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Objective Definitive staging for cervical (CC) and endometrial cancer (EC) takes place once surgery is performed. The aim of this study was to evaluate the role of PET/CT in detecting lymphatic metastasis in patients with CC and EC using dual-time-point imaging (DPI), taking the histopathological results of sentinel lymph node (SLN) and lymphadenectomy as the reference. Material and methods A prospective study was conducted on 17 patients with early CC, and 13 patients with high-risk EC. The patients had a pre-operative PET/CT, MRI, SLN detection, and lymphadenectomy, when indicated. PET/CT findings were compared with histopathological results. Results In the pathology study, 4 patients with CC and 4 patients with EC had lymphatic metastasis. PET/CT showed hypermetabolic nodes in 1 patient with CC, and 5 with EC. Four of these had metastasis, one detected in the SLN biopsy. Four patients who had negative PET/CT had micrometastasis in the SLN biopsy, 1 patient with additional lymph nodes involvement. The overall patient-based sensitivity, specificity, positive and negative predictive values, and accuracy of PET/CT to detect lymphatic metastasis was 20.0%, 100.0%, 100.0%, 87.9%, and 88.2%, respectively, in CC, and 57.1%, 88.9%, 66.7%, 84.2% and 80.0%, respectively, in EC. DPI showed higher retention index in malignant than in inflammatory nodes, although no statistically significant differences were found. Conclusions PET/CT has low sensitivity in lymph node staging of CC and EC, owing to the lack of detection of micrometastasis. Thus, PET/CT cannot replace SLN biopsy. Although no statistically significant differences were found, DPI may help to differentiate between inflammatory and malignant nodes.

Molecular imaging with 123I-metaiodobenzylguanidine (MIBG) has been used in Parkinson’s disease (PD), but there is no consensual index to discriminate between normal and PD patients in the Caucasian population. The purpose of this study was to determine diagnostic cutoff points in the quantification of MIBG cardiac uptake in our population of PD patients. We have also calculated the reproducibility over a range of interpretation expertise. The study included 14 PD patients and 14 normal age- and sex-matched controls. Heart to mediastinum ratios (H/M) were calculated at 15 min (H/M15m) and 4 h (H/M4h) post-injection by three observers with different interpretation expertise, one of whom drew the regions of interest at three different times. The intraobserver and interobserver reliability was calculated (interclass correlation coefficient and coefficient of variability). Diagnosis was estimated by maximizing the Youden index for H/M and washout ratios. Discrimination ability was assessed by the area under the curve (AUC). Sensitivity and specificity were reported, using our thresholds. The parameter with the best diagnostic accuracy was the H/M4h ratio, with a major AUC (0.976 area under the receiver-operating characteristic curve). The threshold was 1.43 with a 95% confidence interval of 1.37–1.50. Using this threshold, the sensitivity and specificity were 93 and 100%. The interobserver and intraobserver variabilities measuring this ratio were 3.2 and 3.1%, respectively. The diagnostic cutoff point for 123I-MIBG myocardial scintigraphy in a Caucasian population with PD was 1.43 for the H/M4h index, with a good sensitivity and specificity. The technique is easy to use, with a good reproducibility over a range of interpretation expertise.

OBJECTIVE To evaluate the effect of calcimimetics with 99mTc-methoxy-isobutyl-isonitrile (MIBI) parathyroid scintigraphy in secondary hyperparathyroidism. METHODS This prospective study included 30 consecutive haemodialysis patients with inadequately controlled secondary hyperparathyroidism despite standard medical treatment. Patients were given a single daily oral dose of 30 mg of cinacalcet. A baseline and 1-year follow-up dual-phase 99mTc-MIBI scintigraphy were performed. 99mTc-MIBI uptake in each parathyroid gland was graded on a semiquantitative scale (scoring 0-3). RESULTS Twenty-one of the 30 patients responded to cinacalcet (70%). Abnormal positive glands were identified by 99mTc-MIBI scintigraphy in 27 out of 30 patients (53 glands). The sensitivity and specificity of 99mTc-MIBI in detecting cinacalcet response were 90 and 89%, respectively. The mean baseline and posttreatment grades of 99mTc-MIBI uptake were 2.9 ± 1.8 and 1.1 ± 1.2 (P < 0.0001) in the responder group and 3.1 ± 2.1 and 3.9 ± 2.2 (P = ns) in the nonresponder group. CONCLUSION 99mTc-MIBI scintigraphy is useful in monitoring the response to calcimimetics in secondary hyperparathyroidism.

