), baseline and follow-up measurements were performed through electronic questionnaires (n = 754), focus groups (n = 20), and waste quantification. A double-difference model was performed to measure pro-environmental behaviors impact: overall and by sex, age, educational level and function within the institution. Waste quantification was performed using a quartering method and weekly monitoring. The qualitative data were studied through thematic analysis. As a result of the EEI, women reduced their use of multilayer packaging (-15.6 pp, p < 0.05) and frequent use of non-ecological materials (-17.6 pp, p < 0.05). Graduate-level participants reduced their regular and frequent use of these materials (-33.3 pp, p < 0.05, 27.6 pp, p < 0.01), while those with lower educational levels increased their ecological behavior at home (12.1 pp, p < 0.05). Waste generation dropped by 60.1% vis-a-vis the baseline measurement. Our qualitative findings showed a relationship between holding a position of power in the institution and recycling. They also revealed that available infrastructure for separating waste contributed substantially to the observed impact. With actions centered on physical structure, community practice and institutional policy components, the EEI improved the pro-environmental behaviors and perceptions of participants.

The mutagenesis of a type IV secretion system locus of Piscirickettsia salmonis leads to the attenuation of the pathogen in Atlantic salmon, Salmo salar.

Piscirickettsiosis is a threatening infectious disease for the salmon industry, due to it being responsible for significant economic losses. The control of outbreaks also poses considerable environmental challenges. Despite Piscirickettsia salmonis having been discovered as the aetiological agent of the disease more than 25 years ago, its pathogenicity remains poorly understood. Among virulence factors identified so far, type four secretion systems (T4SS) seem to play a key role during the infection caused by the bacterium. We report here the genetic manipulation of P. salmonis by means of the transference of plasmid DNA in mating assays. An insertion cassette was engineered for targeting the icmB gene, which encodes a putative T4SS-ATPase and is carried by one of the chromosomal T4SS clusters found within the genome of P. salmonis PM15972A1, a virulent representative of the EM-90-like strain. The molecular characterization of the resulting mutant strain demonstrated that the insertion interrupted the target gene. Further in vitro testing of the icmB mutant showed a dramatic drop in infectivity as tested in CHSE-214 cells, which is in agreement with its attenuated behaviour observed in vivo. Altogether, our results demonstrate that, similar to other facultative intracellular pathogens, P. salmonis' virulence relies on an intact T4SS.

Postnatal nutritional treatment of neurocognitive deficits in fetal alcohol spectrum disorder.

Ethanol is the most important teratogen agent in humans. Prenatal alcohol exposure can lead to a wide range of adverse effects, which are broadly termed as fetal alcohol spectrum disorder (FASD). The most severe consequence of maternal alcohol abuse is the development of fetal alcohol syndrome, defined by growth retardation, facial malformations, and central nervous system impairment expressed as microcephaly and neurodevelopment abnormalities. These alterations generate a broad range of cognitive abnormalities such as learning disabilities and hyperactivity and behavioural problems. Socioeconomic status, ethnicity, differences in genetic susceptibility related to ethanol metabolism, alcohol consumption patterns, obstetric problems, and environmental influences like maternal nutrition, stress, and other co-administered drugs are all factors that may influence FASD manifestations. Recently, much attention has been paid to the role of nutrition as a protective factor against alcohol teratogenicity. There are a great number of papers related to nutritional treatment of nutritional deficits due to several factors associated with maternal consumption of alcohol and with eating and social disorders in FASD children. Although research showed the clinical benefits of nutritional interventions, most of work was in animal models, in a preclinical phase, or in the prenatal period. However, a minimum number of studies refer to postnatal nutrition treatment of neurodevelopmental deficits. Nutritional supplementation in children with FASD has a dual objective: to overcome nutritional deficiencies and to reverse or improve the cognitive deleterious effects of prenatal alcohol exposure. Further research is necessary to confirm positive results, to determine optimal amounts of nutrients needed in supplementation, and to investigate the collective effects of simultaneous multiple-nutrient supplementation.

Clinical and mutational features of X-linked agammaglobulinemia in Mexico.

X-linked agammaglobulinemia (XLA) is caused by BTK mutations, patients typically show <2% of peripheral B cells and reduced levels of all immunoglobulins; they suffer from recurrent infections of bacterial origin; however, viral infections, autoimmune-like diseases, and an increased risk of developing gastric cancer are also reported. In this work, we report the BTK mutations and clinical features of 12 patients diagnosed with XLA. Furthermore, a clinical revision is also presented for an additional cohort of previously reported patients with XLA. Four novel mutations were identified, one of these located in the previously reported mutation refractory SH3 domain. Clinical data support previous reports accounting for frequent respiratory, gastrointestinal tract infections and other symptoms such as the occurrence of reactive arthritis in 19.2% of the patients. An equal proportion of patients developed septic arthritis; missense mutations and mutations in SH1, SH2 and PH domains predominated in patients who developed arthritis.

