Solitary fibrous tumor of the parapharyngeal space: report of 2 cases and a literature review.

The solitary fibrous tumor (SFT) is usually described as a lesion arising from the pleura. Rarely, it has been described in the parapharyngeal space (PS). This study aims to report two cases of SFT in the PS and to perform a literature review on this topic. Two patients undergoing surgical resection of a SFT in the PS, were reported. A literature review on SFT of the PS, was also performed. Two patients were analyzed. Both patients underwent surgical resection, followed by adjuvant radiotherapy, for SFT arising from the PS. The postoperative course was uneventful and both patients recovered well after the procedure. No recurrences were diagnosed during the followup. SFT of the PS is an infrequent entity. Surgical resection is the most used treatment, and adjuvant radiation should be considered in patients with recurrence risk factors or distant metastases.

Algoritmo para el diagnóstico integrado de los gliomas 2021. Nuestra experiencia / Algorithm for the integrated diagnosis of gliomas 2021. Our experience

Resumen La aplicación de las diferentes técnicas moleculares para el diagnóstico de los gliomas según la clasificación de la OMS, sigue sin estar al alcance de todos en nuestro país. Nuestro objetivo fue describir el protocolo diagnóstico desarrollado en función de los recursos disponibles, conforme con la clasificación vigente (2021). También, describir el perfil epidemiológico de los gliomas diagnosticados entre 2018-2021 en el Instituto Roffo y contrastarlo con la literatura. Se evaluó la mutación en IDH1-R132H, ATRX, el estado del 1p19q, CDKN2A, EGFR y del p53. Se incluyeron 94 pacientes, 53.2% fueron masculinos, con una edad promedio de 50.9 años. El diagnóstico más frecuente fue el de GB IDH1-no mutado (63.8%). Considerando únicamente a los gliomas grado 2 y 3, el astrocitoma difuso IDH1-Mutado/ATRX-Mutado/p53-sobreexpresado, grado 2 (11.7%) fue el más frecuente. En cuanto a su localización, el 67% de los tumores se ubicaron en el telencéfalo neocortical: 24.5% del total en el lóbulo frontal. En el 95.7% de los casos se arribó a un diagnóstico integrado concluyente siguiendo el algoritmo propuesto. Las características epidemiológicas coinciden con lo publicado en la literatura. La biología molecular nos permitió diferenciar nítidamente enfermedades que suponíamos emparentadas desde un punto de vista histológico, pero que observando su historia natural, su genética y su respuesta a tratamientos instaurados eran tumores distintos, aunque todos fueran llamados "gliomas". Los estándares internacionales no conciben su diagnóstico sin la biología molecular. No es aceptable que se siga diagnosticando únicamente con estándares histológicos. El algoritmo propuesto podría ser una alternativa viable y confiable.

Abstract The utilization of the different molecular techniques for the diagnosis of gliomas according to the WHO classification is still not available to everyone in our country. Our objective was to describe the diagnostic algorithm devel oped based on available resources, in accordance with the current classification (2021). Also, to describe the epidemiological profile of gliomas diagnosed between 2018-2021 at the Roffo Institute and compare it with the international literature. IDH1-R132H and ATRX mutation, as well as 1p19q status, CDKN2A, EGFR, and p53 were evaluated. 94 patients were included, 53.2% were male, with a mean age of 50.9 years. The most frequent diagnosis was GB IDH1-wild type (63.8%). Considering only grade 2 and 3 gliomas, diffuse astrocytoma IDH1- Mutated / ATRX-Mutated / p53-overexpressed, grade 2 (11.7%) was the most frequent diagnosis. Regarding their location, 67% of the tumors were located in the neocortical telencephalon: 24.5% of the total in the frontal lobe. In 95.7% of cases, a conclusive integrated diagnosis was reached following the proposed algorithm. The epidemiological characteristics coincide with what has been published in the literature. Molecular biology allowed us to clearly differentiate pathologies that we assumed were related from a histological point of view, but which, observing their natural history, their genetics and their response to established treatments were different tumors, although they were all called "gliomas". International standards do not conceive CNS tumor diagnosis without molecular biology. It is not acceptable to continue to diagnose only with histological standards. The proposed algorithm could be a viable and reliable alternative.

