Primary Ewing's sarcoma/primitive neuroectodermal tumor of the kidney. An infrequent finding.

OBJECTIVE: Ewing's sarcoma/Primitive neuroectodermal tumor (ES/PNET) is an extraordinarily rare primary tumor in the kidney. We re-port herein the clinical, histological, and immunohisto-chemical features of a primary renal ES/PNET. METHODS: A 19-year old male referred a two weeks history of constant, colic, left flank pain, and fever. A left radical nephrectomy was performed. Gross pathologic examination showed pink-tan, lobulated solid tumor, localized at the superior pole. RESULTS: Histologically, the tumor was solid with necrosis. The neoplastic cells showed a small amount of clear cytoplasm, and had vesicular nuclei with small nucleoli. Immunohistochemical studies showed strongly and diffusely positive staining for CD99 in a membranous pattern. CONCLUSIONS: This case represents a typical ES/ PNET affecting a young male patient. Adequate diagnosis is important because this neoplasm has an aggressive behaviour.

Extragonadal retroperitoneal germ cell tumor: primary versus metastases?

OBJECTIVE: Primary extragonadal germ cell tumors are rare and their histogenetic origin is not clear. We describe two cases presenting as primary retroperitoneal germ cell tumors without clinical evidence of testicular tumor. METHODS: A 21 and 18 years-old patients presented retroperitoneal choriocarcinoma and yolk sac tumor, respectively. In both cases, testicular palpation was not suspicious for testicular cancer. Testicular ultrasound founded alterations in right testes. RESULTS: A right orchitectomy were performed and the final diagnostics were mature teratoma associated with intratubular malignant germ cell. CONCLUSION: Adult mature teratoma is infrequent and the retroperitoneal germ cell tumors should be considered to be metastases of a viable or burned-out testicular cancer.

Extragonadal retroperitoneal germ cell tumor: primary versus metastases? / Tumor de células germinales extragonadal retroperitoneal: ¿Tumor primario o metastásico?

Objetive: Primary extragonadal germ cell tumors are rare and their histogenetic origin is not clear. We describe two cases presenting as primary retroperitoneal germ cell tumors without clinical evidence of testicular tumor. Methods: A 21 and 18 years-old patients presented retroperitoneal choriocarcinoma and yolk sac tumor, respectively. In both cases, testicular palpation was not suspicious for testicular cancer. Testicular ultrasound founded alterations in right testes. Results: A right orchitectomy were performed and the final diagnostics were mature teraroma associated with intratubular malignant germ cell. Conclusions: Adult mature teratoma is infrequent and the retroperitoneal germ cell tumors should be considered to be metastases of a viable or burned–out testicular cancer (AU)

Objetivo: Los tumores primarios de células germinales extragonadales son poco frecuentes y su origen histogenético no está claro. Describimos dos casos que se presentaron como tumores de células germinales retroperitoneales sin evidencia clínica de tumor testicular. Métodos: Dos pacientes de 21 y 18 años presentaron respectivamente un coriocarcinoma y un tumor del saco embrionario retroperitoneales. En ambos casos, la palpación testicular no era sospechosa de cárcel testicular. La ecografía testicular descubrió alteraciones en los testículos derechos de ambos pacientes. Resultados: Se llevó a cabo orquiectomía derecha con el diagnóstico final de teratoma maduro asociado con células germinales malignas intratubulares. Conclusiones: El teratoma maduro del adulto es poco frecuente, y los tumores de células germinales retroperitoneales deben ser consideradas metástasis de un cáncer testicular fundido (AU)

Primary Ewing´s sarcoma/primitive neuroectodermal tumor of the kidney. An infrequent finding / Sarcoma de Ewing primario/Tumor neuroectodérmico primitivo renal. Un hallazgo infrecuente

Objetive: Ewing's sarcoma/Primitive neuroectodermal tumor (ES/PNET) is an extraordinarily rare primary tumor in the kidney. We report herein the clinical, histological, and immunohisto-chemical features of a primary renal ES/PNET. Methods: A 19-year old male referred a two weeks history of constant, colic, left flank pain, and fever. A left radical nephrectomy was performed. Gross pathologic examination showed pink-tan, lobulated solid tumor, localized at the superior pole. Results: Histologically, the tumor was solid with necrosis. The neoplastic cells showed a small amount of clear cytoplasm, and had vesicular nuclei with small nucleoli. Immunohistochemical studies showed strongly and diffusely positive staining for CD99 in a membranous pattern. Conclusions: This case represents a typical ES/PNET, affecting a young male patient. Adequate diagnosis is important because this neoplasm has an aggressive behaviour (AU)

El sarcoma de Ewing/Tumor Neuroectodermico Primitivo (SE/TNEP) del riñón es una neoplasia extremadamente rara en el riñón. Presentamos los hallazgos clínicos, histológicos e inmunohistoquímicos de un SE/TNEP primario renal. Métodos: Un paciente varón de 19 años refirió historia de dos semanas de dolor tipo cólico, constante, en el flanco izquierdo y fiebre. Se hizo nefrectomía radical izquierda. El examen macroscópico mostró un tumor sólido, lobulado, pardo-rosado, localizado en el polo superior. Resultados: Histológicamente el tumor era sólido con necrosis. Las células neoplásicas mostraron citoplasma escaso claro y poseían un núcleo vesicular con nucléolo pequeño. Los estudios inmunohistoquímicos mostraron una fuerte y difusa positividad para el CD99 en un patrón membranoso. Conclusiones: Este caso representa un típico SE/TNEP, afectando a un varón joven. Es importante un diagnóstico adecuado debido a que esta neoplasia tiene una conducta agresiva (AU)