RESUMEN
Resumen Una de las características inusuales del melanoma cutáneo es la capacidad de metastatizar en el intestino delgado. A menudo se diagnostica durante la autopsia, en la cual se ha encontrado depósitos metastásicos en el 50%-60% de los casos, pero menos del 2% al 4% de los pacientes con diagnóstico de melanoma tiene metástasis gastrointestinal (GI) durante el curso de la enfermedad y entre el 4%-9% de casos de melanoma GI tiene un primario desconocido. La rápida identificación y resección del melanoma en el tracto digestivo podría mejorar la tasa de supervivencia en aquellos pacientes en los que se presentan complicaciones, como obstrucción intestinal. Se presenta un caso clínico de melanoma gastrointestinal de origen primario desconocido. El porcentaje de este tipo de casos es poco frecuente. La paciente presentó cuadro clínico de náuseas, hiporexia, epigastralgia, fatiga, parestesias en región dorsal derecha y disminución de 9 kilogramos en 3 semanas. Le realizaron tomografía computarizada (TAC) de abdomen contrastado, que reportó 3 lesiones en hígado de predominio isodenso en el parénquima, con algunas áreas de menor densidad al interior, localizadas en los segmentos 2, 5, 7 y 8 del hígado al que se le realizó la biopsia. Se llevó a cabo endoscopia de vías digestivas altas con biopsia de 2 lesiones hiperpigmentadas en la segunda porción de duodeno. El examen histopatológico de las biopsias evidenció melanoma maligno. Se excluyeron todas las localizaciones típicas de melanoma primario durante el procedimiento diagnóstico.
Abstract One of the unusual characteristics of cutaneous melanoma is its ability to metastasize in the small intestine. It is often diagnosed during autopsies of cutaneous melanoma patients. Metastatic deposits have been found in 50% to 60% of these autopsies, but less than 2% to 4% of patients diagnosed with melanoma have gastrointestinal metastasis during the course of the disease. Between 4% and 9% of gastrointestinal melanoma cases have unknown primary tumors. Rapid identification and resection of melanoma in the digestive tract could improve the patient survival rate and prevent complications such as intestinal obstructions from occurring. We present a rare clinical case of gastrointestinal melanoma of unknown primary origin. The patient had a clinical picture of nausea, hyporexia, epigastralgia, fatigue, paresthesias in the right dorsal region and had lost nine kilograms in three weeks. An abdominal CT scan showed three predominantly isodense liver lesions in the parenchyma, with some areas of lower density located in segments 2,5,7 and 8 of the liver. These were biopsied. Upper digestive tract endoscopy took biopsy samples of two hyperpigmented lesions in the second portion of the duodenum. Histopathological examination showed malignant melanoma. All typical locations of primary melanoma were excluded during the diagnostic procedure.
Asunto(s)
Humanos , Femenino , Persona de Mediana Edad , Neoplasias Primarias Desconocidas , Tracto Gastrointestinal , Melanoma , Metástasis de la NeoplasiaRESUMEN
Gene frequencies of RBC antigens were determined in Holsteins and Colombian (criollas) cattle living at 3,000 m, and in cattle descended from fighting bulls (Vacas de lidia) living at 2,500 m. These frequencies were compared with those of Holsteins, cattle native to Florida (scrub cattle), longhorns, and native cattle from Brazil (caracu cattle) living at sea level. The criollas, Vacas de lidia, scrub cows, longhorns, and caracu are descendants of original Iberian stock introduced to the Americas. We found that despite common ancestry (scrub cattle, long-horns, criollas, and caracu), genetic differences may have been derived through years of demographic isolation. The most remarkable blood-group differences were found in the high prevalence of the B system phenogroup (heritable group of antigenic factors) BQA'G'34 in the Vacas de lidia, and of the S system phenogroup U1H' in these cattle and in caracu. Furthermore, the gene frequencies differed in the Holsteins maintained at moderately high altitude (descended from Holsteins kept at sea level), and may have been reflective of the need to adapt to moderately high altitude and chronic hypoxemic conditions. Blood group polymorphism was found in all groups of cattle, although it was reduced in the Vacas de lidia, possibly because their breeding has been carefully controlled and they appear to be highly inbred.