[Granulomatous appendicitis caused by sarcoidosis: report of one case]. / Apendicitis granulomatosa sarcoidal: una infrecuente entidad clínico-patológica. Caso clínico.

Granulomatous appendicitis is uncommon and can be caused by Crohn's disease, foreign body reactions, infections or sarcoidosis. We report a 26-year-old female consulting in the emergency room for pain in the right lower abdomen. She was released with analgesics and consulted 14 days later for the same pain. This time she was operated with the preoperative diagnosis of appendicitis. The pathological study of the surgical piece was compatible with a granulomatous appendicitis caused by sarcoidosis.

Curcumin prevents maleate-induced nephrotoxicity: relation to hemodynamic alterations, oxidative stress, mitochondrial oxygen consumption and activity of respiratory complex I.

The potential protective effect of the dietary antioxidant curcumin (120 mg/Kg/day for 6 days) against the renal injury induced by maleate was evaluated. Tubular proteinuria and oxidative stress were induced by a single injection of maleate (400 mg/kg) in rats. Maleate-induced renal injury included increase in renal vascular resistance and in the urinary excretion of total protein, glucose, sodium, neutrophil gelatinase-associated lipocalin (NGAL) and N-acetyl ß-D-glucosaminidase (NAG), upregulation of kidney injury molecule (KIM)-1, decrease in renal blood flow and claudin-2 expression besides of necrosis and apoptosis of tubular cells on 24 h. Oxidative stress was determined by measuring the oxidation of lipids and proteins and diminution in renal Nrf2 levels. Studies were also conducted in renal epithelial LLC-PK1 cells and in mitochondria isolated from kidneys of all the experimental groups. Maleate induced cell damage and reactive oxygen species (ROS) production in LLC-PK1 cells in culture. In addition, maleate treatment reduced oxygen consumption in ADP-stimulated mitochondria and diminished respiratory control index when using malate/glutamate as substrate. The activities of both complex I and aconitase were also diminished. All the above-described alterations were prevented by curcumin. It is concluded that curcumin is able to attenuate in vivo maleate-induced nephropathy and in vitro cell damage. The in vivo protection was associated to the prevention of oxidative stress and preservation of mitochondrial oxygen consumption and activity of respiratory complex I, and the in vitro protection was associated to the prevention of ROS production.

Apendicitis granulomatosa sarcoidal: una infrecuente entidad clínico-patológica. Caso clínico / Granulomatous appendicitis caused by sarcoidosis: Report of one case

Granulomatous appendicitis is uncommon and can be caused by Crohn's disease, foreign body reactions, infections or sarcoidosis. We report a 26-year-old female consulting in the emergency room for pain in the right lower abdomen. She was released with analgesics and consulted 14 days later for the same pain. This time she was operated with the preoperative diagnosis of appendicitis. The pathological study of the surgical piece was compatible with a granulomatous appendicitis caused by sarcoidosis.

Genomic-enabled prediction with classification algorithms.