[Algorithm for the integrated diagnosis of gliomas 2021. Our experience]. / Algoritmo para el diagnóstico integrado de los gliomas 2021. Nuestra experiencia.

The utilization of the different molecular techniques for the diagnosis of gliomas according to the WHO classification is still not available to everyone in our country. Our objective was to describe the diagnostic algorithm developed based on available resources, in accordance with the current classification (2021). Also, to describe the epidemiological profile of gliomas diagnosed between 2018-2021 at the Roffo Institute and compare it with the international literature. IDH1-R132H and ATRX mutation, as well as 1p19q status, CDKN2A, EGFR, and p53 were evaluated. 94 patients were included, 53.2% were male, with a mean age of 50.9 years. The most frequent diagnosis was GB IDH1-wild type (63.8%). Considering only grade 2 and 3 gliomas, diffuse astrocytoma IDH1-Mutated / ATRX-Mutated / p53-overexpressed, grade 2 (11.7%) was the most frequent diagnosis. Regarding their location, 67% of the tumors were located in the neocortical telencephalon: 24.5% of the total in the frontal lobe. In 95.7% of cases, a conclusive integrated diagnosis was reached following the proposed algorithm. The epidemiological characteristics coincide with what has been published in the literature. Molecular biology allowed us to clearly differentiate pathologies that we assumed were related from a histological point of view, but which, observing their natural history, their genetics and their response to established treatments were different tumors, although they were all called "gliomas". International standards do not conceive CNS tumor diagnosis without molecular biology. It is not acceptable to continue to diagnose only with histological standards. The proposed algorithm could be a viable and reliable alternative.

La aplicación de las diferentes técnicas moleculares para el diagnóstico de los gliomas según la clasificación de la OMS, sigue sin estar al alcance de todos en nuestro país. Nuestro objetivo fue describir el protocolo diagnóstico desarrollado en función de los recursos disponibles, conforme con la clasificación vigente (2021). También, describir el perfil epidemiológico de los gliomas diagnosticados entre 2018-2021 en el Instituto Roffo y contrastarlo con la literatura. Se evaluó la mutación en IDH1-R132H, ATRX, el estado del 1p19q, CDKN2A, EGFR y del p53. Se incluyeron 94 pacientes, 53.2% fueron masculinos, con una edad promedio de 50.9 años. El diagnóstico más frecuente fue el de GB IDH1-no mutado (63.8%). Considerando únicamente a los gliomas grado 2 y 3, el astrocitoma difuso IDH1-Mutado/ATRX-Mutado/p53-sobreexpresado, grado 2 (11.7%) fue el más frecuente. En cuanto a su localización, el 67% de los tumores se ubicaron en el telencéfalo neocortical: 24.5% del total en el lóbulo frontal. En el 95.7% de los casos se arribó a un diagnóstico integrado concluyente siguiendo el algoritmo propuesto. Las características epidemiológicas coinciden con lo publicado en la literatura. La biología molecular nos permitió diferenciar nítidamente enfermedades que suponíamos emparentadas desde un punto de vista histológico, pero que observando su historia natural, su genética y su respuesta a tratamientos instaurados eran tumores distintos, aunque todos fueran llamados "gliomas". Los estándares internacionales no conciben su diagnóstico sin la biología molecular. No es aceptable que se siga diagnosticando únicamente con estándares histológicos. El algoritmo propuesto podría ser una alternativa viable y confiable.

Apoptotic regulator BCL-2 blockade as a potential therapy in classical Hodgkin Lymphoma.