Resumen Aunque la identificacion del ganglio centinela (GC) presenta en la actualidad una amplia aplicacion en el melanoma y el cancer de mama, no se utiliza rutinariamente en otras neoplasias, como pueden ser las ginecologicas. Objetivo Evaluar la aplicabilidad y los resultados de la tecnica de localizacion del GC en pacientes con canceres ginecologicos. Metodo Se estudiaron 155 pacientes con diversas neoplasias ginecologicas (70 vulvares, 50 de cuello uterino y 35 endometriales). Se realizo una linfogammagrafia el dia previo a la intervencion quirurgica mediante la inyeccion de 111 MBq de 99mTc-nanocoloide por diversas vias segun el tipo de lesion. La localizacion intraoperatoria se realizo mediante una sonda detectora y en 100 casos (70 vulvares y 30 de cuello uterino) se administro tambien un colorante vital pocos minutos antes del inicio de la intervencion. Se realizo estudio anatomopatologico del GC. Se practico linfadenectomia reglada en todas las pacientes con cancer de cervix y de endometrio y en las primeras 35 pacientes con cancer de vulva. Resultados La linfogammagrafia prequirurgica visualizo como minimo un GC en el 97% de los canceres de vulva, en el 92% de cervix y el 64% de tumores de endometrio. Intraoperatoriamente la localizacion del GC mostro unos porcentajes del 97, del 90 y del 62%, respectivamente. El estudio anatomopatologico demostro metastasis en el 24,2% de las pacientes con lesiones vulvares, el 8,8% en las de cervix y el 4,5% en las de endometrio. El porcentaje de falsos negativos fue del 5,5% en los canceres de vulva (1 caso), presentandose 2 casos en el endometrio y ninguno en las pacientes con cancer de cervix. Conclusion La linfogammagrafia es una tecnica util y sencilla para identificar los GC en este tipo de tumores. La biopsia del GC ofrece resultados fiables en los canceres de vulva y cuello uterino. Sin embargo, en el cancer de endometrio nuestros resultados no son optimos y debe valorarse la adecuacion de la tecnica.

Objetivo. Analizar la utilidad de la gammagrafia de medula macrofagica en el diagnostico diferencial de infeccion de protesis total de cadera dolorosa valorada con gammagrafia con leucocitos marcados. Material y metodos. Se han estudiado prospectivamente 70 pacientes (42 mujeres, 28 hombres) con una edad de 68 ± 13 anos con protesis total de cadera y dolor local. Se determino la velocidad de sedimentacion globular (VSG) y proteina C reactiva (PCR) y se realizo gammagrafia osea con leucocitos marcados con 99mTc-HMPAO y de medula macrofagica con 99mTc-sulfuro coloidal a todos los pacientes. El diagnostico definitivo se realizo mediante estudio microbiologico o seguimiento clinico minimo de 12 meses. Resultados. Se diagnostico infeccion en 12 de los 70 casos (3 estafilococo coagulasa negativo, 2 Staphylococcus aureus, 2 Staphylococcus epidermidis, 2 Enterococcus y 3 polimicrobianas). La VSG y la PCR en el grupo de pacientes con infeccion resulto significativamente mayor que en el grupo de no infectados (51,8 ± 29,4 frente a 25,4 ± 16,4 y 2,8 ± 2,2 frente a 1,1 ± 1,3 respectivamente; p < 0,05). La gammagrafia osea no mostro un patron de captacion que permitiese diferenciar entre infeccion y aflojamiento aseptico. La fase vascular de la gammagrafia osea fue positiva en 3 de 12 pacientes infectados. La gammagrafia con leucocitos marcados aislada mostro una sensibilidad y especificidad de 83 y 57 %, respectivamente. La gammagrafia de medula macrofagica incremento estos resultados a cifras de 92 y 98 %, respectivamente. Conclusiones. La practica adicional de una gammagrafia de medula macrofagica mejora significativamente los resultados de la gammagrafia con leucocitos marcados en el diagnostico de infeccion de protesis total de cadera. La gammagrafia osea no permite diferenciar entre aflojamiento aseptico e infeccion protesica en esta serie de pacientes.

