Extramedullary plasmacytoma with colonic involvement: experience in a tertiary hospital.

A 71-year-old woman diagnosed with type II diabetes mellitus with severe iron deficiency anemia and positive fecal occult blood. Colonoscopy was performed, showing a soft mass in the ascending colon, with biopsies compatible with plasmacytoma and restriction for Kappa light chains. After bone marrow aspiration, associated IgG multiple myeloma was detected, so chemotherapy with VMP (bortezomib, melphalan and prednisone) was started. Colonoscopy six months later showed that the ulcerated lesion had a reduction in tumor size of up to 80%. A 27-year-old male with a history of kidney transplantation and symptoms of chronic diarrhea, colonoscopy was indicated with the finding of a large exophytic and ulcerated lesion in the cecum. Pathology revealed plasmacytoma with restriction of lambda light chains. After ruling out lesions in other locations, the patient was treated with immunochemotherapy according to the Bortezomib-Rituximab-Dexamethasone scheme, with subsequent complete clinical and endoscopic remission. Plasmacytoma accounts for < 4 % of plasma cell tumours. It may appear isolated or associated with another plasma cell neoplasm, mainly multiple myeloma. Its presence in the gastrointestinal tract is rare, being infrequent in the stomach or small intestine, and even rarer in the colonic tract (incidence 1/10,000,000). The clinical manifestations are similar to those of other colon neoplasms, while the treatment or prognosis may differ from those of other neoplasms. In patients with clinical suspicion, it is important to perform an early endoscopic study, especially in patients diagnosed with multiple myeloma.

Efficiency of Machine Learning Algorithms for the Determination of Macrovesicular Steatosis in Frozen Sections Stained with Sudan to Evaluate the Quality of the Graft in Liver Transplantation.

Liver transplantation is the only curative treatment option in patients diagnosed with end-stage liver disease. The low availability of organs demands an accurate selection procedure based on histological analysis, in order to evaluate the allograft. This assessment, traditionally carried out by a pathologist, is not exempt from subjectivity. In this sense, new tools based on machine learning and artificial vision are continuously being developed for the analysis of medical images of different typologies. Accordingly, in this work, we develop a computer vision-based application for the fast and automatic objective quantification of macrovesicular steatosis in histopathological liver section slides stained with Sudan stain. For this purpose, digital microscopy images were used to obtain thousands of feature vectors based on the RGB and CIE L*a*b* pixel values. These vectors, under a supervised process, were labelled as fat vacuole or non-fat vacuole, and a set of classifiers based on different algorithms were trained, accordingly. The results obtained showed an overall high accuracy for all classifiers (>0.99) with a sensitivity between 0.844 and 1, together with a specificity >0.99. In relation to their speed when classifying images, KNN and Naïve Bayes were substantially faster than other classification algorithms. Sudan stain is a convenient technique for evaluating ME in pre-transplant liver biopsies, providing reliable contrast and facilitating fast and accurate quantification through the machine learning algorithms tested.

[Primary pulmonary myxoid sarcoma associated with translocation EWSR1-CREB1 and locorregional micrometastases]. / Sarcoma pulmonar mixoide primario asociado a traslocación EWSR1-CREB1 con micrometástasis locorregional.

Primary myxoid pulmonary sarcoma is a rare entity with an endobronchial growth. Although it should be included in the differential diagnosis of other sarcomas, its prognosis is usually favorable. We present the case of a 51-year-old patient with a mesenchymal tumor in the right lung, diagnosed as a primary pulmonary myxoid sarcoma, positive for EMA, vimentine and with a Ki-67 less than 5%; FISH revealed a EWSR1-CREB1 translocation.