The challenge in classical Hodgkin Lymphoma (cHL) management is the 30-40% of refractory/relapsed cases. AIMS: The aim of this work was to determine whether NIK and BCL-2 could be useful as prognosis biomarkers in cHL. In addition, we evaluated BCL-2 as a directed-therapy in cHL cell lines using venetoclax. MAIN METHODS: We evaluated NIK and BCL-2 expression in 112 untreated cHL patients' lymph-node biopsies by immunohistochemistry. cHL cell lines were treated with venetoclax alone or combined with vincristine or doxorubicin. Cell viability, metabolic activity and cell death were analyzed by trypan-blue exclusion method, MTS assay and FDA/IP staining respectively. KEY FINDINGS: No correlation between NIK or BCL-2 expression and the majority of the clinical parameters was found. Patients with ≥60% BCL-2+ HRS-cells had a shorter disease-free survival (DFS) and overall survival (OS) (p = 0.002, p = 0.02 respectively). A decision tree analysis, in a 30 patients subgroup, showed that patients with <60% NIK+ HRS-cells but with ≥60% BCL-2+ HRS-cells had a worse outcome in terms of DFS and OS. These parameters performed better as prognosis indicators as compared to the diagnosis bone marrow status. Human cHL cell lines U-H01, KM-H2, L1236, SUPHD1, L540 showed sensitivity to venetoclax. The co-treatment effect of venetoclax and vincristine or doxorubicin on cell viability was diverse depending on the cell line evaluated. SIGNIFICANCE: BCL-2 should be considered as a prognosis biomarker as well as a potential new therapeutic target in cHL. We report for the first time the cytotoxic effect of venetoclax in human cHL cell lines.

Mutational profile and EBV strains of extranodal NK/T-cell lymphoma, nasal type in Latin America.

Extranodal NK/T-cell lymphoma (ENKTL) is an Epstein-Barr virus (EBV) associated lymphoma, prevalent in Asia and Latin America. Studies in Asian cohorts have identified some recurrent gene mutations in ENKTL; however, the mutational landscape of ENKTL in Latin America is unknown. In this study, we investigated the mutational profile and EBV strains of 71 ENKTL cases from Latin America (42 from Mexico, 17 from Peru, and 12 from Argentina) and compared it with Asian cohorts. The mutational analysis was performed by next generation sequencing (NGS) using an Ion AmpliSeq™ custom panel covering for the most frequently mutated genes identified in ENKTL. STAT3 was the most frequent mutated gene (16 cases: 23%), followed by MSN (10 cases; 14%), BCOR (9 cases; 13%), DDX3X (6 cases; 8%), TP53 (6 cases; 8%), MGA (3 cases; 4%), JAK3 (2 cases; 3%), and STAT5B (1 case; 1%). Mutations in STAT3, BCOR, and DDX3X were nearly mutually exclusive, suggesting different molecular pathways involved in the pathogenesis of ENKTL; whereas mutations in MGA, MSN, and TP53 were concomitant with other mutations. Most cases (75%) carried Type A EBV without the 30-bp LMP1 gene deletion. The overall survival was significantly associated with serum LDH level, Eastern Cooperative Oncology Group (ECOG) performance status, International Prognostic Index (IPI) score, and therapy (p < 0.05), but not associated with any mutation, EBV strain or deletion in EBV LMP1 gene. In conclusion, mutational analysis of ENKTL from Latin America reveals frequent gene mutations leading to activation of the JAK-STAT pathway (25%), mostly STAT3. Compared to Asian cohorts, BCOR, DDX3X and TP53 mutations were also identified but with different frequencies. None of these mutations were associated with prognosis.

Individual patient risk of progression of urinary bladder papillary tumors estimated from biomarkers at initial transurethral resection of bladder tumor.

OBJECTIVE: To determine if individual, instead of group, patient progression risk could be predicted using p53, Ki67 and CK20 biomarker percentage values at initial transurethral resection of bladder tumor specimens. METHODS: This was an observational study where biomarkers were measured with no knowledge of tumor outcome. Initial bladder tumor specimens were classified as non-invasive and invasive to sub-epithelium (pT1). Percentages of stained biomarker cells were tested as progression predictors from non-invasive to pT1 and pT1 to pT2. Progression probability was correlated with biomarker percentages resulting in a regression equation. RESULTS: We studied 112 patients (median age = 67, range 37-91, males 83/112 (73%), with median follow-up of 39 months (range 1.7-140). Mean biomarker values were higher in stage pT1 than in non-invasive (all p < 0.001). Cut-off points separating progression from non-progression groups in stage pT1 were higher than in non-invasive for all biomarkers. Correlation R values for progression probability vs. biomarker percentages varied from 0.7 to 0.9 (all p < 0.001), regression slopes from 0.1 to 0.8 and intercepts from 11 to 35. A novel individual progression probability was calculated as the product of biomarker percentage of stained cells and slope, plus the prevalence-adjusted intercept. CONCLUSIONS: Identification of individual risk of progression in patients with non-muscle-invasive bladder tumors was possible using p53- and Ki67-derived progression probability using a regression equation. Combining biomarker-derived progression probability to tumor stage pT1 improves progression to pT2 predictive accuracy.