Resumen El ganglio centinela (GC) es el primer ganglio linfatico de un determinado lecho ganglionar que recibe directamente drenaje linfatico del tumor primario. Sin embargo, en algunos pacientes existen nodulos linfaticos que se situan entre el tumor primario y la primera estacion ganglionar regional. Se trata de “ganglios en transito” y deben ser considerados GC. Objetivo Fue determinar el porcentaje y la localizacion de los GC en transito obtenidos de una muestra de pacientes con melanoma maligno y valorar la necesidad de resecar este tipo de ganglios. Metodo Se incluyeron en el estudio un total de 900 pacientes con melanoma maligno. El dia previo a la cirugia se realizo la linfogammagrafia mediante la administracion de 4 inyecciones intradermicas de 74-111 MBq de 99mTc-Nanocoloide alrededor de la lesion primaria o en la zona de la biopsia escisional. Resultados Las imagenes revelaron la presencia de GC en transito en 80 pacientes (8,9 %). Durante el acto quirurgico se consiguieron extirpar los GC en transito en 77 de los 80 pacientes (96,2 %). En el analisis histologico se hallaron metastasis en 15 pacientes (19,5 %) y, de estos, 4 no presentaron afectacion tumoral del lecho linfatico regional. Conclusiones La linfogammagrafia es imprescindible en la localizacion de los GC en transito. Asimismo, aunque el porcentaje de GC en transito en pacientes afectos de melanoma maligno es relativamente bajo, la afectacion tumoral de los mismos alcanza un porcentaje significativo. Por ello, creemos que la reseccion de los GC en transito es necesaria en todos los casos.

Summary Aim To evaluate the usefulness of 99m Tc-Sulphur colloid when combined with leukocyte scintigraphy in suspected prosthetic hip infection, comparing the results with information from 99m Tc-HMPAO-leukocyte scintigraphy alone. Materials and methods Seventy patients (42 women, 28 men; mean age ± 13 years) with painful hip prostheses and suspicion of infection were evaluated prospectively. All patients had bone scintigraphy, 99m Tc-HMPAO-labelled white blood cell scintigraphy and 99m Tc-Sulphur colloid bone marrow scintigraphy. ESR and CRP levels were measured in all patients. The final diagnosis was made with microbiological findings or by clinical follow up of at least 12 months. Results Infections were diagnosed in 12 of the 70 patients (3 coagulase-negative Staphylococcus , 2 Staphylococcus aureus , 2 Staphylococcus epidermidis , 2 enterococcus and 3 polymicrobial agents). ESR and CRP values were higher in patients with infection than in patients without infection (51.8 ± 29.4 vs. 25.4 ± 16.4 and 2.8 ± 2.2 vs. 1.1 ± 1.3, respectively; p Conclusion Performing bone marrow scintigraphy significantly improves results when compared with leukocyte scintigraphy alone in the diagnosis of infected hip prostheses. Bone scintigraphy did not help to differentiate aseptic loosening from infection in this series.

Summary The sentinel lymph node (SLN) is the first node in a lymph node basin to receive direct drainage from the primary tumour. However, in some cases, lymphoscintigraphy images demonstrate the presence of lymph nodes located in the area between the primary tumour and the first regional lymph node basin. These nodes are called in-transit nodes and have to be considered SLNs as well. Aim It was to determine the incidence and location of in-transit SLNs in patients with malignant melanoma and to evaluate whether it is necessary to harvest them. Method Nine hundred patients with malignant melanoma were included. Lymphoscintigraphy was performed on the day before surgery following intradermal injection of 74-111 MBq of 99mTc-Nanocolloid in four doses around the primary lesion or the biopsy scar. Results The presence of in-transit SLNs was revealed in 80 patients. During surgery, in-transit SLNs were identified and excised in all but 3 patients (96.2%). Metastatic cell deposits were identified in these in-transit SLNs in 15 patients (19.4%), with 4 patients with no tumour involvement of the regional lymph node basin. Conclusions Lymphoscintigraphy is mandatory in the location of in-transit SLNs. Moreover, although the incidence of these nodes is relatively low in malignant melanoma, the presence of metastatic cells in these in-transit SLNs reaches a significant percentage. Therefore, excision of in-transit SLNs is necessary in all cases.