Pearson's correlation coefficient (ρ) is the most commonly reported metric of the success of prediction in genomic selection (GS). However, in real breeding ρ may not be very useful for assessing the quality of the regression in the tails of the distribution, where individuals are chosen for selection. This research used 14 maize and 16 wheat data sets with different trait-environment combinations. Six different models were evaluated by means of a cross-validation scheme (50 random partitions each, with 90% of the individuals in the training set and 10% in the testing set). The predictive accuracy of these algorithms for selecting individuals belonging to the best α=10, 15, 20, 25, 30, 35, 40% of the distribution was estimated using Cohen's kappa coefficient (κ) and an ad hoc measure, which we call relative efficiency (RE), which indicates the expected genetic gain due to selection when individuals are selected based on GS exclusively. We put special emphasis on the analysis for α=15%, because it is a percentile commonly used in plant breeding programmes (for example, at CIMMYT). We also used ρ as a criterion for overall success. The algorithms used were: Bayesian LASSO (BL), Ridge Regression (RR), Reproducing Kernel Hilbert Spaces (RHKS), Random Forest Regression (RFR), and Support Vector Regression (SVR) with linear (lin) and Gaussian kernels (rbf). The performance of regression methods for selecting the best individuals was compared with that of three supervised classification algorithms: Random Forest Classification (RFC) and Support Vector Classification (SVC) with linear (lin) and Gaussian (rbf) kernels. Classification methods were evaluated using the same cross-validation scheme but with the response vector of the original training sets dichotomised using a given threshold. For α=15%, SVC-lin presented the highest κ coefficients in 13 of the 14 maize data sets, with best values ranging from 0.131 to 0.722 (statistically significant in 9 data sets) and the best RE in the same 13 data sets, with values ranging from 0.393 to 0.948 (statistically significant in 12 data sets). RR produced the best mean for both κ and RE in one data set (0.148 and 0.381, respectively). Regarding the wheat data sets, SVC-lin presented the best κ in 12 of the 16 data sets, with outcomes ranging from 0.280 to 0.580 (statistically significant in 4 data sets) and the best RE in 9 data sets ranging from 0.484 to 0.821 (statistically significant in 5 data sets). SVC-rbf (0.235), RR (0.265) and RHKS (0.422) gave the best κ in one data set each, while RHKS and BL tied for the last one (0.234). Finally, BL presented the best RE in two data sets (0.738 and 0.750), RFR (0.636) and SVC-rbf (0.617) in one and RHKS in the remaining three (0.502, 0.458 and 0.586). The difference between the performance of SVC-lin and that of the rest of the models was not so pronounced at higher percentiles of the distribution. The behaviour of regression and classification algorithms varied markedly when selection was done at different thresholds, that is, κ and RE for each algorithm depended strongly on the selection percentile. Based on the results, we propose classification method as a promising alternative for GS in plant breeding.

Úlcera genital aguda de Lipschütz: caso clínico / Lipschütz acute genital ulcer: case report

La úlcera genital aguda (UGA) o úlcera de Lipschütz constituye una infrecuente entidad clínica caracterizada por la aparición de úlceras genitales en niñas y adolescentes que no han iniciado su actividad sexual. El cuadro es de inicio agudo, con formación de úlceras dolorosas habitualmente precedidas en su aparición por manifestaciones sistémicas tales como fiebre, cefalea, astenia, adinamia, mialgias y adenopatías inguinales, y donde el estudio microbiológico de la lesión descarta un posible origen infeccioso. A pesar de presentar un cuadro clínico característico, esta enfermedad constituye una entidad poco conocida y por tanto subdiagnosticada, motivo por el cual presentamos el caso de una paciente de 10 años con diagnóstico de UGA realizado en el Departamento de Dermatología de la Pontificia Universidad Católica de Chile.

Acute genital ulcer (AGU) or Lipschütz ulcer is a rare clinical entity characterized by the appearance of genital ulcers in children and adolescents who have not initiated sexual activity. The picture is of acute onset, with formation of painful ulcers on their occurrence usually preceded by systemic manifestations such as fever, headache, fatigue, weakness, muscle pain and inguinal lymphadenopathy, and where the microbiological study of injury rule out a possible infectious origin. Despite presenting a characteristic clinical picture, this disease is a little known entity and under diagnosed, we present the case of a 10 years old girl diagnosed with UGA conducted at the Department of Dermatology, Catholic University of Chile.

Cáncer gástrico perforado: estudio clínico-morfológico y pronóstico / Perforated gastric cancer

Background: Perforation is an unusual presentation of gastric cancer. There is disagreement about its prognosis and treatment. Aim: To describe the clinical, morphological, therapeutic and prognostic features of perforated gastric cancer. Material and Methods: Reviewing the registry of a pathology laboratory in a general hospital, 13 patients with perforated gastric cancer, aged 48 to 75 years and operated in a period of 20 years, was identified. The medical records of these patients were reviewed and eventual deaths were identified using death certificates. Results: A gastrectomy was performed in 9 cases and lymph node dissection in six. Seventy eight percent were T4 tumors and all patients in whom a lymph node dissection was done, had lymph node involvement. In 10 cases, the preoperative diagnoses were a perforated peptic ulcer. Mean global survival was six months. The figures for patients subjected or not subjected to gastrectomy were 21.5 and 3.7 months, respectively (p < 0.01). One of five patients subjected to emergency surgery, died. Conclusions: Perforation occurs usually in advanced stages of gastric cancer and older patients. In this report those patients subjected to gastrectomy have a better survival.

