Intestinal infantile fibrosarcoma with translocation of NTRK. A case report and review of the literature / Fibrosarcoma intestinal infantil con translocación de NTRK y revisión de casos de la literatura

Introduction: Infantile fibrosarcoma is a rare non-rhabdomyosarcomatous soft tissue tumor (0.0005%) of which only 10% occur in the abdomen where they rarely affect the gastrointestinal tract. The median age at diagnosis is 3 months although 40% of them are present at birth. Material and methods: When infantile fibrosarcoma is diagnosed in our center, a clinical–pathological description is made together with a bibliographic review. Results: We present the case of a 6-day-old girl who presented with irritability and rejection of food. She was diagnosed with acute abdomen due to perforation and underwent surgery where a mass on the ascending colon was removed. Histopathology revealed a proliferation of spindle cells consisting of intertwined fascicles, infiltrating the adjacent tissues. Nuclear pleomorphism, few mitoses, foci of necrosis and hemorrhage are seen. Immunohistochemistry showed positivity for Pan-TRK and the NGS panel (Archer DX) demonstrated the TPR::NTRK1 fusion. No case with these characteristics, location or TPR::NTRK1 fusion were found in the literature. Conclusions: Infantile fibrosarcoma is a very infrequent tumor which is exceptionally rare in the intestine. It is important to look for the characteristic genetic rearrangement of these tumors both to confirm the diagnosis and differentiate them from other pediatric spindle cell tumors and determine the correct targeted treatment. Selective TRK inhibitors have shown a 75% response rate in children and adults with tumors that exhibit TRK fusion. It was possible to find fusions with the Archer DX panel that the Oncomine panel did not detect.(AU)

Introducción: El fibrosarcoma infantil es un tumor infrecuente del tejido blando no rabdomiosarcomatoso (0,0005%). Solo el 10% se produce en el abdomen y pocos de ellos afectan al tracto gastrointestinal. La edad media de su diagnóstico es de 3 meses, presentándose el 40% de ellos al nacer. Material y métodos: Con motivo del diagnóstico de un caso de fibrosarcoma infantil en nuestro centro realizamos una descripción clínico-patológica del mismo, y llevamos a cabo una revisión de la literatura al respecto. Resultados: Presentamos el caso de una niña de 6 días de edad, que inició con irritabilidad y rechazo de alimentos, a quien se diagnosticó abdomen agudo debido a perforación. En la intervención quirúrgica se extirpó una masa dependiente en el colon ascendente. El estudio histológico mostró una proliferación de células fusiformes compuesta de fascículos entrelazados, con infiltración en los tejidos adyacentes. Se identificaron pleomorfismo nuclear, pocas mitosis, focos de necrosis y hemorragia. Se obtuvo positividad inmunohistoquímica para Pan-TRK, demostrando el panel de NGS (Archer DX) la fusión TPR::NTRK1. No encontramos en la literatura ningún caso con estas características, localización intestinal y fusión TPR::NTRK1. Conclusiones: El fibrosarcoma infantil es un tumor muy raro, siendo excepcional la localización intestinal. Es importante la búsqueda de la reorganización genética característica de estos tumores, tanto para esclarecer el diagnóstico como para diferenciarlos de otros tumores de células fusiformes de aparición en niños, así como para aportar un tratamiento focalizado. Los inhibidores selectivos de TRK han reflejado una tasa de respuesta del 75% en niños y adultos con tumores que exhiben fusión de TRK. Fue posible encontrar fusiones utilizando el panel Archer DX, no detectadas por el panel Oncomine.(AU)

Is Routine Prophylaxis Against Pneumocystis jirovecii Needed in Liver Transplantation? A Retrospective Single-Centre Experience and Current Prophylaxis Strategies in Spain.

In liver transplant (LT) recipients, Pneumocystis jirovecii pneumonia (PJP) is most frequently reported before 1992 when immunosuppressive regimens were more intense. It is uncertain whether universal PJP prophylaxis is still applicable in the contemporary LT setting. We aimed to examine the incidence of PJP in LT recipients followed at our institution where routine prophylaxis has never been practiced and to define the prophylaxis strategies currently employed among LT units in Spain. All LT performed from 1990 to October 2019 were retrospectively reviewed and Spanish LT units were queried via email to specify their current prophylaxis strategy. During the study period, 662 LT procedures were carried out on 610 patients. Five cases of PJP were identified, with only one occurring within the first 6 months. The cumulative incidence and incidence rate were 0.82% and 0.99 cases per 1000 person transplant years. All LT units responded, the majority of which provide prophylaxis (80%). Duration of prophylaxis, however, varied significantly. The low incidence of PJP in our unprophylaxed cohort, with most cases occurring beyond the usual recommended period of prophylaxis, questions a one-size-fits-all approach to PJP prophylaxis. A significant heterogeneity in prophylaxis strategies exists among Spanish LT centres.

Popliteal Angiosarcoma after Bypass with Autologous Saphenous Vein.

Angiosarcoma (AS) is a type of malignancy within sarcomas affecting soft tissue and bone. It presents a very heterogeneous distribution in the human body, and it can appear in multiple locations, from breast to liver or skin. The incidence of this type of tumor is low; however, it is aggressive and requires an early diagnosis to initiate the treatment as soon as possible. In the present article, we report the case of a male patient who was diagnosed with epithelioid AS of popliteal artery after an aneurysm popliteal surgery, as well as its treatment and evolution. This kind of tumors has controversial treatment and poor survival rates in the early years.