Transformación de teratoma en rabdomiosarcoma / Transformation of teratoma in rabdomiosarcoma

Los teratomas son tumores germinales malignos compuestos por dos o más capas de tejido, que ocasionalmente se transforman en estirpes con crecimiento agresivo. Se presenta el caso de un paciente de 29 años con un tumor germinal gonadal localizado en testículo, cuya evolución fue desfavorable por presentar transformación en un fenotipo correspondiente a un rabdomiosarcoma. La patología aquí descripta deviene del crecimiento diferencial de un componente ya existente en el tumor original o la transformación en un linaje somático que se hace dominante. Los tumores transformados como el del caso descripto son raros y presentan características diferentes de la mayoría de las neoplasias germinales respecto del comportamiento, el pronóstico y la sensibilidad a los tratamientos establecidos.

Teratomas are malign germ cell tumors composed of two or more tissue layers. When there is specific organ differentiation they are called mature teratoma. They rarely grow aggressively. We report the case of a 29 year-old man with a diagnosis of gonadal germ cell tumor whose evolution was unfavorable owing to transformation into a different phenotype corresponding to a rhabdomyosarcoma. This phenomenon occurs through differential growth of a single histological component of the original tumor or transformation of a somatic lineage that becomes dominant. Transformed tumors such as the one herein described differ from most germ cell neoplasms regarding behavior, prognosis, and susceptibility to established treatments.

[Transformation of teratoma in rabdomiosarcoma]. / Transformación de teratoma en rabdomiosarcoma.

Teratomas are malign germ cell tumors composed of two or more tissue layers. When there is specific organ differentiation they are called mature teratoma. They rarely grow aggressively. We report the case of a 29 year-old man with a diagnosis of gonadal germ cell tumor whose evolution was unfavorable owing to transformation into a different phenotype corresponding to a rhabdomyosarcoma. This phenomenon occurs through differential growth of a single histological component of the original tumor or transformation of a somatic lineage that becomes dominant. Transformed tumors such as the one herein described differ from most germ cell neoplasms regarding behavior, prognosis, and susceptibility to established treatments.

Molecular Epidemiology of ALK Rearrangements in Advanced Lung Adenocarcinoma in Latin America.

OBJECTIVE: Latin American countries are heterogeneous in terms of lung cancer incidence and exposure to potential carcinogens. We evaluated the frequency and clinical characteristics of ALK rearrangements (ALKr) in Latin America. METHODS: A total of 5,130 lung cancer patients from 10 Latin American countries were screened for inclusion. ALKr detection was performed by fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) to assess method variability. Demographic and clinicopathologic characteristics were analyzed. RESULTS: Among the 5,130 patients screened, 8.4% (n = 433) had nonevaluable FISH tests. Evaluable FISH analyses revealed positive ALKr in 6.8% (320/4,697) of the study population, which included patients from 9 countries. ALKr distribution for each country was: Mexico 7.6% (79/1,034), Colombia 4.1% (10/242), Argentina 6.0% (153/2,534), Costa Rica 9.5% (13/137), Panama 4.4% (5/114), Uruguay 5.4% (2/37), Chile 8.6% (16/185), Venezuela 8.9% (13/146), and Peru 10.8% (29/268). RT-PCR showed high positive (83.6%) and negative (99.7%) predictive values when compared to the gold standard FISH. In contrast, IHC only showed a high negative predictive value (94.6%). CONCLUSIONS: Although there is a clear country and continental variability in terms of ALKr frequency, this difference is not significant and the overall incidence of ALKr in Latin America does not differ from the rest of the world.