Introducción: El cáncer gástrico perforado (CGP) es una infrecuente forma de presentación de la enfermedad. Su pronóstico y manejo quirúrgico son motivo de controversias. El objetivo de este estudio es describir variables clínico-morfológicas de pacientes con CGP junto con valorar el tratamiento e impacto en la supervivencia (SV) de estos pacientes. Material y Método: Estudio de cohorte histórica. Se estudiaron variables clínico-morfológicas, de tratamiento y SV de pacientes con CGP sometidos a cirugía radical o paliativa en el Hospital Hernán Henríquez Aravena de Temuco entre enero de 1986 y diciembre de 2007 (n = 13). Utilizando los paquetes estadísticos Epi-info 6.0 y Stata 9.0, se aplicó estadística descriptiva, analítica y análisis de SV. Resultados: Se constató 13 casos de CGP (1,8 por ciento) con un promedio de edad de 64,2 años (35-75 años). Se efectuó gastrectomía en 9 pacientes (69 por ciento) en 6 de ellos con disección ganglionar. El 78 por ciento correspondió a tumores T4 y todos los casos con disección ganglionar presentaron compromiso de los linfonodos. En 10/13 el diagnóstico pre-operatorio fue úlcera péptica perforada (UPP) permitiendo los hallazgos intra-operatorios sospechar el carácter neoplásico maligno en 10/13 casos. El promedio de SVglobal fue 16 meses, siendo de 21,5 y 3,7 meses (p < 0,001) para el subgrupo sometido a gastrectomía y reparación respectivamente. La mortalidad quirúrgica en sujetos sometidos a gastrectomía de urgencia fue 20 por ciento (1/5). Conclusiones: La perforación gástrica se presenta habitualmente en pacientes mayores y con estadios avanzados de la enfermedad, nuestros pacientes gastrectomizados con intención curativa mostraron mejores resultados de supervivencia.

Neoplasia blástica de células dendríticas plasmocitoides: Caso clínico / Blastic plasmocytoid dendritic cell neoplasm: Report of one case

Background: We report a 74 years old male consulting for multiple painless non pruriginous pink plaques and nodules of truncal distribution that appeared 15 days earlier. A skin biopsy disclosed a blastic plasmocytoid dendritic cell neoplasm. A staging CAT scan showed lymphadenopathies located around the trachea and its bifurcation. A bone marrow biopsy did not show tumor infiltration. The patient has been treated with four cycles of cyclophosphamide-doxorubicin-vincristine-prednisone, obtaining a partial remission of the lesions.

Mucocele apendicular gigante: reporte de un caso y revisión de la literatura / Giant appendiceal mucocele: case report and review of the literature

El mucocele apendicular (MA) corresponde a una dilatación quística del lumen apendicular rellena por mucus en su interior; secundario a etiologías de naturaleza benigna (hiperplasia mucinosa y cistoadenoma) o maligna (cistoadenocarcinoma).Se trata de una condición infrecuente, reportándose en no más allá del 0,3 por ciento de las apendicectomías. Su tamaño y manifestaciones clínicas son extremadamente variables, permitiendo el estudio anatomo-patológico de la pieza quirúrgica establecer el diagnóstico etiológico. Presentamos el caso de un MA gigante secundario a un cistoadenoma mucinoso, diagnosticado en un hombre de 57 años en la Unidad de Anatomía Patológica del Hospital Hernán Henríquez Aravena de Temuco...

Appendiceal mucocele (AM) is a cystic dilatation of the appendiceal lumen filled by mucus inside, secondary to benign etiologies (hyperplasia and mucinous cystadenoma) or malignant (cystadenocarcinoma). This condition is uncommon, being reported in no more than 0.3 percent of appendectomies. Its size and clinical manifestations are extremely variable, allowing the pathological analysis of the surgical specimen etiologic diagnosis. We report a case of a giant AM secondary to a mucinous cystadenoma diagnosed in a 57-year-old man in the Pathology Unit of Hospital Hernán Henríquez Aravena of Temuco...

Siringoma vulvar: reporte de caso y revisión de la literatura / Vulvar syringoma: case report and literature review

Se presenta el caso de una mujer de 32 años, quien consultó por presentar desde hace 6 meses nódulos múltiples y pruriginosos en ambos labios mayores, prurito que se exacerbaba durante la menstruación. El estudio anatomo-patológico demostró una proliferación dérmica de conductos pequeños revestidos por una doble capa de células cuboídeas normotípicas, y rodeados por un estroma fibroso compatibes con un siringoma...

We report a case of a 32 year-old woman, who consulted to present for 6 months and multiple and itchy nodules in both labia majora, itching that was exacerbated during menstruation. The pathological study showed a dermal proliferation of small ducts lined by a double layer of normotipic cuboidal cells, and surrounded by a fibrous stroma compatibes a syringoma...

[Brain hydatidosis: report of four cases]. / Hidatidosis cerebral: aspectos clínicos e imagenológicos. Reporte de 4 casos.

