Case report: Efficacy of immunotherapy as conversion therapy in dMMR/MSI-H colorectal cancer: a case series and review of the literature.

Immunotherapy has demonstrated a role in the therapeutic landscape of a small subset of patients with colorectal carcinoma (CRC) that harbor a microsatellite instability (MSI-H) status due to a deficient DNA mismatch repair (dMMR) system. The remarkable responses to immune checkpoint inhibitors (ICIs) are now being tested in the neoadjuvant setting in localized CRC, where the dMMR/MSI-H status can be found in up to 15% of patients, with remarkable results obtained in NICHE2 and 3 trials, among others. This case series aims to report our experience at a tertiary center and provide a comprehensive analysis of the possible questions and challenges to overcome if ICIs were established as standard of care in a neoadjuvant setting, as well as the potential role they may have as conversion therapy not only in locoregional advanced CRC but also in oligometastatic disease.

Localized Colonic Small-Cell Carcinoma with Pathological Complete Response after Neoadjuvant Cisplatin and Etoposide: A Case Report.

Extrapulmonary small-cell carcinoma (SCC) is a rare neoplasm that shares certain features with its pulmonary counterpart and occurs predominantly in the gastrointestinal tract (GIT). It is a high-grade and poorly differentiated neuroendocrine tumor, usually diagnosed in advanced stages, with a poor prognosis and few therapeutic options in that setting. This is a case report of a 77-year-old Spanish male patient with localized SCC of the colon, who presented a pathological complete response in the surgical specimen after neoadjuvant chemotherapy with cisplatin and etoposide. To date, 5 years after surgery, the patient remains without evidence of tumor recurrence. As clinical guidelines for the management of this entity are lacking, and therefore its management has not been standardized, an attempt to summarize the current evidence in the literature was made.

Hemorragia digestiva en paciente con hiperplasia de glándulas de Brunner / Digestive tract hemorrhaging in a patient with Brunner's gland hyperplasia

Resumen Objetivo: analizar las características epidemiológicas, bases etiopatogénicas y presentación clínica, así como el diagnóstico y el tratamiento de la hiperplasia de glándulas de Brunner (HGB). Métodos: describir un caso de HGB diagnosticado de forma incidental durante una endoscopia electiva y realizar una revisión de la literatura disponible hasta el momento. Resultados: esta neoformación consiste en una proliferación glandular localizada preferentemente en el duodeno proximal. Su diagnóstico, normalmente realizado mediante biopsia endoscópica, puede asociarse con complicaciones que, aunque infrecuentes, no deben ser subestimadas. Conclusiones: las neoplasias duodenales representan un porcentaje pequeño dentro del total de las que afectan al tracto gastrointestinal. Debido a que el diagnóstico de estas lesiones suele realizarse de forma casual durante una endoscopia programada, el tratamiento deberá basarse en la sintomatología, así como el tamaño de las mismas, de acuerdo con los estándares de tratamiento de cada centro.

Abstract Objective: This study analyzes the epidemiological characteristics, etiological and pathogenic bases, clinical presentation, diagnosis and treatment of Brunner's gland hyperplasia. Methods: We describe a case of Brunner's gland hyperplasia that was diagnosed incidentally during elective endoscopy and review the available literature. Results: This neoplasm consists of glandular proliferation preferentially located in the proximal duodenum. Its diagnosis, normally made by endoscopic biopsy, can be associated with complications that, although infrequent, should not be underestimated. Conclusions: Duodenal neoplasms are a small percentage of those that affect the gastrointestinal tract. Because diagnosis is usually made by chance during a scheduled endoscopy, treatment should be based on the symptoms and size of the lesion according to the treatment standards of each medical center.

Cutaneous epithelioid hemangioendothelioma on the sole of a child.

Epithelioid hemangioendothelioma (EHE) has been considered to be a low-grade malignant vascular neoplasm, although follow-up of recent series has demonstrated that EHE involving the skin and soft tissues should be better regarded as a fully malignant vascular tumor since it has more metastatic potential than previously thought. We report a case of an EHE involving the left sole of 6-year-old boy, the youngest patient with cutaneous EHE described to date. Immunohistochemical studies demonstrated a lymphatic endothelial line of differentiation for neoplastic cells. Cutaneous EHE is rare in childhood, with only five previously described cases.