Resumen Objetivo Valorar la validez de la tecnica de biopsia radioguiada del ganglio centinela (GC) en el carcinoma escamoso de pene. Material y metodos Se han estudiado un total de 15 pacientes con carcinoma escamoso de pene. Los 5 primeros pacientes constituyeron un grupo de validacion de la tecnica al cual se le realizo linfadenectomia inguinal reglada, tras los procedimientos descritos a continuacion. Los 10 pacientes restantes constituyeron el grupo de aplicacion de la tecnica. El dia previo a la cirugia se realizo linfogammagrafia a todos los pacientes, y durante el acto quirurgico se procedio a la biopsia radioguiada de los GC. En 10 de los pacientes se realizo inyeccion de azul de metileno antes de la intervencion. Se ha realizado un seguimiento de los pacientes durante una media de 32 meses. Resultados En el grupo de validacion la linfogammagrafia mostro drenaje inguinal en 5/5 pacientes. Fueron detectadas metastasis unilaterales en 3 de ellos. No mostro infiltracion tumoral ninguno de los ganglios linfaticos extirpados en la linfadenectomia. En el grupo de aplicacion, la linfogammagrafia mostro drenaje inguinal en 9/10 pacientes. Se extirparon un total de 19 GC, sin detectarse infiltracion tumoral en ninguno de ellos. En el seguimiento no se ha detectado progresion de la enfermedad en ningun paciente. Conclusiones La localizacion del GC mediante biopsia radioguiada del mismo permite evitar linfadenectomias innecesarias en pacientes con carcinoma escamoso de pene y riesgo intermedio o alto de presentar afectacion ganglionar. La tecnica ofrece una elevada fiabilidad y valor predictivo negativo en el carcinoma escamoso de pene.

Objective To assess the validity of radioguided sentinel node biopsy in squamous cell penile carcinoma. Material and methods Fifteen patients were studied. The first 5 patients were included in a group for validation of the technique, in which a standard inguinal lymphadenectomy was performed after the procedures described below. The remaining 10 patients were included in the technique application group. The day before surgery, lymphoscintigraphy was performed on all patients. During the operation, radioguided biopsy to locate the sentinel node was done. Methylene blue dye was injected shortly before surgery in 10 patients. All patients were followed for an average of 32 months. Results In the validation group, lymphoscintigraphy revealed inguinal drainage in 5/5 patients. Unilateral metastases were detected in 3/5 patients. No metastatic nodes were detected among the nodes removed during inguinal lymphadenectomy. In the application group, lymphoscintigraphy showed inguinal drainage in 9/10 patients. Nineteen nodes were removed, none of which showed tumour involvement. During the follow-up period, no disease progression or recurrence were observed in either patient group. Conclusions Radioguided localization and biopsy of the sentinel nodes can avoid unnecessary lymphadenectomies in patients with squamous cell penile carcinoma and high or intermediate risk of lymph node involvement. This technique shows high reliability and negative predictive value in penile carcinoma.

Introducción. El tamizaje neonatal de Hipotiroidismo Congénito y otras enfermedades heredometabólicas comparten el hecho de que los analitos de interés son determinados en manchas de sangre seca colectada en papel de filtro. La concentración del analito depende de la forma en que son preparados los calibradores y de otras variables que están involucradas en este proceso; como el lote y el tipo de papel de filtro usado, la matriz de los calibradores, el porcentaje de hematocrito entre otros. Material y métodos. Se evaluaron 4 controles preparados en sangre total y ajustados al 55% de hematocrito con diferentes niveles de concentración de TSH, T4 y Fenilalanina cada control fue dispensado en tarjetas de papel de filtro Whatman BFC 180, S&S 2992 y 903™, las concentraciones de cada analito se midieron utilizando los UMELISAS TSH y T4 Neonatal y en el UMTEST PKU. Se realizó un estudio de estabilidad durante 9 meses, para los controles conservados entre 2-8°C, además fueron evaluadas 400 muestras de neonatos colectadas simultáneamente en papel de filtro 2992 y 903™. Resultados y conclusiones. La aplicación de la prueba t para datos pareados demostró que no existen diferencias estadísticamente significativas entre los tres tipos de papel de filtro para un intervalo de confianza del 95% al no producir afectación en la precisión y exactitud de estos métodos. El porcentaje de pérdida de actividad de los 3 analitos estudiados fue inferior al 17%. Los valores promedios de concentración en la distribución de TSH y Phe son ligeramente mayores en las muestras colectadas en papel 903™.