In only 2% of all cases of hydatidosis, the cysts are located in the brain. We report a 12-year-old male, a 5-year-old girl and a 19-year-old female consulting for intracranial hypertension and a 13-year-old male consulting for a left hemiparesis. Imaging studies found intra-cerebral cysts with characteristics of hydatidosis in all. All lesions were completely removed surgically and the pathological study of the excised piece confirmed the diagnosis of hydatidosis.

Hamartoma de glándula peribiliar: reporte de dos casos / Peribiliar gland hamartoma: report of two cases

El hamartoma peribiliar (HPB) o adenoma de conductos biliares corresponde a un tumor hepático benigno, que representa tan solo el 1,3 por ciento de todos los tumores primarios del hígado. Macroscópicamente corresponde a una lesión redondeada bien delimitada, subcapsular, siendo habitualmente diagnosticado como un hallazgo intra-operatorio o de autopsia. Se presentan dos pacientes con diagnóstico incidental de HPB realizado en la Unidad de Anatomía Patológica del Hospital Hernán Henríquez de Temuco.

Peribiliary gland hamartoma (PGH) or bile duct adenoma corresponds to a benign liver tumor, which represents only 1.3 percent of all primary liver tumors. Corresponds to a macroscopically well-defined round lesion, subcapsular, and is usually diagnosed as an intra-operative findings or autopsy. We report two patients with incidental diagnosis of PGH conducted in the Pathology Unit of the Hospital Hernán Henríquez in Temuco.

Pericarditis constrictiva tuberculosa: reporte de un caso y revisión de la literatura / Tuberculous constrictive pericarditis: case report and literature review

La pericarditis tuberculosa (PT) representa una rara manifestación extrapulmonar de tuberculosis (TBC), que se encuentra en aproximadamente el 1 por ciento de las autopsias por TBC y 1-2 por ciento de casos de TBC pulmonar, estando su presentación estrechamente asociado con la infección por VIH. El compromiso pericárdico ocurre habitualmente por diseminación linfática retrógrada o diseminación hematógena desde un foco pulmonar primario, pudiendo clínicamente manifestarse como derrame pericárdico, pericarditis constrictiva o un patrón mixto. El presente trabajo, describe los hallazgos clínicos y morfológicos de un caso de PT en un sujeto inmunocompetente de 78 años, con diagnóstico de PT constrictiva efectuado en el Hospital Hernán Henríquez Aravena de Temuco.

Tuberculous pericarditis (TP) is a rare manifestation of extrapulmonary tuberculosis (TBC), found in approximately 1 percent of autopsies by TB and 1-2 percent of cases of pulmonary TB, while his presentation closely associated with the HIV infection. The pericardial involvement usually occurs by retrograde lymphatic spread or hematogenous spread from a primary pulmonary focus, which may clinically manifest as pericardial effusion, constrictive pericarditis or a mixed pattern. This paper describes the clinical and morphological findings of a TP case in an 78-year old immunocompetent patient, with constrictive TP diagnosed made in the Hospital Hernán Henríquez Aravena in Temuco.

Hiperplasia cutánea linfoide (Linfocitoma cutis) secundaria a fármacos: hallazgos clínicos y morfológicos / Cutaneous lymphoid hyperplasia (lymphocytoma cutis) due to drugs: clinical and morphological findings

Pseudolinfoma cutáneo es el término utilizado para indicar un grupo de trastornos linfoproliferativos benignos de la piel, siendo el linfocitoma cutis una forma de seudolinfoma de células B. Clínicamente se manifiesta como nódulos o placas solitarias, generalmente localizados en la cara de mujeres jóvenes. Su etiopatogenia estaría relacionada con una respuesta inmunológica local exagerada ante diversos desencadenantes tales como, picadura de insectos, acupuntura, vacunas, tatuajes, medicamentos e infecciones. Se presentan dos casos de pacientes con diagnóstico de linfocitoma cutis realizado en la Unidad de Anatomía Patológica del Hospital Hernán Henríquez de Temuco.

Cutaneous pseudolymphoma is the term used to indicate a group of benign lymphoproliferative disorders of the skin, being the cutaneous lymphomas a form of B-cell pseudolymphoma. Clinically it manifests as solitary nodules or plaques, usually located on the face of young women. Its pathogenesis could be related to an exaggerated local immune response to various causes such as insect bites, acupuncture, vaccinations, tattoos, drugs and infections. We present two cases of patients diagnosed with skin linfocitoma made in the Pathology Unit in Hernán Henríquez Hospital of Temuco.