Disponibilidad de técnicas moleculares para niños con tumores de difícil caracterización. Un problema en la Oncopatología pediátrica. Aplicación y difusión de técnicas de diagnóstico complementarias en el ámbito público / Availability of molecular techniques for children with difficult-to-characterize tumors. A problem in pediatric oncopathology. Application and diffusion of complementary diagnostic techniques in the public setting

La revolución de la biología molecular y el desarrollo de la investigación biomédica básica para el diagnóstico y posterior manejo del cáncer infantil han llevado a la necesidad de organización de grupos interdisciplinarios de profesionales, los cuales se encargan de afrontar los nuevos desafíos diagnósticos y terapéuticos. Los sarcomas indiferenciados pediátricos constituyen un grupo heterogéneo de neoplasias malignas de aspecto primitivo y polifenotípico. La categorización de gran parte de este tipo de tumores es posible gracias a la aplicación de técnicas moleculares complementarias al estudio histopatológico. El objetivo del presente estudio fue recategorizar sarcomas indiferenciados mediante la implementación de una nueva metodología diagnóstica. Se efectuaron técnicas de inmunohistoquimica (IHQ), FISH de interfase y RT-PCR a partir de tejido fijado en formol e incluido en parafina en 144 casos de sarcomas indiferenciados. Se logró la recategorización del 95.1% de los casos, arribando a 24 diagnósticos diferentes. Sólo un 4.9% permanece aún como sarcoma indiferenciado o inclasificable. Los resultados alcanzados por este estudio demuestran la importancia de contar con nuevas herramientas diagnósticas a nivel molecular y recursos humanos especializados que posibiliten su correcta implementación para el diagnóstico de neoplasias de difícil caracterización (AU)

The revolution of molecular biology and the development of basic medical research for the diagnosis and subsequent management of childhood cancer have led to a need to organize interdisciplinary groups of professionals in charge of facing new diagnostic and treatment challenges. Childhood undifferentiated sarcomas are a heterogeneous group of malignant neoplasms that are primitive in appearance and have polyphenotypic features. Categorization of a large part of this type of tumor has become possible with molecular techniques as a complement to histopathological studies. The aim of this study was to categorize undifferentiated sarcomas using new diagnostic tools. Immunohistochemistry (IHC), interfase FISH, and RT-PCR techniques were used on formalin-fixed and paraffin-embedded tissues of 144 cases of undifferentiated sarcomas. Overall, 95.1% of the cases could be recategorized resulting in 24 different diagnoses. In only 4.9% the diagnosis of undifferentiated or unclassifiable sarcoma was maintained. These results emphasize the importance of the availability of new diagnostic tools at the molecular level and specialized human resources enabling adequate implementation for the diagnosis of difficult-to-characterize neoplasms (AU)

Micosis fungoide. Experiencia en un hospital pediátrico / Mycosis Fungoides: Experience in a Pediatric Hospital

La micosis fungoide (MF) es el linfoma cutáneo primario de células T más frecuente. Su aparición en la infancia es excepcional. Objetivos: Describir las características epidemiológicas, clínicas, histopatológicas e inmunofenotípicas de los pacientes con MF. Describir los tratamientos utilizados y la evolución. Material y método: Se incluyeron todos los pacientes admitidos en el Hospital de Pediatría Dr. J. P. Garrahan (Argentina) en el período comprendido entre agosto de 1988 y julio de 2014 con diagnóstico clínico e histopatológico de MF. Resultados: Se diagnosticaron 14 pacientes con MF. La distribución por sexo fue M/F: 1:1,33. La edad media al diagnóstico fue de 11,23 años (rango: 8 a 15 años). El tiempo promedio de evolución hasta el momento del diagnóstico fue de 3 años y 6 meses (rango: 4 meses a 7 años). Todos los pacientes presentaron la forma clínica hipopigmentada y en el 42% se asoció la forma clásica. El 50% (n = 7) exhibió un inmunofenotipo CD8 positivo de forma exclusiva. El 78% presentó estadio IB. La fototerapia fue el tratamiento de elección. Cuatro pacientes tuvieron por lo menos una recaída y 3 demostraron progresión de su enfermedad a nivel cutáneo. La evolución fue favorable en todos los casos. Conclusiones: La MF es una entidad infrecuente en la infancia, siendo la forma hipopigmentada la más frecuente. Su diagnóstico es tardío debido a la similitud con otras enfermedades hipopigmentadas frecuentes en la niñez. A pesar de tener un buen pronóstico, presenta alta tasa de recidivas y requiere un seguimiento a largo plazo (AU)

Mycosis fungoides (MF), the most common primary cutaneous T-cell lymphoma, is unusual in children. Objectives: We aimed to describe the epidemiologic, clinical, histopathologic, and immunophenotypic characteristics of MF as well as treatments and course of disease in a pediatric case series. Material and method: Data for all patients admitted to our pediatric hospital (Hospital Dr. J. P. Garrahan) in Argentina with a clinical and histopathologic diagnosis of MF between August 1988 and July 2014 were included. Results: A total of 14 patients were diagnosed with MF. The ratio of boys to girls was 1:1.33. The mean age at diagnosis was 11.23 years (range, 8-15 years). The mean time between onset and diagnosis was 3.5 years (range, 4 months-7 years). All patients had hypopigmented MF and 42% also presented the features of classic MF. Seven (50%) had the CD8+ immunophenotype exclusively. Seventy-eight percent were in stage IB at presentation. Phototherapy was the treatment of choice. Four patients relapsed at least once and skin lesions progressed in 3 patients. All patients improved. Conclusions: MF is unusual in children. The hypopigmented form is the most common. Diagnosis is delayed because the condition is similar to other hypopigmented diseases seen more often in childhood. Although prognosis is good, the rate of recurrence is high, so long-term follow-up is necessary (AU)

Mycosis Fungoides: Experience in a Pediatric Hospital. / Micosis fungoide. Experiencia en un hospital pediátrico.

Mycosis fungoides (MF), the most common primary cutaneous T-cell lymphoma, is unusual in children. OBJECTIVES: We aimed to describe the epidemiologic, clinical, histopathologic, and immunophenotypic characteristics of MF as well as treatments and course of disease in a pediatric case series. MATERIAL AND METHOD: Data for all patients admitted to our pediatric hospital (Hospital Dr. J. P. Garrahan) in Argentina with a clinical and histopathologic diagnosis of MF between August 1988 and July 2014 were included. RESULTS: A total of 14 patients were diagnosed with MF. The ratio of boys to girls was 1:1.33. The mean age at diagnosis was 11.23 years (range, 8-15 years). The mean time between onset and diagnosis was 3.5 years (range, 4 months-7 years). All patients had hypopigmented MF and 42% also presented the features of classic MF. Seven (50%) had the CD8+ immunophenotype exclusively. Seventy-eight percent were in stage IB at presentation. Phototherapy was the treatment of choice. Four patients relapsed at least once and skin lesions progressed in 3 patients. All patients improved. CONCLUSIONS: MF is unusual in children. The hypopigmented form is the most common. Diagnosis is delayed because the condition is similar to other hypopigmented diseases seen more often in childhood. Although prognosis is good, the rate of recurrence is high, so long-term follow-up is necessary.