Sarcoma de la arteria pulmonar / Pulmonary Artery Sarcoma

El sarcoma de la arteria pulmonar es una patología rara y de pronóstico letal. Se desconoce su etiología, pero con mayor frecuencia afecta al tronco de la arteria pulmonar y a sus ramas principales. Los estudios complementarios mediante resonancia magnética con gadolinio y tomografía por emisión de positrones son de utilidad para orientar el diagnóstico, pero este sólo se puede establecer al realizar un estudio histológico. Presentamos este caso dada la baja incidencia y su importancia para el diagnóstico diferencial del tromboembolismo pulmonar.

Pulmonary artery sarcoma is a rare tumor with lethal prognosis. Its etiology is unknown; most frequently the pulmonary trunk and its main branches are affected. Magnetic resonance imaging with gadolinium and positron emission tomography are complementary studies that can guide the diagnosis, but this can only be established with the histological study. We present this case because of the low incidence and its importance in the differential diagnosis of pulmonary thromboembolism.

Soft tissue metastases from differentiated thyroid cancer diagnosed by ¹8F FDG PET-CT.

Distant metastases of differentiated thyroid cancer are unusual; lung and bones are the most frequently affected sites. Soft tissue metastases (STM) are extremely rare. We describe two cases of patients with differentiated thyroid cancer metastasizing to soft tissues. Both patients had widespread metastatic disease; clinically asymptomatic soft tissue metastases were found by ¹8-Fluordeoxyglucose positron emission tomography/computed tomography (¹8F FDG PET-CT), and confirmed by cytological and/or histopathological studies. These findings underscore the ability of ¹8F FDG PET-CT in accurately assessing the extent of the disease, as well as the utility of the method to evaluate regions of the body that are not routinely explored.

Soft tissue metastases from differentiated thyroid cancer diagnosed by 18F FDG PET-CT / Metástases em tecidos moles de câncer de tireoide diagnosticadas por 18F FDG PET-CT

Distant metastases of differentiated thyroid cancer are unusual; lung and bones are the most frequently affected sites. Soft tissue metastases (STM) are extremely rare. We describe two cases of patients with differentiated thyroid cancer metastasizing to soft tissues. Both patients had widespread metastatic disease; clinically asymptomatic soft tissue metastases were found by 18-Fluordeoxyglucose positron emission tomography/computed tomography (18F FDG PET-CT), and confirmed by cytological and/or histopathological studies. These findings underscore the ability of 18F FDG PET-CT in accurately assessing the extent of the disease, as well as the utility of the method to evaluate regions of the body that are not routinely explored.

As metástases a distância em carcinoma diferenciado de tireoide são raras. Pulmão e ossos são os lugares mais frequentemente atingidos. As metástases em tecidos moles são extremamente infrequentes. Neste artigo, descrevemos dois casos de pacientes com câncer diferenciado de tireoide com metástases em tecidos moles. Ambos os pacientes padeciam de enfermidade avançada. As metástases em partes moles foram assintomáticas e detectadas mediante 18-Fluordeoxyglucose positron emission tomography/computed tomography (18F FDG PET-CT), sendo confirmadas por citologia e/ou histopatologia. Esses achados ressaltam o valor do 18F FDG PET-CT para a avaliação correta da extensão da enfermidade e a utilidade do método para avaliar regiões do corpo que não são exploradas nos estudos de rotina.

[Orbital and ocular adnexal lymphomas. Clinico-pathological correlation in 25 cases]. / Linfomas de la órbita y anexos oculares. Correlación clínico patológica de 25 casos.

