Biopsia guiada por TC de tumores sacros agresivos. ¿Es siempre diagnóstica? / Is CT-guided biopsy of aggressive sacral tumors always able to reach a diagnosis?

Objetivos. Presentar una serie de 8 casos de tumores sacros infrecuentes, que representan un amplio espectro de la patología agresiva que asienta en este hueso y discutir la eficacia de la técnica de biopsia guiada por TC. Material y métodos. Se revisó retrospectivamente a todos los pacientes con tumoraciones sacras a los que se hizo biopsia guiada por TC en nuestro servicio, durante los últimos 2 años. Antes de realizar la biopsia, se analizaron las imágenes previas de TC y RM para dirigir correctamente la biopsia. Se realizó una TC dirigida a la lesión con cortes de 3mm, para determinar la localización de la zona diana y el trayecto de la aguja. Se utilizó en todos los casos aguja de 11G y aguja coaxial de 15G. Resultados. Se biopsiaron 8 lesiones sacras, de las cuales, en 4 se consiguió el diagnóstico con biopsia guiada con TC. En 3 de ellas solo fue necesaria una sesión, con los diagnósticos de cordoma, plasmocitoma y metástasis de melanoma, mientras que en otro caso se tuvieron que realizar 3 sesiones, llegando al diagnóstico de sarcoma de Ewing. En los otros 4 casos fue necesaria la biopsia quirúrgica por distintos motivos. En ellos los diagnósticos definitivos fueron condrosarcoma, granuloma eosinófilo y en 2 pacientes linfoma óseo primario. La eficacia diagnóstica de la técnica fue del 36%. Conclusión. Nuestros resultados sugieren que la biopsia guiada por TC es menos útil en la caracterización de tumores primarios que en metástasis, siendo especialmente complicado el diagnóstico de linfomas óseos primarios. La repetición del procediendo tras resultados no diagnósticos, probablemente no aporte información adicional, por lo que es recomendable recurrir a biopsia quirúrgica (AU)

Objectives. To present a series of eight cases of rare sacral tumors that represent a wide spectrum of the aggressive disease involving the sacrum and to discuss the efficacy of CT-guided biopsy in these cases. Material and methods. We reviewed all cases of sacral tumors biopsied under CT guidance in the last two years. Prior CT and MR images were analyzed before biopsy, and 3mm CT slices of the lesion were obtained to determine the location of the target area and the path of the needle. All biopsies were performed using 11G needles and 15G coaxial needles. Results. Eight sacral lesions were biopsied under CT guidance, and a diagnosis was reached in four. In three of these, the diagnosis (chordoma, plasmocytoma, and metastasis from melanoma) was reached in a single session. In the fourth case, three sessions were necessary to reach the diagnosis of Ewing's sarcoma. For various reasons, the remaining four cases required surgical biopsy to reach the diagnoses of chondrosarcoma, eosinophilic granuloma, and primary bone lymphoma in two patients. The diagnostic efficacy of CT-guided biopsy was 36%. Conclusion. Our results suggest that CT-guided biopsy is less useful in the characterization of primary tumors than in metastases. The diagnosis of primary bone lymphomas is especially complicated. Repeating the procedure after inconclusive results probably will not provide additional information, and it is recommendable to perform surgical biopsy in these cases (AU)

[Is CT-guided biopsy of aggressive sacral tumors always able to reach a diagnosis?]. / Biopsia guiada por TC de tumores sacros agresivos. ¿Es siempre diagnóstica?

OBJECTIVES: To present a series of eight cases of rare sacral tumors that represent a wide spectrum of the aggressive disease involving the sacrum and to discuss the efficacy of CT-guided biopsy in these cases. MATERIAL AND METHODS: We reviewed all cases of sacral tumors biopsied under CT guidance in the last two years. Prior CT and MR images were analyzed before biopsy, and 3 mm CT slices of the lesion were obtained to determine the location of the target area and the path of the needle. All biopsies were performed using 11 G needles and 15 G coaxial needles. RESULTS: Eight sacral lesions were biopsied under CT guidance, and a diagnosis was reached in four. In three of these, the diagnosis (chordoma, plasmocytoma, and metastasis from melanoma) was reached in a single session. In the fourth case, three sessions were necessary to reach the diagnosis of Ewing's sarcoma. For various reasons, the remaining four cases required surgical biopsy to reach the diagnoses of chondrosarcoma, eosinophilic granuloma, and primary bone lymphoma in two patients. The diagnostic efficacy of CT-guided biopsy was 36%. CONCLUSION: Our results suggest that CT-guided biopsy is less useful in the characterization of primary tumors than in metastases. The diagnosis of primary bone lymphomas is especially complicated. Repeating the procedure after inconclusive results probably will not provide additional information, and it is recommendable to perform surgical biopsy in these cases.