Histiocitosis combinada de tipo Langerhans (Histiocitosis de células de Langerhans y enfermedad de Erdheim-Chester) en varón de 64 años con mutaciones en BRAF y NRAS: a propósito de un caso / Combined histiocytosis of the Langerhans group (Langerhans cell histiocytosis and Erdheim-Chester disease) in a 64-year-old man with BRAF and NRAS mutations: a case report

Paciente varón de 64 años con antecedente de enfermedad de Crohn que en el contexto de un episodio de dolor abdominal agudo es ingresado en el hospital, siendo diagnosticado, tras el estudio histológico de una biopsia cutánea y otra pulmonar, de una histiocitosis combinada encuadrada dentro de las histiocitosis del grupo L (Langerhans). En la biopsia cutánea se evidenció proliferación de células histiocitarias con positividad inmunohistoquímica para Langerina, CD1a, S100, resultando el estudio molecular de la misma positivo para la mutación BRAF p.V600E. En la biopsia pulmonar se evidenció una proliferación de células histiocitarias con positividad inmunohistoquímica para CD68 y para S100 y negatividad para Langerina y CD1a, detectándose en la misma mutaciones en NRAS c.38G>A en el exón 2 (p.G13D).(AU)

We present a case of a 64-year-old male with a history of Crohn's disease who presented with an episode of acute abdominal pain. He was being investigated for a dermatological lesion. A skin and lung biopsy both revealed histiocytosis of the “L” (Langerhans) group. The skin biopsy showed a proliferation of histiocytic cells expressing Langerin, CD1a and S100 and the molecular study was positive for the BRAF p.V600E mutation. In the lung biopsy, a proliferation of histiocytic cells was found, which were positive for CD68 and S100 and negative for Langerin and CD1a; mutations in NRAS c.38G>A in exon 2 (p.G13D) were also detected.(AU)

[Combined histiocytosis of the Langerhans group (Langerhans cell histiocytosis and Erdheim-Chester disease) in a 64-year-old man with BRAF and NRAS mutations: a case report]. / Histiocitosis combinada de tipo Langerhans (Histiocitosis de células de Langerhans y enfermedad de Erdheim-Chester) en varón de 64 años con mutaciones en BRAF y NRAS: a propósito de un caso.

We present a case of a 64-year-old male with a history of Crohn's disease who presented with an episode of acute abdominal pain. He was being investigated for a dermatological lesion. A skin and lung biopsy both revealed histiocytosis of the "L" (Langerhans) group. The skin biopsy showed a proliferation of histiocytic cells expressing Langerin, CD1a and S100 and the molecular study was positive for the BRAF p.V600E mutation. In the lung biopsy, a proliferation of histiocytic cells was found, which were positive for CD68 and S100 and negative for Langerin and CD1a; mutations in NRAS c.38G>A in exon 2 (p.G13D) were also detected.

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)

Synchronous Warthin tumor and papillary oncocytic cystadenoma in the ipsilateral parotid gland: an unreported association.

The occurrence of ipsilateral, synchronous, primary salivary gland tumors of different histological type is rare. In this report, we present the case of a 52-year-old male, established smoker, who showed simultaneously two different benign tumors in the right parotid gland. The patient complained of swelling below the angle of the mandible. Ultrasonography and computed tomography imaging revealed one mass of about 2.8 cm in the right gland. Besides, one small nodule in the left parotid gland was observed. The cytological diagnosis of the right gland was benign tumor, type IVa of the Milan system, consistent with Warthin tumor (WT). The clinical diagnosis was bilateral parotid WT. The histopathological (HP) study of the surgical specimen revealed a WT in combination with a papillary oncocytic cystadenoma (POC) in the right parotid. To our knowledge, this combination of tumors has not been previously reported. In our case, the association of tumors was not detected by imaging or fine-needle aspiration cytology (FNAC). WT and POC are difficult to distinguish by FNAC because their epithelial component is very similar. POC can resemble WT without lymphoid stroma, but the totality of HP features allows the differentiation of both processes. These tumors can be related to a common causal determinant and should not be considered as a result of chance. Both tumors follow favorable courses and are curable by surgical resection.