We report a case of a patient with presumed stage IB1 squamous cell carcinoma of the cervix in which FDG PET/CT scan revealed 1 hypermetabolic left iliac node suggestive to be malignant. Lymphoscintigraphy and SPECT/CT studies previous to sentinel node (SLN) biopsy revealed unilateral drainage in the right pelvis. Intraoperative pathological assessment of the SLN showed no tumoral involvement, and the hypermetabolic node revealed macrometastasis. Tumor node invasion can lead to a lymphatic blockage and become false-negative for SLN technique. Although FDG PET/CT has lower sensitivity than surgical staging, this case shows its value as a preoperative imaging technique.

Background and objectives: Hemodialysis needs an arteriovenous fistula (AVF) that may influence the structure and growth of nearby bone and affect bone mass measurement. The study analyzed the effect of AVF in the assessment of forearm bone mineral density (BMD) measured by dual energy x-ray absorptiometry (DXA) and examined its influence on the final diagnosis of osteoporosis. Design, setting, participants, & measurements: Forty patients (52 ± 18 yr) in hemodialysis program (12 ± 8 yr) with permeable AVF in forearm were included. Patients were divided in two groups (over and under 50 yr). BMD of both forearms (three areas), lumbar spine, and femur was measured by DXA. Forearm measurements in each arm were compared. Patients were diagnosed as normal only if all territories were considered nonpathologic and osteoporosis/osteopenia was determined by the lowest score found. Results: Ten patients were excluded and 30 patients were analyzed. BMD in the forearm with AVF was significantly lower than that observed in the contralateral forearm in both groups of patients and in all forearm areas analyzed. When only lumbar spine and femur measurements were considered, 70% of patients were nonpathologic and 30% were osteoporotic. However, inclusion of AVF forearm classified 63% as osteoporotic and a further 27% as osteopenic, leaving only 10% as nonpathologic. Conclusions: Forearm AVF affects BMD measurements by decreasing their values in patients with end-stage renal failure. This may produce an overdiagnosis of osteoporosis, which should be taken into account when evaluating patients of this type.

Although sentinel lymph node (SLN) identification is widely used in melanoma and breast cancer some concerns exist in other malignancies, such as gynaecologic cancers, and this staging method has not been adopted in many centers due to lack of large validation studies. Aim To evaluate the applicability and results of SLN technique in gynaecological malignancies regarding our institution. Method We studied 155 patients with different malignancies (70 vulvar, 50 cervical and 35 endometrial cancers). The day before surgery a lymphoscintigraphy was performed by injecting 111 MBq of 99mTc- nanocolloid in several ways depending on the type of cancer studied. Intraoperative detection of the SLN was always performed by using a hand-held gammaprobe and in 100 cases with the aid of blue dye injection (70 vulvar and 30 in cervical cancer) a few minutes before surgical intervention. The pathology study of SLN was performed in all cases. Lymphadenectomy was done in all cervix and endometrial cancer patients and in the first 35 vulvar cancer patients. Results Pre-surgical lymphoscintigraphy demonstrated at least one SLN in 97% of vulvar cancer patients, 92% in the cervical malignancy and 64% in the endometrial cancer patients. During surgery, SLN was harvested in 97%, 90% and 62% of patients, respectively. The pathology study showed metastases in 24.2%, 8.8 and 4.5% of patients with vulvar, cervical and endometrial cancer, respectively. The false negative percentage was 5.5% in vulvar cancer patients, with 2 cases in the endometrial cancer and without any case in the cervical cancer patients. Conclusion Lymphoscintigraphy is a relatively simple and useful technique to identify the SLN in this kind of tumours. However, in endometrial cancer more effort has to be made to reach a suitable result. Sentinel lymph node biopsy seems to be a reliable technique in vulvar and cervical malignancies.

The sentinel lymph node (SLN) is the first node in a lymph node basin to receive direct drainage from the primary tumour. However, in some cases, lymphoscintigraphy images demonstrate the presence of lymph nodes located in the area between the primary tumour and the first regional lymph node basin. These nodes are called in-transit nodes and have to be considered SLNs as well.It was to determine the incidence and location of in-transit SLNs in patients with malignant melanoma and to evaluate whether it is necessary to harvest them. METHOD. Nine hundred patients with malignant melanoma were included. Lymphoscintigraphy was performed on the day before surgery following intradermal injection of 74-111 MBq of 99mTc-Nanocolloid in four doses around the primary lesion or the biopsy scar.The presence of in-transit SLNs was revealed in 80 patients. During surgery, in-transit SLNs were identified and excised in all but 3 patients (96.2 %). Metastatic cell deposits were identified in these in-transit SLNs in 15 patients (19.4 %), with 4 patients with no tumour involvement of the regional lymph node basin.Lymphoscintigraphy is mandatory in the location of in-transit SLNs. Moreover, although the incidence of these nodes is relatively low in malignant melanoma, the presence of metastatic cells in these in-transit SLNs reaches a significant percentage. Therefore, excision of in-transit SLNs is necessary in all cases.

