An unusual manifestation of Langerhans cell histiocytosis in the gastrointestinal tract.

Langerhans cell histiocytosis (LCH) is a monoclonal proliferative disease that can affect multiple organs. It is a rare disorder, and children are the most commonly affected. Its classification depends on whether the disease is localized (usually bone or skin) or systemic. We present the case of a 49-year-old woman with a previous diagnosis of LCH in 2018 with only cutaneous involvement, managed with topical corticosteroids. After developing hypertransaminasemia, a PET-CT scan was performed, showing dissemination of the disease with bone, hepatosplenic and gynecological involvement. In addition, hypermetabolic lesions were described in the cecum with ileocecal adenopathies. A colonoscopy was performed showing in the cecum and ascending colon multiple sessile polyps of 5-10mm with central fibrin-coated erosions, from which biopsies were obtained. Histology revealed typical features of LCH with positive staining for CD1A, S100 and Langerin.

Digestive pseuodpolyposis as a form of presentation of digestive metastases of primary gastric leiomyosarcoma.

A 71-year-old male was diagnosed with gastric leiomyosarcoma in 2020 after biopsies of an ulcerated gastric lesion. Despite oncological treatment, he presented bone, liver and lung progression. Fourth line treatment with Pazopanib was started in 2022 with no evidence of intestinal or peritoneal metastases. He was attended in the Emergency Department in February 2023 due to symptoms of gastrointestinal bleeding with clinical and analytical repercussion with hemoglobin 5.8g/dl. Initially he presented hematemesis and subsequently hematochezia. An upper and lower endoscopic study was performed, revealing multiple sessile polypoid lesions with an irregular mucosal pattern of between 5-30 mm distributed throughout all explored sections at the gastric, duodenal and colic mucosal; some of them ulcerated with fibrin deposits on the surface and signs of recent hemostasis. The histological study demonstrated infiltration by spindle-shaped mesenchymal cells with atypical nuclei, a Ki-67 proliferation index >80%, and an immunohistochemical profile consistent with digestive metastases of primary gastric leiomyosarcoma. CT scan was performed confirming tumor progression with pulmonary, digestive, hepatic, bone, muscle and peritoneal dissemination of gastric leiomyosarcoma.