Clinical, histological features and outcome of a cohort of patients with orbital and adnexal lymphoproliferative tumors were evaluated. Twenty-five cases in an oncologic referral center from 1995 to 2008, were included in the study. Each case had detailed immunophenotypic analysis using a panel of monoclonal antibodies (CD45, CD20, CD3, CD5, CD23, BCL2, BCL6, BCL10, Ki67, CD30, CD15, BCL1, Kappa, Lambda, CD138). Lesions were classified by using WHO (2008) lymphomas classification. Twenty-three patients were found to have primary and two secondary lymphomas. Histological subtypes were: 16 patients with marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (MALT) lymphoma, four diffuse large B cell lymphomas, two mantle cell lymphomas, two follicular lymphomas, and one Hodgkin lymphoma. Among the 25 patients studied, 22 had localized stage. Extranodal marginal zone lymphoma was the most frequent type of primary orbital and adnexal lymphoma. In this study localized disease was observed in most cases, and distant spread of the lymphomas was infrequent.

Linfomas de la órbita y anexos oculares: Correlación clínico patológica de 25 casos / Orbital and ocular adnexal lymphomas: Clinico-pathological correlation in 25 cases

Se evaluaron las características clínicas, histológicas y la evolución de una cohorte de pacientes con linfomas de la órbita y anexos oculares. Entre 1995 y 2008 se estudiaron 25 casos de linfomas de la órbita y anexos oculares en un centro oncológico de referencia. En cada caso se analizó el inmunofenotipo usando un panel de anticuerpos monoclonales (CD45, CD20, CD3, CD5, CD23, BCL2, BCL6, BCL10, Ki67, CD30, CD15, BCL1, Kappa, Lambda, CD138). Las lesiones fueron evaluadas utilizando el sistema de clasificación de linfomas (OMS, 2008). Se analizaron 23 linfomas primarios y dos secundarios. Los subtipos histológicos fueron: 16 linfomas B de la zona marginal asociados a las mucosas (MALT), cuatro linfomas difusos de células grandes B, dos linfomas foliculares y un paciente con linfoma Hodgkin. De los 25 casos estudiados, 22 presentaron estadios localizados. El linfoma MALT fue el subtipo más frecuente. En este estudio se observó enfermedad localizada en la mayoría de los casos y con baja progresión a distancia.

Clinical, histological features and outcome of a cohort of patients with orbital and adnexal lymphoproliferative tumors were evaluated. Twenty-five cases in an oncologic referral center from 1995 to 2008, were included in the study. Each case had detailed immunophenotypic analysis using a panel of monoclonal antibodies (CD45, CD20, CD3, CD5, CD23, BCL2, BCL6, BCL10, Ki67, CD30, CD15, BCL1, Kappa, Lambda, CD138). Lesions were classified by using WHO (2008) lymphomas classification. Twenty-three patients were found to have primary and two secondary lymphomas. Histological subtypes were: 16 patients with marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (MALT) lymphoma, four diffuse large B cell lymphomas, two mantle cell lymphomas, two follicular lymphomas, and one Hodgkin lymphoma. Among the 25 patients studied, 22 had localized stage. Extranodal marginal zone lymphoma was the most frequent type of primary orbital and adnexal lymphoma. In this study localized disease was observed in most cases, and distant spread of the lymphomas was infrequent.

Neoplasia hematodérmica CD4+ CD56+ en la infancia / Hematodermic CD4+ CD56+ neoplasm in childhood

La neoplasia hematodérmica CD4+ CD56+ con fenotipo de célula dendrítica plasmocitoide es una rara y agresiva neoplasia recientemente reconocida por la WHO-EORTC classification. Afecta adultos de edad media y ancianos, siendo muy pocos los casos descriptos en niños. Presentamos el caso de una niña de 12 años con grave retraso mental, estigmas genéticos y múltiples lesiones cutáneas localizadas en miembros inferiores y superiores. Histológicamente se observó un infiltrado dérmico difuso de células pequeñas y medianas con expresión de CD4, CD56, CD43 y S100 así como de marcadores dendríticos plasmocitoides: CD 123 y BDCA-2 confirmados por citometría de flujo, sin compromiso de sangre periférica ni médula ósea. Cumpliendo dos semanas de tratamiento para leucemia linfoblástica aguda evolucionó con remisión clínica de las lesiones cutaneas.

