RESUMENSe reporta el caso de un paciente de 67 años que presenta dolor en el glúteo derecho que se irradia hacia los muslos afectando la bipedestación y la marcha. Con tiempo de enfermedad de cuatro meses, asociado con la disminución de 15 kg de peso; se realizaron exámenes de imágenes donde se encontró un proceso infiltrativo de hueso sacro. La biopsia se informó como lesión de tejido óseo infiltrado por adenocarcinoma poco diferenciado. La evaluación urológica clínica, a pesar del valor del antígeno prostático específico (PSA total: 4,62 mg/dL), encontró una lesión nodular menor a un centímetro en el examen de tacto rectal. La biopsia de próstata evidenció un adenocarcinoma pobremente diferenciado (score de Gleason: 8). La gammagrafía ósea mostró lesiones activas relacionadas con metástasis en tercio medio de clavícula derecha, hueso sacro y región púbica derecha. Palabras clave: Cáncer de próstata; Antígeno prostático específico; Metástasis de la neoplasia (fuente: DeCS BIREME). METASTATIC PROSTATE CANCER ASSOCIATED WITH LOW LEVELS OF PROSTATE-SPECIFIC ANTIGEN ABSTRACTA case was reported of a 67-year-old patient with right buttock pain radiating to the thighs and affecting his bipedalism and gait. With four months into the disease and a weight loss of 15 kilos, the patient underwent imaging tests which showed sacrum infiltration. The biopsy diagnosis was injury of bone tissue infiltrated by poorly differentiated adenocarcinoma. The rectal examination performed as part of the clinical urologic examination revealed a nodular lesion of less than one centimeter, despite the level of prostate-specific antigen (total PSA: 4.62 mg/dL). The prostate biopsy evidenced a poorly differentiated adenocarcinoma (Gleason score: 8). The bone scan showed active lesions associated with metastasis in the middle third of the right clavicle, the sacrum and the right pubic region.

A case was reported of a 67-year-old patient with right buttock pain radiating to the thighs and affecting his bipedalism and gait. With four months into the disease and a weight loss of 15 kilos, the patient underwent imaging tests which showed sacrum infiltration. The biopsy diagnosis was injury of bone tissue infiltrated by poorly differentiated adenocarcinoma. The rectal examination performed as part of the clinical urologic examination revealed a nodular lesion of less than one centimeter, despite the level of prostate-specific antigen (total PSA: 4.62 mg/dL). The prostate biopsy evidenced a poorly differentiated adenocarcinoma (Gleason score: 8). The bone scan showed active lesions associated with metastasis in the middle third of the right clavicle, the sacrum and the right pubic region.