To evaluate the usefulness of (99m)Tc-Sulphur colloid when combined with leukocyte scintigraphy in suspected prosthetic hip infection, comparing the results with information from (99m)Tc-HMPAO-leukocyte scintigraphy alone.Seventy patients (42 women, 28 men; mean age 68 +/- 13 years) with painful hip prostheses and suspicion of infection were evaluated prospectively. All patients had bone scintigraphy, (99m)Tc-HMPAO-labelled white blood cell scintigraphy and (99m)Tc-Sulphur colloid bone marrow scintigraphy. ESR and CRP levels were measured in all patients. The final diagnosis was made with microbiological findings or by clinical follow up of at least 12 months.Infections were diagnosed in 12 of the 70 patients (3 coagulase-negative Staphylococcus, 2 Staphylococcus aureus, 2 Staphylococcus epidermidis, 2 enterococcus and 3 polymicrobial agents). ESR and CRP values were higher in patients with infection than in patients without infection (51.8 +/- 29.4 vs. 25.4 +/- 16.4 and 2.8 +/- 2.2 vs. 1.1 +/- 1.3, respectively; p0.05). Bone scintigraphy did not show a characteristic pattern to differentiate infection from aseptic loosening. The pool phase of the bone scintigraphy was positive in only 3/12 patients with infection (25 %). Sensitivity and specificity of the leukocyte scintigraphy was 83 % and 57 %, respectively. When the results of the bone marrow scintigraphy were added, these values increased to 92 % and 98 %, respectively.Performing bone marrow scintigraphy significantly improves results when compared with leukocyte scintigraphy alone in the diagnosis of infected hip prostheses. Bone scintigraphy did not help to differentiate aseptic loosening from infection in this series.

To assess the validity of radioguided sentinel node biopsy in squamous cell penile carcinoma.Fifteen patients were studied. The first 5 patients were included in a group for validation of the technique, in which a standard inguinal lymphadenectomy was performed after the procedures described below. The remaining 10 patients were included in the technique application group. The day before surgery, lymphoscintigraphy was performed on all patients. During the operation, radioguided biopsy to locate the sentinel node was done. Methylene blue dye was injected shortly before surgery in 10 patients. All patients were followed for an average of 32 months.In the validation group, lymphoscintigraphy revealed inguinal drainage in 5/5 patients. Unilateral metastases were detected in 3/5 patients. No metastatic nodes were detected among the nodes removed during inguinal lymphadenectomy. In the application group, lymphoscintigraphy showed inguinal drainage in 9/10 patients. Nineteen nodes were removed, none of which showed tumour involvement. During the follow-up period, no disease progression or recurrence were observed in either patient group.Radioguided localization and biopsy of the sentinel nodes can avoid unnecessary lymphadenectomies in patients with squamous cell penile carcinoma and high or intermediate risk of lymph node involvement. This technique shows high reliability and negative predictive value in penile carcinoma.

Presentamos el caso de una paciente de 64 anos con una neoplasia de mama localizada en el cuadrante inferior externo derecho. La linfogammagrafia se llevo a cabo el dia previo a la cirugia mediante la inyeccion intratumoral de 111 MBq de 99mTc-nanocoloide (fi g. 1), que mostro drenaje a las regiones axilar derecha y mamaria interna de ambos lados. La mayoria de los estudios han refl ejado que los tumores localizados en los cuadrantes internos presentan un mayor porcentaje de drenaje en esta zona respecto al resto de las localizaciones1-3. En nuestro caso, presentamos a una paciente con un tumor en el cuadrante inferior externo de la mama derecha con drenaje a la region mamaria interna. Ademas, este caso tambien demuestra que pueden existir vasos linfaticos que comuniquen las dos regiones mamarias internas, lo que explicaria el drenaje bilateral visualizado en las imagenes gammagrafi cas.