Hematodermic CD4+ CD56+ neoplasm with plasmacytoid dendritic cell phenotype is a rare and aggressive neoplasm recently recognized by the WHO-EORTC classification. It generally appears in elderly adults, exceptionally in childhood. We present a 12-year-old girl with severe mental retardation, genetic clinical features and multiple nodular cutaneous lesions on legs and arms. Histologically the nodules showed diffuse dermal infiltrate of medium and small cells and expression of CD4, CD56, CD43, S100 and plasmacytoid dendritic markers: CD123, BDCA-2 under flow cytometry study. Peripheral blood and bone marrow were not involved. Clinical remission of cutaneous lesions was observed after two weeks of acute lymphoblastic leukemia therapy.

Enfermedad de Paget extramamaria primaria de escroto / Primary scrotal extramammary Paget's disease

Presentamos un caso de enfermedad de Paget extramamaria (EPEM) en un varón de 78 años de edad. Clínicamente se presentó una lesión nodular a nivel del escroto no dolorosa. El examen histológico reveló una formación tumoral compuesta por células epiteliales con amplio citoplasma eosinófilo y núcleo vesiculoso, que conformaban estructuras ductales localizadas en la unión dermoepidérmica y dermis superficial. Focalmente penetraban en la epidermis subrayacente. La resección quirúrgica fue el tratamiento de elección

[Signet ring cell lymphoma mimicking mucin-producing carcinoma]. / Linfoma de células en anillo de sello que simula carcinoma mucosecretante.

Signet ring cell lymphoma is a rare neoplasm characterized by large, vacuolated and clear cells mimicking mucin-producing adenocarcinoma. It is localized in nodal and extranodal sites. A case of a 59 years old male, with a diffuse lymphoma signet ring cell type localized on oropharyngeal mucosa is reported. The histopathology study showed signet ring cells and the immunophenotype was: vimentine(+), CD45(+), CD20(+), Ig M(+), Kappa chain(+) and high index proliferative activity of neoplastic cells (Ki 67:70%). After a review of the literature and previous reports, we could not find a similar case in this anatomic site. The patient had a unfavourable clinical course and died two months after the diagnosis without receiving any treatment.

Calcifilaxis en un paciente sometido a hemodiálisis: factores de riesgo asociados y revisión bibliográfica / Claciphylaxis in a hemodialysed patient: associated risk factors. Literature review

La calcifilaxis es una condición poco frecuente de calcificación diseminada en los tejidos y vasos sanguíneos dérmicos, que se acompaña de daño vascular oclusivo-trombótico y necrosis isquémica. Afecta principalmente vasos de pequeño y mediano calibre, conduciendo a lesiones eritemato-violáceas en la piel con posterior formación de úlceras, cuya infección secundaria y sepsis pueden llevar a la muerte. Se asocia mayormente con anomalías en el metabolismo fosfato-cálcico e hiperparatiroidismo en pacientes con falla renal crónica. Sin embargo, éstas anomalías no parecen ser fundamentales para explicar la fisiopatología de la enfermedad que aún resulta controvertida

Tumores mixtos apocrinos de la piel: comunicación de ocho casos / Mixed apocrine tumors of the skin: report of 8 cases

Los tumores mixtos de la piel son neoplasias benignas constituídas por elementos epiteliales y mesenquimáticos que conforman estructuras túbulo-alveolares y ductales inmersas en un estroma mixoide o concroide. Se presentan 8 casos de tumores mixtos con diferenciación apocrina localizados en región de la cabeza cuyos diagnósticos clínicos fueron: quiste sebáceo, quiste dermoide, lipoma y mucocele. Histológicamente todos presentaron un patrón epitelial constituído por estructuras tubulares, ductales, túbulo-alveolares o áreas sólidas con diferenciación pilosebácea focal y áreas de metaplasia adiposa. Este último es un rasgo pocas veces referido en la literatura mundial. Los resultadsos de la inmunohistoquímica y los hallazgos morfológicos sugieren un origen común en la unidad folículo sebáceo-apocrina, existiendo una estrecha relación entre los componentes estromales y epiteliales que favorece la diferenciación hacia el aparato sudoríparo